Ray's 1987 944 LS1 Build & Swap

nphd2000 wrote:Sure I'll be asking more questions and I'll try to post in appropriate areas...this seemed to be the only active thread.

Welcome to the forum and best on your project. I did my swap a few years ago but still follow builds and help if I can. Agreed there's not a lot of activity here right now. As Ray suggested, do create your own build thread and it'll become a 2nd active thread.

My thread is up there, "Rich's LS Powered..." but I haven't added to it in ages. I used a C5 manual, a.k.a. "2 piece", bell housing. Back then they were a dime a dozen...

Rich

Greetings all, we just got back from SoCal about a week ago and I’m getting back on track.

First a few updates:

Radiator Fitment:
In September I was anguishing over fitment of my Griffin Racing Radiator, specifically the proper LS1 thermostat housing, compatible radiator hoses, sensor fittings, radiator mount modifications, and cooling fan shroud adaptation. This all ended abruptly when I decided to follow forum expert advice and purchase the Texas Performance Concepts (TPC) LSX conversion radiator package.

I don’t believe this radiator package is fully described yet on the TPC web page so you will need to contact Kent for details and to place an order.  However, from my conversation with Kent, I can share with you that the radiator is an all-aluminum custom made, dual-pass, unit that has all the fittings welded in optimum locations for an LSX/944 transplant and includes custom mounting hardware and correct hoses.  Kent has also designed a new custom laser cut aluminum shroud that adapts factory turbo dual cooling fans to the custom radiator.  The fan shroud is key to proper air flow through the radiator at low speeds.

Currently, I’m waiting for delivery which is estimated to be another 7-14 days depending on the shroud fabrication & delivery timeline.  I’ll post an update when the goods arrive along with documentation of my installation experience.

Steering Shaft Linkage “Clunking Sound”
With some help from my neighbor (proud owner of a ’66 Chevelle SS), we tried to track down the source of this mysterious sound.  The steering shaft linkage and all other moving parts are NOT contacting anything on the body or frame.  There is NO discernable play in the u-joints. The sound is only produced in one specific position of the linkage and is there is no mechanical resistance felt that correlates with the sound.

Our conclusion was that the sound being generated is coming from the upper steering shaft u-joint, and that perhaps is has a defective bearing.  I never noticed any sounds during the driving years, or pre-deconstruction, or even during rehab of the steering shaft.  Therefore, I’m taking the “wait and see” approach and moving forward.

Front Sway Bar Installation

After removing the front sway bar, which seems like ages ago, a quick overview revealed that a leaking PS fluid reservoir was continually “bathing” the bushing on passenger side drop link mount, and it was swollen and decomposed.  In the pic below, you can see what the new bushings look like (right side pair) compared to old units.  The damaged passenger side bushing is second from left.

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<Old and new 25.5 mm sway bar bushings>

BTW… before purchasing new bushings, I measured my sway bar diameter to determine the correct bushing size.  I was pleased to find that I have the optional 25.5mm unit vs. the standard 23 mm unit.  YAY!!      This was also confirmed by the Porsche PN on the drop link mount and clamp, both ending with “01.”

I ordered a pair of new stock replacement bushings from 944OnLine for $33 plus tax and shipping.

As usual, I rehabbed the sway bar, drop link mounts, and all the connection components before reinstallation.  A fresh coat of paint makes all things “like new!”

…Except the bushings that is.  Sway bar end bushings and the control arm grommets were all in good shape and I suspect they were replaced at one time.

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<Rehabbed Sway Bar Hardware & New Bushing>   <Drop Link Clamp Porsche Part Number>

The install was straightforward.  It always helps to have plenty of BEFORE pictures to make sure everything goes back together properly.
• First, I coated the inside of each sway bar bushing clamp with Syl Glide and inserted the new bushings.
• Then I placed each clamp in my bench vise (with soft jaws) and closed the clamps far enough to install the clamp bolts through the drop link mounting brackets.
• After removing the clamps from the vise, I tightened the clamp bolts and M8 lock nuts with a 13mm socket and 13mm wrench until they were snug.
(I used zinc plated flat washers on each side to preserve my paint job!)
• Next, I lubed the ends of the sway bar with Syl Glide so I could easily slide the mounting brackets with new bushings into their proper location.
• I could then fully tighten the M8 lock nuts to 17 ft-lbs.
• Finally, I slid the sway bar control arm link mounts over the ends of the sway bar.  

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<Front Sway Bar Before and After Reconditioning>

With the sway bar fully reassembled, the next step was to clean up the frame rails where the drop link mounts connect.  I believe this area was the last remnant of oil and grime from all the old factory PS reservoir leaks.  After a good cleaning with degreaser, surface prep with CRC Brakleen, and a coat of Rust-Oleum “Cherry Red,” the mounting area looked pretty good!

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<Drop Link Mounting Area Before and After>

To install the sway bar, the end drop links must first be connected to the lower control arms.  Use a stool to support one end while connecting the opposite end.   I coated each rubber grommet with Syl Glide, sandwiched the control arm between the link grommets and (after both ends were connected) tightened each M10 mounting nut to 18 ft-lbs. with a 17mm socket.  The mounting nuts are supposed to be locking nuts but mine were NOT, so I added lock washers.  When installing the remaining side, you will likely need to jack up the lower control arm to make the connection.

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<Lower Control Arm Sway Bar Drop Link>                         <Sway Bar Installation Jack Set-up>

Once the sway bar end links were connected to the lower control arms, I used my floor jack and a board to evenly raise the sway bar until the drop link mounting brackets could be simultaneously bolted to the frame rails.
 
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<Drop Link Mount Position Before Jacking>        <Drop Link Mount After Jacking w/Bolts Installed>

Note:  Upon examination of the M8-1.25 x22 drop link mounting bolts, I noticed significant bolt wear on two of them just below the head.  Clearly, they had come loose!  

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<Damaged Drop Link Mounting Bolt>

To prevent this from reoccurring, the replacement bolts were installed with blue Loctite and lock washers.  Each was tightened to 17 ft-lbs. with a 13mm socket and 8” long 3/8” drive extension, after they were hand-started and the mounting brackets were both snug against the frame.

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<Completed Front Sway Bar Installation>

With the front sway bar installed, the next step is to complete the Hydro boost installation.

That will be next…

Good job on the sway bar refresh. I currently run the tpc radiator with a single fan, I think it's 14", maybe 16" I forget. It works good but thinking of wrapping a shroud around it and a front air deflector angled downwards to direct air to top of rad. The Temp range after an hour driving are 189F cruising to 205F in stop and go 80F ambient outside temperature. I have problems over 92F its just an oven. What really helped was the painless 70amp relay. The 30/40amp relay on a bigger spal performance fan did not do well. The tpc fan fits like a glove and I had the spal brackets welded to it for lowest profile on room. Not sure of the difference between lindsey racing fan, wizard cooling or tpc quality wise but either will fit and the most tubes is the one to get I guess. Your build is looking really good so keep up the good work.

Dave

Quick question. I noticed you are utilizing crossmember drop spacers but none on the sway bar. Are they not necessary? I would assume you would want to drop the mounting points of the crossmember, control arm, and sway bar brackets all the same distance. TIA

nphd2000,

Excellent observation.  Your assessment is correct in that the the control arms are now mounted lower than stock by 1/2 inch while the drop link mounts remain in their original position.

The thing is, when both control arms move the same amount in the same direction (up or down), the sway bar simply rotates within the drop link bushings to accommodate the change.  Hence, sway bars don't affect ride height.

On the other hand, what they are designed to do is resist "differential" vertical movement in the front suspension by virtue of torque resistance in the sway bar shaft.  This provides additional stiffness in the individual wheel suspension and reduces roll when going through a turn.  This explains why a bigger diameter sway bar provides for "flatter" cornering and improved tire contact.

So to answer your question... IMHO, mounting spacers for the sway bar drop link mounts are not necessary.

I'll buy that logic. I guess if there is no contact between sway bar and control arm at full droop it shouldn't be an issue. I will start my sway bar restoration over the weekend....I have a bulging bushing on the passengers side as well! Over the winter I will tackle the brake rehab as you did as well. May be asking you a few questions about where you sourced the parts for re-build.TIA

I wish I had your work space BTW

This post is a follow-up to article “Hydro-Boost Install – Part 1” that I posted July 8, 2021.

