944-LT1 LS3 Conversion

Hai guys!

Been doing stuff. Sold my LT1 and used the money to buy the new LS3 engine! I know, I know, im a traitor to my kind. BUT, I was done with the LT and there was nothing left to master there. So, Im gonna go after the LS conversions now.

Im going to re-use my bellhousing with the LS3 and it fits nicely. Ill also re-use the radiator and motor mounts. But will not be able to re-use the RH mid-length headers, RH oil pan, RH saddle mount, RH LT accessory bracket and RH pilot bearing.

So heres some pics!

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My god thats beautiful!!!

Do you have any upgrade plans for the LS3? They can be made to put out some pretty hefty HP numbers, with a small amount of work.

Please post all the bloody details!!

Thanks! So far, I just plan on some headers (weld-up kit) and a tune. Should see 440-450 rwhp or so says the corvette/camaro folks that have had dyno time after a tune with complete stock engine. I guess the rumor is that the factory de-tuned it a bit. So after a simple tune, it makes the above. I dont know if I can believe all that cause its just forum talk. But after 5-8 people posted their paperwork....I guess its true!


Question again, what to do about this drive by wire pedal they gave me??? Has anyone done a drive by wire pedal and is the connector a part of the engine harness or body harness? It came with the engine but was just kinda sitting on the pallet.

944-LT1 wrote:...Question again, what to do about this drive by wire pedal they gave me??? Has anyone done a drive by wire pedal and is the connector a part of the engine harness or body harness? It came with the engine but was just kinda sitting on the pallet.

Pat (skywalker) has the drive by wire setup...

Nice, BTW!

....Greedy
Man, that looks like it was designed just for that bay.
I saw a drive by wire pedal from a newer truck basically bolted into the body of a jeep.
Good find BTW

check out the ls engine schematics for stuff about that drive by wire setup, I think it plug into another module?

you came to the dark side :p

About the drive by wire setup...... I had an idea with that.....

Do you think it would be possible to program in something to the PCM for a "valet" mode (Though for me, it would be "wife" mode)?

I want to hit a switch and have like 1/4 throttle be the maximum the engine would get. I don't want the valet guy having access to 450hp in MY car.... and I don't want my wife bashing a tree when she goes to check the mail.... but when I'm driving, I could hit said switch and get full throttle....It would obviously only work with the drive by wire setup. You would floor the pedal, but the throttle plate would only move to 1/4 throttle at the most.

Smell what I'm cookin???

I dunno about the coding/pcm side of things, but if it runs off a potentiometer you might be able to put in a diode or something of that nature to clamp the input down when you flip the switch, Id have to look at the setup though

944-LS3, I mean LT-1,
Take notes. This is the next step for LT1 owners. A limited production run and hence aftermarket support makes the LT1 less desireable as time goes by. Sorry guys, truth hurts! It would be great to know the parts and procedures required to make the swap. Right now I'm working on stuffing an LS1 in my Miata but I'll get back to my Porsche in due time.

Take notes. This is the next step for LT1 owners.

It happened like this:
My uncle wanted to have a non-numbers matching V8 rebuilt for his 1966 corvette but the block needed mass amounts of work as it was frozen at each piston. He also wanted (since that block was not original) to have an engine that had decent MPG and power. I talked to him about the LS engines but he damned the thought immediately. Then he popped his head into my bay and saw my LT1. He wanted my engine because it was a direct bolt in so much so that it still retained the threaded hole near the oil filter casting that allows a mechanical clutch system to be retained. My LT1 had everything new on it as well it onloy had about 55K on the clock. He bought it and my 44 was then engineless. So, after checking around, i was making a deal with a guy in LA for an LS7 short-block. Well, after reading GM's engine forecast which said that the LS3 would be the mainstay (or simply the new 350) and all other engines would be phased out, I struck a deal with some fellers in WI for the LS3 which was in a 2009 vette accident. We talked about price for a few days and got him to bring it down to 5300 complete with pedal!

The biggest part was that I had already conqured the LT conversion and wanted a new challenge. The other reasons were that I wanted something that no one else had yet....I saw a few LS2's and crap loads of LS1/6's but no LS3 yet. So.....LS3!

Fair to say first LS3 944 or Porsche for that matter?!?!?

I will keep notes for the LT1 to LS conversion!

So far, im running into the same problem johnny and XS ran into on the old board in that as mounted to the TT, the motor mount uprights are ahead of the motor mount isolators of the engine. Im using the RH uprights as ordered for the LT but thought they were the same for the LS conversion.

I ordered a set of motor mount adapter plates from the bay and post pics of how far there off. May have to cut these mounts up and re-weld them.

DO NEED THE PILOT BEARING ADAPTER IF ANYONE HAS AN EXTRA THEY WANNA SELL!!!!

Another problem is the flywheel. Ive been searching but cant really confirm if theres a 10.5" flywheel for the LS3 or better yet if I can fit an 11" flywheel in the RH LT bellhousing.

the DBW pedal, ive found out, is gonna take some funky wiring.

944-LT1 wrote:...DO NEED THE PILOT BEARING ADAPTER IF ANYONE HAS AN EXTRA THEY WANNA SELL!!!!

Another problem is the flywheel. Ive been searching but cant really confirm if theres a 10.5" flywheel for the LS3 or better yet if I can fit an 11" flywheel in the RH LT bellhousing...

Mcleod sells a "conversion" flywheel, but it's ~ $450.

[From our Wiki...]

McLeod LSX conversion flywheel #460535 (Summit Racing – allows use of early non-metric SBC clutch components)

No 10.5" flywheel for the LS...remember, the flange on the LS is metric vs. SAE on the SBC/LT.

S.O.L. on the RH BH too, dude...unless you use the Mcleod flywheel.

xschop posted some engine mount plates...worked on the 5.3L.
[You must be registered and logged in to see this link.] < click on this
.

The Plates work like a charm with the LT mount dimensions. The Moroso pan has plenty of clearance to shift the LS engine around with these plates. Pilot bearing adapters I can make to custom thicknesses, but the real trick is to get a thicker Pilot bearing if your shaft doesn't initially engage deep enough. I am running a 15x35x14 and it is perfect. RH "Cast" BH I can't comment on. I wouldn't trust the crank concentricity unless I put it up on the Block and used dial indication equip. But if it didn't burn your TT shaft when you had it on the LT engine, then go for it. You should double check what thickness Pilot Bearing Adapter you need if you do reuse the Cast BH, Because the PB adapter for the LS engine using the C5 BH is 1.00" thick because of the 5.80" C5 BH depth.

Whaaaaaaa

Crap. Well, I guess I have a BH to sell as well.

Thanks.

1) What is the Cast BH depth (Block face to TT face)?
2) What is the Block face to crank end measurement on