As a reminder, below is a pic of the TPC Hydro-boost (HB) kit. (Sans the TPC transaxle support plate!)

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<TPC Hydro-Boost Kit>

In Part 1 the HB unit was installed.  Now that the engine, front suspension, and power steering rack is in place, the next step was to prepare and install the high- and low-pressure hoses connecting the HB to the PS rack and PS pump.

The TPC kit includes the following connection components:

1 – HB adapter block with 2 -AN 6 fittings and one 5/8” hose end barb already mounted
4 - reusable steel high-pressure connectors for 5/8” hose.
• 2-90 deg. units for HB connection of high-pressure line in from the GM PS pump, and the high-pressure line out to the PS rack gear box.
• 1-90 deg. unit for the GM PS pump connection of the high-pressure line out to the HB
• 1-45 deg. unit for the PS rack gear box connection of the high-pressure line in from the HB

1 - reusable composite low-pressure connector for 5/8” hose.
• 1-45 deg. unit for the PS rack gear box connection of the low-pressure return line out to the GM PS reservoir
1 - brass T for a 5/8” hose connection to the GM PS pump reservoir return line from HB low-pressure line.
4 - SS screw type hose clamps
1 – AN 6 fitting for the GM PS pump high-pressure outlet
2 – AN 6 12mm fittings to replace the PS rack high- and low-pressure banjo-bolt fittings
9.0 ft of 5/16” ID steel braided, high-pressure hose line
7.7 ft of 5/16” ID fiber reinforced rubber, low-pressure hose line

For this “Part 2” installment, I was able to build both high-pressure lines and get them installed.  

Here’s how I did it:

I decided to build the line from the PS pump to the HB first, and began by installing one of the 90 deg. reusable connectors to the end of the supplied high-pressure line.  I had never used these before and I imagine many readers may not have as well, so I carefully documented the process.  If you’re unfamiliar with their construction, they consist of two pieces…a hexagonal exterior fitting that threads onto the outside of the hose with left hand threads, and an AN connection end that has a tapered end that fits inside the hose.  The two pieces thread together using a very fine right-hand thread and form a high-pressure connection.
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Step 1:  Mark the full insertion depth.  I used blue painter’s tape.

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<Insertion Depth for Full Clamping Effect>                    <Internal Hose Cutting Debris>

Step 2: Clean the cutting debris from the hose.  I used compressed air and then some Brakleen on a paper towel to clean out the end 2-3 inches.  We don’t want any rubber shavings or wire remnants in our PS fluid!
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<Completed Fitting Installation>                        <Routing the High-Pressure Line to the HB>

Step 3: Connect the completed fitting to the PS pump and route the loose end of the hose along the cylinder head adjacent the fuel injectors and under the coil pack harness.

Step 4: Mark the cut length and fitting orientation for the HB connection fitting.  I installed the 2nd 90 deg. fitting in the HB just tight enough for this purpose.  I marked the tape with a black line indicating the plane of the 90 deg. fitting.

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<Marking the Hose Length at the HB>                           <Marking Orientation Lines>

Step 5: Cut the hose to length.  I used a cutting wheel to get the job done, followed by some filing to remove any wild steel wires, and then I trimmed the fiber mesh wrapping with shop scissors to make a nice clean end.  When I was done with the outside, I cleaned out the inside with compressed air and swabbing as previously noted.  
NOTE:  The clean-up procedure is essential for every cut.

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<Hose Cutting with a Cut-off Wheel>                                      <Fully Prepared Hose End>

Step 6: Mark the full hose insertion depth and mark the hose alignment with the fitting.  It is important to get the alignment right for easy connection because high-pressure line has limited flexibility.

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< Insertion Depth for Full Clamping Effect >                   <Alignment of the Fitting and Hose>

Step 7:  Remove the piece of tape used to mark the cut line and thread on the exterior hose fitting.  After wrestling with two wrenches to assemble the first fitting, I resorted to using my bench vice for future assemblies making sure the alignment was correct when the AN end of the fitting was fully tightened. I also used just a touch of synthetic motor oil on the tapered shaft to facilitate tightening.

Step 8: Install the hose at both ends (loosely).  The final completed build used a hose length of 29 inches.

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<Completed Hose Connections for PS Pump to HB>

Step 9: Build the high-pressure line from the HB to the PS rack gear box (PSR).  To start, I installed the 3rd 90 deg. fitting on one end of the remaining length of HP hose.  Then I connected the fitting to the HB TPC adapter block and snugged up the connection.

Step 10: Route the free end of the HP hose along the length of the cylinder head parallel with the PSR to HB hose previously installed.

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<HB to PSR HP Hose Top Routing>                                    <HB to PSR HP Hose Front Routing>

Step 11:  At the front of the engine, fish the HP hose down beside the PS pump and then behind the alternator, under the engine mount upright, and between the PSR gear box and engine block.

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< HB to PSR HP Line Bottom Routing>                < HB to PSR Connection Cut Length and Alignment >

Step 12:  Install the 45 deg. connection fitting on the PSR HP port fitting (lower) facing up, and establish the desired cut length and hose orientation.  Use enough hose to go past the gear box and make a U-turn to achieve a good alignment.  There is ample clearance from the header but I will be installing heat wrap on the PSR hoses just for insurance.

Step 13:  Once the hose is marked, remove it, then install the 45 deg. connection fitting, and reinstall the completed hose for a final connection.  The final completed build used a hose length of 64 inches.

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<HB to PSR HP Line U-Turn>

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<Completed HP Hose Installation>

At this point, all the connections are just hand tight.  After I build the low-pressure line and all fits well, everything will be fully secured.

Next topic, building and installing the low-pressure lines.

This post is a follow-up to article “Hydro-Boost Install – Part 2” that I posted October 20, 2021.

In Part 1 the HB unit was installed.  In Part 2, I fabricated and installed the high-pressure lines from the PS pump to the HB and from the HB to the PS rack gear box.  

Below are the TPC kit parts I used for the low-pressure lines:

7.7 ft of 5/16” ID fiber reinforced rubber, low-pressure hose line
5 - SS screw type hose clamps
1 - 45 deg. reusable composite low-pressure AN connector for 5/16” hose into the PS rack gear box from the low-pressure return line between the HB and the GM PS pump reservoir.
1 - Brass "T" to connect the PS rack low-pressure 5/16” hose to the 5/16” low-pressure return line from the HB to GM PS pump reservoir.

For the low-pressure lines, the hose is easily cut with a sharp knife and the connections are made using standard SS screw type hose clamps.  I thought this Part would be a “walk in the park,” but it turned out to be a little more difficult than I expected.  Here’s how I did it.

Step 1)  I connected the hose to the HB low-pressure return nipple, routed the line around the strut tower, then forward along the frame rail, and up to the GM PS pump reservoir nipple.

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<LP Line Connection to the HB Unit>                                  <LP Line Connection to Strut Tower>

Step 2)  Next, I inserted the 45 deg. LP AN connector into one end of the remaining length of 5/16” hose with one of the hose clamps loosely applied.  Note: Be sure to position the clamp for easy access when under the car.

Step 3) From under the car, I connected the LP AN fitting on the PS rack gear box fitting (hand start only) and then “fished” the open end of the hose up above the steering shaft lower U-joint and out the front between the block and the motor mount upright.  Note: Once again a sizeable loop in the hose is needed to get the proper alignment with the PS rack gear box fitting and the necessary extension above the steering shaft U-joint.

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<LP Line Connection to Rack Gear Box>                <LP Line Loop at Rack Gear Box>

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<LP Line Mounted to Block>                                   <Routing the LP up to the PS Pump Reservoir>

In the pics you can see that I used a bolt on hose clamp to secure the LP line to the block.  This stabilized the loop in a favorable position.  It also allowed me to redirect the LP line up to the PS Pump Reservoir without impacting the loop position.

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<Marked Hose Length and “T” Location>                <Brass "T" Installation Guide>

Step 4)  Once the LP line from the PS rack gear box was redirected up toward the reservoir, I pulled it to the desired length and then marked the LP line I just installed between the reservoir and HB for insertion of the brass "T" connector.  I used blue tape to mark the optimal cut locations.

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<Completed “T” Connection – Top View>                       <Completed “T” Connection – Bottom View>

To make the “T” connection, carefully determine the orientation of the clamps for easy access, and the orientation of the “T” itself.  Next, while under the car, install a clamp on the LP hose from the PS rack, insert the stem of the “T,” and fully tighten the clamp.  Install a clamp loosely on the short hose to the reservoir and insert the front branch of the “T.”  Next, install a clamp loosely on the long hose from the HB, fish the lines with the “T” already connected into position, and then insert the back branch of the “T” into the LP line to the HB.  Check the alignment and position of the “T” and all the hose segments are as desired and fully tighten all clamps.

Currently my LP lines are well aligned with good radii, but the header clearance in the “at rest” condition is only about 1 inch.   I put some heat shield on the endangered area for now but moving forward I plan to install another LP Line clamp on the overflow reservoir mounting stud.  There is plenty of flexibility and length in the LP line to the HB to do this.  I’ll post an update of what that looks like in a day or so when I finish cleaning up and reinstalling my overflow reservoir.

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< LP Line Exposure >

With all the HB/PS lines in place, I went ahead and tightened all connections.  By far the most difficult were the AN fittings on the PS Gear Box.  Getting a standard 18 mm wrench on these two fittings is just barely doable and there is minimal wrench travel.  Fortunately, flipping the wrench repeatedly allowed me to adequately secure the connection…I HOPE!

Next up, relocating #5 and #7 coil packs (I think).

So I pulled the inner fender on the drivers side to facilitate working on the front brake line to the Master Cylinder.

I expected 34 years of dirt etc. but this thing????  

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The lower hose coming out of this unit goes under the car and terminates (open) just past the end of the driver's door.

I haven't determined yet where the top hose is coming from, but I have a hunch this is some sort of emissions component for the fuel system.

The surprises never end!!

Yep. Fuel tank purge. Goes to the top of the fuel tank. Will send fumes to the engine through the two vacuum operated valves just in front of the fuse box. I tie it back into the intake manifold similar to how the 944 intake was plumbed. You can also just put a small filter on the end of the hose where the two vacuum valves were if they were removed.

Well it’s been a while since my last post, but it took some time to iron a few things out.

First, I wanted to wrap-up installation of my GM power steering pump and reservoir after building the lines to the HB and PS Rack.  Turns out I was missing the steel clips that hold the reservoir to the PS Pump.

After some extensive searching and visual matching of various factory GM PS Pump clips, I found a pair on Summit Racing for $9.99.  Tax and shipping pushed that cost to $23.80.

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<GM Compatible PS Pump Reservoir Clips>

Unfortunately, the clips cannot be installed with the PS Pump on the engine so the new hydraulic lines must come back off, along with the serpentine belt, and the pump itself.  I’m pretty sure I can access the pump mounting bolts thru the Turn One spoked pulley. One step forward…two steps back!  

Now if I could just find where to buy a new reservoir O-ring!

Turning my attention to the coil pack relocation, I did a dry fit of the Master Cylinder (MC) on the HB and discovered that coil packs #3, #5, & #7 all must be relocated.

LEVA turned me on to a double stacked coil pack option that worked for him.  I thought it would be a perfect solution for me as well, but it turns out my Holley valve cover combined with the LS-2 coil packs I’m using, push the height of a “double stack” above the intake and will undoubtedly interfere with the hood closing.  The concept did give me an idea for a solution which involved fabricating mounting plates that would allow moving coil pack #3 forward about 2 inches to clear the MC.  
I used plain aluminum strap 1/8” by 1”, bench vise, hack saw, file, and hand drill to make the brackets. Below are pics of the raw pieces assembled for a test fit.  I’ll polish them up for final assembly… perhaps paint them black.  Note that I have yet to rehab the MC.


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<Coil Pack #5 Mounting Bracket>                      <Coil Pack #1 & #3 Mounting Bracket>
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<Coil Packs #1, #3, & #5 Mounted>                   <Coil Pack #7 Strut Tower Mount Location - Top>
 
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<Coil Pack #7 Mount Location - Front>                 <Coil Pack #7 Mount Location - Side>

Sequence of assembly:
1) Install coil pack #5 to the mounting bracket with 2-M6-1.0 x 35 mm flange bolts, 1/4” dia. by 1/2” long copper tubing spacers (not shown), and M6 lock washers and nuts.  The spacers lift the coil pack off the bracket slightly and allow tightening of the mounting bolts without putting any load on the coil.
2) Lay the #5 mounting bracket in position on the valve cover over the original #3 mounting boss locations.  Place the #1 and #3 mounting brackets on top of the #5 bracket, bolting them in position (loosely) with 2-M6-1.0 x 20mm flange bolts.
3) Install coil pack #1 with 2 – M6-1.0 x 25mm flange bolts with blue Loctite, torqued to 7-8 ft-lbs.
4) Remove the loose bolts securing the #5 mounting bracket, one at a time, and reinstall with blue Loctite, torqued to 7-8 ft-lbs.
5) Install MC (procedure pending in a subsequent post)
6) Install coil pack #3 on the new mounting brackets using 2 – M6-1.0 x 20mm flange bolts, lock washers and M6 nuts, torqued to 7-8 ft-lbs.

A dry run assembly proved that everything fits together well, and all surrounding components remain accessible for future servicing.  Mission accomplished!!

Next steps include:
1) Mount coil pack #7 to the strut tower.  The pics show the approximate desired location and is resting in place with the spark plug wire connected so there is no mod needed.  Mounting will be via a simple aluminum L-shaped bracket, 1- M6 self-taping sheet metal fender bolt, and 1-M6-1.0 x 20mm bolt, lock washer and nut.
2) Make a longer #5 MSD 8mm spark plug wire.
3) Extend the #5 and #7 coil pack wiring harness plugs.

Master Cylinder rejuvenation and installation is next…

I finally got around to pulling the pump off and installing the reservoir.  The O-ring looked and felt like new, so I lubed it up and reused it.  The “Performance” brand clips I purchased fit just fine however my pump casting has nothing for the clip locking mechanism to engage so I suspect they are for a different set-up.  The positive news (I think) is the clips are quite tight as I had to tap them into position with a small hammer, and the pump mounting plate prevents the clips from backing off more than about a ¼ inch.  Below are some pics for reference:

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<Clips in Pre-set Position>                                                       < Clips Fully Installed>


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<Locking Tab w/No Contact>                                               <PS Pump Reinstalled w/Reservoir>


When I removed the pump, I found that the plated mounting bolts already had some light corrosion as well as galvanic action with the aluminum mount plate.  To stop this from happening again, I cleaned up the bolts and coated the shafts with a thin coat of anti-seize to prevent corrosion.  I used Blue Loctite on the bolt threads and torqued them to 18 ft-lbs.

Next is an update on my homemade coil pack relocation brackets....

I prepped my homemade aluminum brackets for paint and applied 2 coats of primer followed by 2 coats of flat black high temp paint.  

They turned out decent, but the flat black shows scuff marks that look like shinny spots.  No biggie…these brackets will mostly be out of sight.  Below are some pics and a fabrication drawing if you think you might be going this route.  

You will likely need to make modifications to fit your valve cover and coil packs.  Note that one end of the Coil Pack #7 mounting bracket (the Z shaped one) has one hole for the strut tower self-taping bolt and another near-by to engage an existing threaded stud for stability.  The hole at the other end, and all the holes in the other brackets, are ¼” diameter.  I’ll post a pic of the completed assembly as soon as I get my master cylinder cleaned up.

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<Coil Pack Mounting Brackets Painted Flat Black>

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<Coil Pack Relocation Bracket Fabrication Drawing>

Master Cylinder rejuvenation and installation is next…

It has been somewhat of a rollercoaster ride since my last post but I’m making progress!

With the coil pack relocation figured out, I moved on to reconditioning my factory Girling brake master cylinder and reservoir.

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<Brake MC Before>                                      <New Reservoir Grommets and Mounting Gasket>

The 1st step was to purchase some new seals…specifically, new reservoir mounting grommets and a new rubber O-ring gasket for the MC mount. I did not rebuild the brake MC so hopefully that won’t bite me in the butt later.
Brake MC O-ring – 944OnLine PN 251 611 243 $4.49 plus tax and S&H
Brake Fluid Reservoir Grommets (2) – 944OnLIne PN 911 355 922 00 $11.90 plus tax and S&H

The 2nd step was to remove the reservoir.  After completely removing the brake fluid, this is done with a two-handed effort, and I needed to clamp the MC body in my vise to make it happen.  After that, cleanup of the MC body was simple enough using various wire wheels on my cordless drill to remove the aluminum oxidation. I cleaned the plastic reservoir with a solution of water-based degreaser (50/50 mix) and a ½ cup of bleach, using the “soak and shake” approach. It took about a week to dissolve the "junk" at the bottom. That worked out OK as I still had plenty of other things to do. I used compressed air to chase all the water out and let it air dry for another week.  Very important!

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<Girling Brake MC w/New Silver Caliper Paint Job>                <Cleaned up Brake Fluid Reservoir>

Prior to the pending final brake MC install, I needed to check the HB brake pedal pushrod to make sure it was fully extended. I was supposed to do this when I installed the HB, and apparently, I did because it was correct…Yay!!  However, I did notice while under the dash that the clutch master cylinder had rust streaks coming from the dust boot.  This was NOT a good sign, more this later.

The 3rd Step was to test fit the MC on the HB/TPC adapter block using the new TPC MC pushrod. The pushrod comes with a groove milled in one end. As per Kent at TPC, this is a carryover for use with a Mustang MC and not relevant when using the Girling MC. I put some white lithium grease on each end, placed the grooved end facing forward, and proceeded with the test fit.  

Without the new MC O-ring gasket installed, there was a 0.025 in. gap between the MC and the TPC adapter. The new MC O-ring measures 0.106 in. and the depth of the O-ring groove in the MC housing is 0.079 in. Subtracting the groove depth from the O-ring thickness indicates a 0.027 in. O-ring projection which is just slightly larger than the test fit gap. The conclusion is that compression of the O-ring will occur for a good seal with only a negligible amount of MC piston compression under static conditions.
Good to go!!

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<MC Test Fit Without the O-ring>                                        < Grooved Push Rod End>

The last thing I wanted to do before finalizing the brake MC install was to connect the GM clutch slave cylinder hydraulic line to the clutch MC. Unfortunately, I found more evidence of rust coming from the output port of the factory clutch MC. Replacement of this last stock component makes perfect sense right now considering my overall investment, so I gave Kent at TPC a call for his recommendation.

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<Rusty Brake Fluid in the Outlet Port>

He fixed me up with his TPC modified Tilton 76-875 MC kit and custom firewall brace. The Tilton MC has a matching stroke, but the bore is larger at 7/8” diameter vs the Porsche unit with a 3/4” bore. This provides increased fluid volume to the GM slave cylinder which is apparently needed for full disengagement. Kent slots the Tilton MC mounting holes for “ease” of installation and supplies all the hardware and brake line hose needed, including new copper plated locking nuts, an inlet banjo bolt with a 1/4 in. brass hose barb, and SS hose clamps.

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<TPC Clutch MC Kit and Firewall Brace>

The firewall brace is a TPC custom creation and is recommended when using the heavier LS clutch options. This TPC kit goes for around $340 plus tax and shipping. Contact TPC for more info.

NOTE: The Tilton MC requires a slight modification to the inner fender for the necessary clearance. More on that later. You can save yourself tons of grief if you replace your old clutch MC before installing the engine and HB.

So…with my engine and HB in place, I began the process of removing the clutch MC.  

Step No. 1 was to disconnect the clutch MC pushrod from the clutch pedal. It seemed easy enough as only a snap clip holds the clevis on the pin. It is clearly visible in the photo below.

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<Clutch MC Pushrod and Clutch Pedal>

Once I was under the dash with a flat screwdriver and needle nose pliers in hand, I soon realize that the camera view is NOT possible unless your head is the size of an orange. The clutch pedal fully obscures sight of the retaining clip making it impossible to remove with a single tool or hand. I was about to extract myself from the car and get tools to disassemble the push rod, when I got what I can only explain as a “divine inspiration.” Without any thought process, I pushed on the clutch pedal and the spring preload slammed it to the floor since there was no fluid resistance. I was startled but when I opened my eyes and looked up, the retaining clip was clearly visible in that position!!! I just reached up with my screwdriver and popped it off. The pressure of the preload spring prevented removal of the clevis from the mounting pin, but simply pulling the clutch pedal back to the undepressed rest position released this pressure and the clevis and washer came off easily.  Amazing!!

Step No. 2 was to remove the clutch MC. Under the hood, clearance around the MC is extremely tight and removing the two 13 mm mounting nuts was looking problematic. What worked for me on the engine side nut was a 3/8” drive 13 mm socket directly on my Snap-On ratchet. I first tried a 13mm boxed end micro-ratchet wrench, but I thought it didn’t fit because I failed to pre-rotate the head to match the nut and there is little clearance between the MC housing and the nut.  In hindsight, it will work for removal. For the fender side nut, I used the ratchet again but needed a universal and a 3 in extension.  

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<Removing the Engine Side Nut>                                     <Removing the Fender Side Nut>

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<Clutch MC Mounting Location>                                       <Test Fit of Firewall Brace - NICE>

Step No. 3 was to set up the Tilton MC push-rod to match the stock pedal positioning. To do this, I used the factory MC as a guide. As suspected, the cylinder bore was completely rusted, and sure enough, the piston would not return from the fully depressed position. The rusting occurred because there was no water seal between the MC and the firewall.

I measured the distance to the clevis hole and then matched that distance with the Tilton clevis with the piston in the fully depressed position. I had to add the thickness of the firewall brace for the correct dimension. Going thru this process confirms that the fully depressed clutch pedal will never result in the Tilton MC piston bottoming out and becoming a travel stop. I suspect some reported firewall deflection problems may have originated from an excessive push rod length. This Tilton MC unit has the same piston travel as the Porsche unit so clearly TPC has done their homework. I fully expect the clutch pedal rest position to be at the stock location, and a full clutch stroke will not jam the MC piston.


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<Porsche – Tilton MC Comparison>

Step No. 4 was to test fit the Tilton MC with the input banjo bolt barb installed.  The test fit revealed that an extension of the factory fender clearance depression was needed.  

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<Test Fit of Tilton MC>                                                         <Area Subject to Modification>

The black hash lines indicate the apparent interference and location of needed inner fender modification. I combined two 6” x ½” drive extensions, wrapped some electrical tape around the end, and used the assembly as a drift. Energy was supplied by a 16 oz. framing hammer. If you plan to do this, be sure to achieve a perpendicular striking angle for best results.

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<Fender Modification Tool>                                                   <Completed Modification>

The depression I created is marked by the cross-hatched area and was just enough modification to install the MC. A little clean-up of the fender surface and a coat of Rust-Oleum Cherry Red was the final touch.

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<Test Fit after Modification>                                     <Finished Modification – Hardly Noticeable!>
Step No. 5 was to install the 1/4 in. ID brass inlet barb and banjo bolt. This port is threaded for an AN4 male fitting as an option. The thread is 7/16” x 20 SAE and it seems no one makes a compatible 90-degree elbow that is any more compact than the banjo bolt arrangement.  

NOTE:  It is critical for a good seal to thoroughly clean all mating surfaces before assembly. For added insurance, I used a thin layer of liquid Teflon thread sealant on each face of both copper crush washers. I tightened the banjo bolt to ~20 ft-lbs, which should be plenty. Tightening the banjo bolt after installation is not an option. On the upside, this is not a pressure connection so hopefully the sealant will do the trick. For the record, I placed the flat side of each washer against the brass barb and positioned the barb facing forward about 40 degrees from horizontal.  

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< Inlet Port Clean All Clean>                        <Banjo Bolt, 1/4 in. Hose Barb and Crush Washers>

BTW: I researched the use of Teflon (PTFE) in contact with brake fluid and found the following information from the Gallagher Fluid Seals, Inc. website:
“Polytetrafluoroethylene (PTFE) is commonly known as a coating for pans under the DuPont trade name Teflon. It is also superbly suited as a sealant and is superior to many materials in specific ways. For example, it can be used at low and high temperatures and in combination with gasoline, solvents, water and other polar media such as lyes, standard lubricants and brake fluid. PTFE’s chemical resistance is nearly universal.”
     

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<Completed Hose Barb Installation>

Step No. 6 was to install the Tilton MC and firewall brace with waterproofing materials between all the layer interfaces. I used black windshield bead seal in various “custom rolled” rope sizes to get the job done. A final U-shaped length of bead seal was used on the top of the MC body between the MC and the firewall. I also used black Gorilla Tape on the friction interface with the strut tower.

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<Windshield Bead Rope Application>                  <Gorilla Tape on the Brace/Strut Tower Interface>

Note: The Tilton MC dust boot does not fit thru the firewall hole and is next to impossible to install from the inside under the dash.  This is not a big concern provided a watertight seal can be obtained between the MC and the firewall.

I pre-installed the firewall brace using the old factory 13 mm nuts to properly position it and to compress the windshield seal. I put another arch bead of windshield seal over the top as shown in the pic below.  

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<Firewall Brace Pre-Install>                                 <Clutch MC Installed>

Step No. 7 was to remove the factory nuts and install the MC using the new 12 mm cooper clad lock nuts supplied by TPC. This was very tricky due to limited access. On my 1st attempt using my fingers, I dropped the nut and had to remove the MC to retrieve it. The solution was to use a magnetic probe to assist installation of the nuts by hand. Each was tightened to 15 Ft-Lbs as per my Haynes Manual, and I attached the TPC 3AN outlet line to the GM Slave cylinder.  

NOTE: The engine side nut can be tightened with a 12 mm socket and 3/8” drive ratchet.  The fender side nut is another matter.  I used a homemade aluminum 12 mm “half-wrench” to get it snug but I still need to make a custom steel wrench for the final tightening.  It can only be tightened in increments of about 1/4 turn.  BTW…forget using a torque wrench, there’s no room.

Finally, I put yet another bead of windshield seal at the top of the MC housing to complete the firewall seal.

Step No. 8 was to reconnect the clutch push-rod clevis to the clutch pedal which is the reverse of the removal procedure. With the clutch pedal in the return position, attach the clevis. It should be very close to an exact fit.  If not, adjust the push-rod length by rotating it in the clevis and then tighten the lock nut. Depress the pedal and install the washer and retaining clip. A little spray white lithium grease on the pin finished the job. Lastly, return the clutch pedal back to the undepressed rest position.

Next up is the installation of the brake MC and the driver’s side coil packs….

With the clutch MC replaced, that work space could now be filled with the brake MC and driver’s side coil packs.

Preparation for installing the brake MC started with checking the torque on the TPC MC/HB adapter plate.  I tightened mine to 25 ft-lbs.  

Next, I installed my custom coil pack relocation brackets for coil packs #3 and #5 because one of the bracket mounting bosses is partially blocked by the brake MC.  I also mounted coil pack #7 on the shock tower while I had clear access to the #7 spark plug and plug wire.  This required drilling a 3/16 in. hole in the shock tower for a 3/16 diameter SS sheet metal bolt.  I used sealant on the threads to prevent rusting, a flat washer, and a lock washer.

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<Coil Pack #7 Mounting Bracket>                                         <Coil Pack #7 Spark Plug Wire Routing>

After that, I reapplied white lithium grease on the MC push rod ends and fully inserted it by hand into the HB.  To prep the MC, I coated the rubber O-ring with Syl Glide and installed the MC.  Next, I coated the MC mounting bolts provided by TPC with anti-seize, started them by hand, and torqued them to 20 ft-lbs.

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<Coil Pack Bracket Pre-MC>                                                     <All Coil Packs and MC in Place>

After the brake MC was fully mounted, I completed the installation of coil packs #1 and #3.  Recall that coil pack #5 is attached to the relocation bracket before the bracket is installed. I set the brake fluid reservoir in place just to get a visual and to be sure there were no conflicts.

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<Test Fit of Brake MC Reservoir>

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<Top Side View of Brake MC, Clutch MC, and Coil Packs Installed>

The next steps include: rebuilding the brake lines, installing the reservoir, connecting the clutch MC return line, and making replacement spark plug wire #5.

I'm getting there....

In my last post, I covered installation of the Brake MC. This post will focus on the modifications needed to connect the brake lines, followed by a short bit on making the #5 spark plug wire.

First, it is of utmost important to understand and use the same METRIC brake line hardware Porsche uses. (An exception would be if you are using an aftermarket MC that uses SAE connections.) Metric brake line is labeled 3/16” diameter / 4.8 mm (rounded up from 4.76 mm) x whatever length you buy, measured in inches/cm. Metric brake lines use DIN (bubble flare/ISO) ends vs. SAE (45 degree inverted/double flare) used in domestic cars. Single flare ends are never to be used for brake lines. The end fitting or “tube nut” for a bubble flare is a steel M1-3, 10mm x 1.0mm fine thread, male nut with a non-threaded lead. The non-threaded lead is important for the proper seal of the bubble flare.

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<Metric Brake Line Parts Label>                             <45 Single Flare, Double Flare, & Bubble Flare>

The Girling brake MC and all other Porsche brake components are designed for bubble flare connections. Below is a listing of the components I used to extend the rear brake line, extend the front passenger side brake line, and replace the front driver’s side brake line.

Poly-Armour European PVF (Poly Vinyl Florine) Coated Steel Brake Line 3/16 inch x 40 inch
PAE-340 Metric Brake Line / Metric Bubble Flare
Advance Auto Parts - $7.59 +tax

3/16 Inch Brake Line Bubble/ISO Flare Fittings and Unions, Metric 10x1mm Threads for 3/16 Inch Tubing (Pack of 6)
The Stop Shop - $10.75 + tax and shipping

NOTE: Although 3/8 inch x 24 UNF thread tube nuts will thread into M10x1.0 connections, they will strip when tightened. You do NOT what to go down that road!

In preparation for the job, I took inventory of my tools and realized I needed a few things. For instance:

• 3/16” tube, bubble flaring tool. I settled on the Capri 3/16 in. Double Flaring Tool (CP21110-316) for $40 through Amazon. The 1st step when making a double flare is a perfect bubble flare.
  

• 3/16” Tubing bender. I went with the 1/8, 3/16, & 1/4, 0-120 deg. unit at Harbor Freight for like $9. I found out later that It looks exactly like the $15 Capri unit without the labeling.
  

• Handheld tubing bender pliers. These are needed to straighten out some of the existing bends in the factory brake lines. Again, I went with the HF unit for $10. The jaws needed a bit of filing with a rat-tail file to remove some sharp edges, but otherwise they worked like a charm!
  

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<Brake Line Fabrication Tools>

Below is the process I went through for the rear brake line reconnection. This is the line that comes from the front of the MC through the external proportioning valve. I took a similar approach with the passenger side front brake line. The driver’s side brake line, however, was replaced in its entirety, fabricated from the remaining length of new tubing.

1) Cut the factory line.  I cut the factory brake line just beyond the firewall.  Be sure you leave enough length to accommodate a new tube nut and the flaring tool BEHIND the end to be flared. For me, the minimum distance was 1-7/8 inches. My standard full-size tubing/pipe cutter was too big and consequently complicated a very simple procedure. A mini-cutter can be purchased for about $20 and in hind sight, I think it would be worth it. The piece of stock brake line removed was set aside for use rebuilding the passenger side front brake line.

2) Make the bends. I positioned the tube nut all the way on the end of the new line and made a clean 90 deg bend as close as possible to the end. Tube nuts cannot be moved across even small tubing bends or kinks. After a few minor bends in the new line segment, I got it aligned with the remaining length of the original line and marked the proper cut length. You will need a measuring tape to get your lengths just right for the other lines…too short and you must start over, too long and your final fabrication effort might look a bit “whimsical.”

3) Cut the new line. Ends of brake line (new or old) must be prepped for flaring. Cutting should be done gradually to prevent distortion. Irregular cuts (because your tubing cutter was too big for a 360 deg. cut – like mine!) require some filing with a flat file to smooth the end surface. Then the inside of the line must be deburred to the original inside diameter. I did this with a sharp 1/4 inch drill bit. Be sure to remove ALL metal filings and/or shavings. I used compressed air for bench pieces, but for lines on the car I used a small wad of plumber’s putty followed by exposure to a strong magnet and a few “taps on the pipe.”

4) Make the bubble flares. Before flaring any ends, consider what needs to be installed on the line first, IE shrink wrap and the tube nut. A new tube nut was place on the new line segment for connection to a brass union and a bubble flare was made on the cut end. On the original factory line, my straightening efforts damaged the protective coating. So, before making the bubble flare, I installed a length of shrink wrap on the line, followed by a new tube nut.

5) Tighten the Tube Nuts. As with any fine thread connection, all fittings should be well aligned to permit hand threading. Once correctly threaded the nut should be wrenched tight until firm contact stops the nut. Then, the conventional wisdom is 1/6 more revolution should be enough.  What is certain is that the tube nuts should NOT be overtightened as this simply deforms the bubble flange resulting in leakage.

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<Marking for the Cut>                                          <Staging the Shrink Wrap and Tube Nut>

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<Set-up for Making the Bubble Flare>

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<Completed Bubble Flare>                                        <Factory (L) vs. Flare Tool (R) Comparison>

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<Completed Union>                                                    <Completed Rear Brake Line Connection>

Making the front brake lines were much more complicated regarding shaping the lines for a good fit that looks respectable.  Otherwise, the bending sequence, adding shrink wrap and tube nuts, and making the bubble flares remained the same.

One other thing I needed to do while I had work space, was to replace the #5 spark plug wire. It needed to be about 6 inches longer. I went to Summit Racing.com and bought the MSD 8.5mm wire replacement kit (MSD-34069) and plug wire boot kit (MSD-3304) for $32 and $10 respectively. With PA tax and $12 shipping, the total cost for me was $57.67. That is roughly 1/2 the price of an entire set!!  Ouch!!

I made it a point to photo document my effort on this because it is just difficult to find these details.  I realize every build is slightly different, but If you’re at this stage in your build and you have questions, feel free to reach out to me.

With the brake line work done and the coil packs relocated, I could now install my cleaned-up brake MC reservoir. I used new rubber grommets from Ian at 944Online, and it’s important to note that they should be installed in the MC first. I used a film coat of Sil-Glide for lubrication, positioned myself over the reservoir and pushed it into position. It took all my 180# self to make it happen.

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<New Brake Lines and #5 Plug Wire >                      <Completed Set-up Bird’s Eye View>


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<Completed Set-up Front View>

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<Current Engine Compartment Progress>


The next step… TPC Rad Kit installation.

Well folks I’m about to jump into the new radiator installation and I wanted to lay some of the ground work for task ahead.  So far, I have straighten and refurbished my factory radiator support cross-member and purchase the new and improved Texas Performance Concepts (TPC) all aluminum, 944 LS Dual Pass Radiator Kit, ($700 +T&S) and aluminum 944 Custom Dual Pass Fan Shroud ($75+T&S).

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<Reconditioned Radiator Mount / Lower Cross Member>

Thankfully, Kent at TPC has done all the “heavy lifting,” customizing the radiator design to address all the “fitment” requirements for the 944, plus suppling a complete installation kit with all new hoses AND hardware necessary for installation.  The newly designed custom laser-cut fan shroud came already mounted to the radiator and is fabricated with mounting holes to accommodate either the 944 NA or Turbo dual fans.

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<TPC Dual Pass Radiator with Custom Fan Shroud>          <New Hardware Provided>

I am not exactly sure yet where everything goes but I will figure it out as I go and document my way for posterity.  I have confidence in Kent’s expertise and that he has included everything I’ll need.  Frankly, this is the main reason TPC has been my main conversion supplier.  Product quality is great, parts fit correctly, and customer support is awesome!  It’s hard to put a price tag on the added planning, design and workmanship that goes into a TPC kit, but the ease of installation and a factory finished look make it all worth it!

More coming soon...

One of remaining efforts of this build is to configure the air intake. As noted in previous posts, the hood latch clearly must go to make room for a 4-inch dia. throttle-body intake hose which will traverse over the radiator. In addition, the cross-brace latch mount requires modification to access the proposed air filter location where an OTR filter box reportedly will fit quite nicely.

I have received some suggestions for an OTR intake box from folks that have gone down this road and I do appreciate that input, however I am always open to forum member ideas.  

The first thing I wanted to do was remove the front nose panel. This was simple enough once I found all the mounting fasteners! There are four (4) obvious Phillips head screws across the top, but there are also two (2) hidden 8 mm nuts, one hidden Phillips head screw, and one hidden 10 mm sheet metal bolt at each end, all accessible from the headlight pocket area.

To access the two hidden 8 mm nuts, the rubber molding headlight rest must be removed.  On my car there was nothing holding this molding in place, so I was able to just pry it out.  The hidden screw holds the panel to the cross brace and can be reached with a long shaft screwdriver.  Lastly, the hidden sheet metal bolt holds the panel to the fender. I was able to remove this bolt with a 1/4-inch drive ratchet and socket.

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<2 Hidden 8 mm Nuts>                                          < Hidden Headlight Screw>

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<Hidden 10 mm Sheet Metal Bolt>

Removal of the front panel provides clear access to the cross brace for the necessary modifications. I used my cordless Sawzall with a fine-tooth metal cutting blade to get the job done.  I covered the engine with a blanket to keep the flying metal bits off.

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<Front Panel Removed>  

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<Proposed Modification>                                                     <Executed Initial Cuts>

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<Completed Modification Front View>

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<Completed Modification 3/4 View>

I decided to remove the upper air deflector to provide better access when installing the new radiator and condenser.  Once the air box is configured, I’ll know if the deflector makes sense or not. There is a good amount of clean-up work needed and many areas only have primer… not to mention the bare metal cuts, which have all been ground smooth to the touch.  After a thorough prep, I’ll be laying down some Rust-oleum Cherry Red.  Lastly, I’ll put some door guard trim on the cut metal edges for a finished look.

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< Front View with Air Deflector Removed>

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< 3/4 View with Air Deflector Removed>

Getting access to the OTR airbox is going to take some ingenuity to come up with a removable or perhaps hinged front panel.  As always, I’m open to suggestions!!

The actual radiator installation is next…

OK, so I’m not quite ready to present installation of the TPC rad, but I did get some of the preliminary work done. Primarily, I got the stock fans ready to go and paired them up with the new laser cut TPC shroud adapter.

I started with a good clean-up, first using my pressure washer and then a good rub-down using a 50/50 water-based degreaser solution.  Below are the before pictures.

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<Factory Fans-Front>                                                               <Factory Fans-Back>

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<Fan Wire Connectors>                                                          <Fan Connector Polarity>

After clean-up, I took some time to paint the back of the fan motors black.  Then I moved on to testing the fan motors.  Each fan motor has a two-wire lead, one power (red and black) and one ground (brown). To make sure the leads get installed correctly, Porsche labeled the polarity on the motor lead connector. That bit of extra info was also helpful when testing the motors with my 12V battery pack.

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<Fan Motor Paint Prep>                                                   <Fan Motor Testing>

Both fan motors worked perfectly… All good to go!!

Next, I began the process of connecting the fan shroud to the new TPC shroud adapter.  The shroud adapter shipped attached to the rad so the first step was to remove the six (6) self-tapping screws that hold it on.  

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<Removing the TPC Shroud Adapter Screws>              <TPC Shroud Adapter Hole Alignment>

Note that the factory plastic fan shroud has six (6) rad mounting holes with the top three (3) slotted.  A test fit of the TPC shroud adapter on the factory fan shroud reveals good alignment of all holes. However, there is interference with the fan shroud center reinforcement rib, (top and bottom) and a modification is required. The typical distance from the edge of the TPC shroud adapter to the edge of each mounting hole is about 1/4 inch.  I allotted about 3/8 inch and used blue tape to mark the reinforcement rib segment to be removed.

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<Marking the Reinforcing Rib>                                  <Cutting the Reinforcing Rib>

A jab saw with a metal cutting blade did the trick.

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<Completed Rib Cut>                                                               <End Result>

A minor change I made from the TPC kit was the addition of a flat washer on the fan shroud side of the connection.  The 1/4” x 20 x 1/2" bolts are not long enough for both a flat washer and the supplied lock washer so I purchased new nylon locking nuts.

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<Factory Fans on TPC Shroud Adapter - Front View>

12/31/2021 Shroud Fastener Update: Before my test fit, I had second thoughts about using the nylon lock nuts on the 1/2” long mounting bolts.  The nylon was just barely engaged…plus when fully tightened against the TPC shroud adapter, the fan shroud plastic was deformed because of the thin gap where the factory threaded clips used to be.  This could potentially be a long-term point of failure.

With at least 3/4” of available space on the rad side of the TPC shroud adapter, a longer bolt can be used so I decided to buy 6 new M6-1.00 x 16mm bolts with matching serrated flange nuts.  This allowed me to use a flat washer under the bolt head and a second flat washer between the TPC shroud adapter and the fan shroud.  The second washer filled the gap so I was now able to properly tighten the mounting bolts WITHOUT any undo stress on the plastic fan shroud.

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<Nylon Lock Nut – Limited Engagement>                                 <Serrated Flange Nut>

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<Deformed Fan Shroud with 1/2” Bolt>                    <Undeformed Fan Shroud with 16mm Bolt>

I also discovered a minor interference between the new rad outlet hose (lower) and the factory fan shroud.  I marked the offending area with a Sharpie and cut/filed the flange as needed.

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<Fan Shroud / Outlet Hose Interference>                         <Modified Fan Shroud Flange>

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<Factory Fans on TPC Shroud Adapter and TPC Radiator>

Note in the photo above that I mounted the fan shroud assembly at the bottom of the radiator.  I did this because the 944S nose air intake is below the bumper which would add to the efficiency of the fans at low speed conditions.  Other 944 models have different primary air intake locations that are higher and would justify mounting the fan shroud at the top of the radiator.  The TPC shroud adapter is symmetrical allowing it to be mounted either way.

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<944S Air Intake Below Bumper>                                           <Hood “Almost” Closes>

BTW:  After removing the hood latch, I was better able to get a handle on my hood interference.   It almost shuts but the throttle body is hitting the hood reinforcement.

The fan/radiator assembly is now ready to install.  I compared the TPC custom radiator mount with my factory mount and discovered it to be just about 1/2” short. (25" between holes required)  This is not a big deal because of the way the TPC mount is made.  The extended depth end brackets can easily be bent out slightly to pick up 1/4” on each side.

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<TPC Radiator Support vs. Factory Radiator Support>

Tomorrow I’ll be doing a test fit to see just how the TPC rad fits in the allotted space.  The TPC radiator mount does not have provisions for lower grommets like the factory mount, but it is designed to fit and confine the custom radiator nicely, and a thin strip of rubber or neoprene would soften the support contact as needed.

Stay tuned!!

Reversing the deconstruction process, my 1st inclination was to install the TPC custom rad mount and then “shoehorn” the radiator/fan assembly into position. I didn’t measure the available space to accomplish this, considering that’s how the factory rad came out, but I can tell you…it’s TIGHT.

Forging ahead, I took the TPC rad mount out to the shed and bent the flanges outward slightly until the hole spacing matched the factory dimension, exactly 25 inches apart center-to-center. This was a minor effort and my large 4” vise made the job simple. No other tools required. Aluminum soft jaws prevented damage to the nice black powder coated finish.

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<Bending the TPC Rad Mount>
                       
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<Factory Radiator Support Connection>                               <TPC Radiator Support Connection>

The TPC rad support comes with new 8mm serrated flange hex head bolts, flat washers, and nuts, and fits exactly in the factory location. It is noticeably wider than the factory support to accommodate the custom TPC radiator. Lower rubber grommets are not used. I elected to mount the TPC rad support just like the factory support.

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<TPC Rad Mount Installed>                                    <Radiator/Fan Assembly Clearance>

The new fan/radiator assembly weighs 22.8 lbs. and is manageable to install as a unit from under the car…especially for me with car elevated on my MaxJax (please don’t hate me!). With the assembly in hand and being very careful not to ding up the exposed radiator veins, I proceeded to angle the assembly up into position and rest it on the TPC radiator mount…NOT!

FIRST FAIL: There is insufficient space to install the fan/radiator assembly this way.  Checking the numbers like I should have to begin with, the TPC rad is 2-1/2” wide vs the factory rad at 2-1/8” wide. That’s 3/8” more width plus the TPC shroud adapter which is an additional 3/4.” Adding ~3” for the factory fan shroud and the total assembly is ~ 6-1/4" vs the factory assembly of only 5-1/8.” Not only is the new assembly 1-1/8” larger, the available installation window is reduced by the wider TPC support mount which is 3-1/2” wide vs the factory support at only 3” wide (not including the belly pan mounting tabs). With the LS installation window at about 5,” clearly the math also proves my reverse deconstruction logic is not the way.

PLAN B: I consulted Kent at TPC with my dilemma and he suggested installing the fan/radiator assembly into position before the rad support, holding it in place with temporary ties, and then bolting the rad support into position from the bottom.

In my first attempt at Plan B, I raised the assembly incrementally and tied it in place with packing string. Upon attempting to bolt on the rad support, I soon realized the radiator body occupies the available space to install the nuts on the bolts. Duh…too excited, I guess! Back down with the assembly.
The simple solution was to reverse the orientation of the bolts and insert them shaft down. This puts to good use the serrated hex head flange.

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<Support Boxes>                                               <Inverted Connection Bolts>

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<Raising the Assembly Top View>                                            <Raised Assembly Front View>

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<Factory Grommet Modification>                                          <Grommet Set in TPC Rad Dog Ears>

In my second attempt, I modified my lower rad mount grommets by cutting off the extension that fits in the factory rad support, and inserted the grommets in the raised dog ears installed on the TPC rad. I raised the assembly again, positioned the assembly as high as possible, and attempted to mount the radiator support. The target bolts are loose in the body mount which makes aligning the rad support holes a bit tricky. I used my floor jack and a length of 4x4 to hold the rad support in position. I slowly raised the support with the jack so I could align the support holes with the bolts and install the nuts…NOT!

SECOND FAIL:The TPC dog ears prevented me from raising the rad assemble far enough to connect the rad support bolts. My immediate reaction was to apply more force to the jack. This worked somewhat but I was still short by about 1/2" from fully tighten the support mounting bolts. When the jack began to lift the car, I knew there was substantial interference. After examination, some portions of the driver’s side mounting frame had insufficient clearance and were identified as the restriction. Even more concerning, the fan shroud motor brackets where now in full contact with the harmonic balancer! Back down with the assembly.

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<Rad Support Short Connection>                                 <Dog Ear Interference>

PLAN C: The TPC dog ears and grommets where forcing the radiator back toward the engine, leaving about a 1/2” space between the front of the rad and the mounting frame. In addition, the lateral clearance available for the radiator at the top is the exact same dimension as the radiator itself. The solution was two-fold, 1) remove the dog ears, and 2) sheet metal modification of the mounting frame to gain ~1/4” clearance.

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< Removing the Dog Ears >                               < Completed Dog Ear Removal >

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<Mounting Frame with Contact Scars>                                    <Modified Mounting Frame>

In addition to making the above major modifications, I also moved the grommet on the passenger side from the factory location toward center to permit the top of the rad to come forward into the proper position. I also made minor clearance modifications anywhere the radiator contacted the mounting frame.

SUCCESS: I raised the rad assembly into position…one more time. Everything fit…YAY, but I still needed to use a large C-Clamp on the top passenger side corner of the rad to gently pull it completely forward. Once in place, I fully tightening the support mounting bolts and the clamping force on the grommets is holding the assembly firm.  

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<Completed Fan/Radiator Installation>

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<Passenger Side Top>                                                                 <Driver’s Side Top>
         
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<Passenger Side Support Connection>                                <Driver’s Side Support Connection>

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<Completed Installation with 3/16” Clearance>

With only 3/16” of clearance between the fan motor support bracing and the harmonic balancer, I’m planning to fabricate a pair of aluminum clamps for a positive bolted connection. Update on that soon.

1/5/2022 UPDATE:  After some head scratching, mounting an effective bracket was going to be a bit more involved than I thought. Without a positive support bracing, the 3/16” clearance was really making me nervous.  So, based on some input from Bob – Hotrodz of Dallas, via Kent at TPC, I elected to “trim” the upper fan motor mounting brackets to pick up more clearance.  Miraculously, a long blade on my cordless, variable speed, Sawzall was enough to reach the cut area and made the job easy.  I used a metal cutting blade for a smooth cut and took my time.

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<Proposed Cut on Shroud Motor Brace>                   <Completed Cut on Shroud Motor Brace>

The above photos are of the driver’s side and I performed the same operation on the passenger side.  I now have a minimum of 3/8” clearance!  YAY!!

I began installing the remaining fitting for the overflow tank return line and the radiator temperature sensor and soon realized that there is NO ROOM FOR TOOLS and the fittings cannot be tightened…at least not with any tools I own.  I marked the desired orientation of the return fitting and pulled out the assembly one more time!!

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<Marked Position of the Return Fitting>                        <Installed and Tightened Fittings>
   
All fitting threads were coated with liquid PTFE sealant and easily installed with unlimited space for my 12” crescent wrench! I opted to install my factory temperature sending unit just in case I needed it.  The TPC kit comes with a delete plug if the temp sensor is not needed in your setup.  Similarly, the TPC kit gives you options for a straight or 45-degree fitting arrangement for the overflow hose and the return line.  As you can see in the pic, I opted for the 45-degree return line fitting.  

NOTE: With the PTFE sealant in play, the fittings only need be “tight.”  For the return line sensor, after hand tightening, I used my crescent wrench to turn it approximately 3/4 turn to the 4:00 position I had marked.  The last think you want to do is overtighten these brass fittings and strip or crack the aluminum.

While I had the rad on the bench, I cleaned up my cuts on the shroud motor bracing using a small grinding stone, so they were nice and smooth. For the reinstall, I followed the aforesaid procedure including use of the C-Clamp.  However, I decided to move the factory grommet on the passenger side back into the original position.  This resulted in a super secure fit once the rad support bolts were tightened.  Recall that there is just enough weld ridge left from the dog ears to prevent the grommets from sliding forward or back on the rad.

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<Cleaned-up Shroud Motor Bracing Cut>                    <C-Clamp Installation Assist>

With the rad reinstalled, I lubed up the new TPC radiator hoses with a light coat of Sil-Glyde, positioned all the SS screw clamps for easy future accessibility, and installed the hoses.   Note that I temporarily reinstalled the headlight lift motor and drive mechanism to be sure the upper hose and clamps were in the ideal position. Also, the upper hose looks reversible but it is not and Kent at TPC was kind enough to label each end, “rad” & “LS,” just to make things even easier.

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<Installation Clue from TPC>                                         <Top Radiator Hose>

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<Bottom Radiator Hose>                                                 <Underside View>

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<Completed Reinstall>                                        <Installed TPC Radiator Fittings>

In the above “Completed Reinstall” pic, you may have noticed that the nearside fan shroud has warped.  This created a 3/16” gap between the factory shroud and the TPC shroud adapter.  There was similar warpage on the bottom.  There should be NO GAPS as this works against the fan vacuum pulling air through the rad.  For me the solution was filling the void with a hand-rolled bead of my trusty black windshield sealant.

UPDATE 6-27-2022

I finally got all the secondary radiator hoses sorted out.  There is one big change from the prior pics in this post, and that is the use of the TPC 34 deg. brass angle fitting for the overflow and steam vent hose connection.  I also ended up bending a piece of aluminum hard line for the steam vent tube connection to the overflow hose Tee.  I just couldn't get flexible hose to fit neatly and with the necessary clearance between moving parts.

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<Final Installation of the Filler, Overflow, and Steam Vent Hoses>

Next up, installing the new condenser and dryer…

The TPC custom Condenser and Drier combo are UAC units selected and tested for performance by TPC.  Both are replacement units suitable for the 944, however the condenser inlet and outlet connections are both on the passenger side vs the driver’s side, like the factory Porsche unit.  

TPC Custom UAC Condenser and Drier: $95 + S&H +Tax

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<UAC Condenser>                                                                         <UAC Drier>
   
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<UAC Condenser Coils>                                                    <Factory Porsche Condenser Coils>

One obvious difference between my factory condenser and the UAC unit is the coil configuration.  The UAC unit has a single row of rectangular coils while the factory unit has two rows of circular tubing.  I contacted TPC about this as I was concerned that the UAC unit would not provide equal performance and learned from Kent why he labels the package “custom.”  He assured me the components in his kits are selected after being fully tested in his on-site “mule” cars for fit and performance.  That works for me!!

Note in the photo above of the factory condenser that the lower mounting slots in the UAC condenser frame are smaller than those in the factory frame.   Consequently, they are too small to accept the factory Porsche mounting hardware.  This required a minor modification using my rat-tail file to enlarge the end of the slot to a 0.70-inch diameter as shown in the photos below.

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<Proposed UAC Mounting Frame Mod>                                <Completed Modification >

I also spent some time refurbishing the factory mounting hardware.  The rubber components were all in good shape.  The metal components had some corrosion so I soaked them in vinegar overnight, prepped them, and sprayed them with flat black paint.  Each lower mounting hardware assembly is comprised of a slotted rubber grommet, a steel tube center spacer, two large flat washers, and an M6-1.00 x 25mm bolt.  For security I added a lock washer and used a new 30mm flange bolts for ease of installation.

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<DS Upper Mount Rubber Sleeve In-Place>                           <Lower Mounting Hardware>
       
Care must be taken when using a longer mounting bolt because of the larger TPC rad.  The rad measures 25 inches out-to-out and the mounting holes measure 24-7/8 inches center-to-center.  There is just enough room to install the bolts without hitting the rad, but the condenser must be perfectly centered, and the bolts should be run in by hand to be sure the embedded nut behind the cross-frame is positioned outside the rad body.  Note in the photo below that you can see the rad body behind the mounting nut when it is incorrectly shifted toward center.

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<Cross-Frame Condenser Mounting Nut>                            <Frame Installed in Upper Mount>


Installation Steps:
• Slide the mounting nuts outward until the rad body cannot be seen through the nuts.
• Assemble the lower grommet assemblies in the mounting frame, complete with bolts.
• Insert the condenser frame into the upper mounts.
• Line up the lower mounting assemblies with the mounting nuts.
• Hand start the mounting bolts and run them in by hand to be sure the rad body is not offering any resistance.
• Wrench tighten to 18 ft-lbs.

         
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<Lower PS Mounting Bolt Installed>                     <1-1/8 In. Gap Between Rad and Condenser>

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<Completed Installation Bottom View>


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<Completed Installation Top View>


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<Factory Drier and High/Low Switch>

Next up, relocating and installing the new drier…

Kent is not quite correct in the performance of the a/c with the new components. It will actually blow a lot colder now. The new style compressor and condenser are way more efficient.

Hotrodz of Dallas wrote:Kent is not quite correct in the performance of the a/c with the new components. It will actually blow a lot colder now. The new style compressor and condenser are way more efficient.

Bob, my bad!  Kent did say the AC was "super cold" with the new set-up.  I never had a fully operational factory system to compare performance but as you noted, it makes sense that the modern AC technology performs better.

Way back when I got my car, the AC didn't work at all, apparently due to a leak.  I proceeded to have it converted to R-134 with the AC tech fixing the leak and blending the Freon for optimal performance...I don't recall the formulation.  It seemed to work well, blowing 68 deg. at the vent as I recall.

So while we're on the subject, do you have any recommendations on building new AC lines without chopping up my old ones?  IE: reusable ends and conversion pieces for the firewall "push to fit" O-ring connections. New factory AC line segments are extremely pricey and I'm sure there are folks out there doing restorations that are potential buyers.

I did find a local shop that can build me anything I need...but that would be after I got the car on the road.

Thanks Bob!

The ac lines can be a problem. As long as you have the original lines at the firewall, then the ac shop should be able to utilize the part that bolts to the evaporator ports. They can cut the ends off and weld on the correct hose fittings for you. Then build new lines from there to the compressor and drier. All hoses would then be on the passenger side with the drier mounted to the right side of the radiator on the frame. On a couple of cars, I spliced into the existing hoses on the driver side and then ran them to the passenger side. Only do this if your hoses are in excellent condition, which is unlikely. I looked, but I don't have any pics of the lines at the firewall.
I've talked to a supplier that makes custom fittings and adapters about making firewall fittings for the 944 LS. They would do it if I placed a minimum order of $1000 worth of the fittings. I'm not willing to do that at this moment.

Hotrodz of Dallas wrote:... I looked, but I don't have any pics of the lines at the firewall.
I've talked to a supplier that makes custom fittings and adapters about making firewall fittings for the 944 LS. They would do it if I placed a minimum order of $1000 worth of the fittings. I'm not willing to do that at this moment.

Bob, I would be happy to capture any pics you might need.  I have all my factory hoses and the firewall evaporator ports are still mostly accessible.  Below are a few pics I already have.

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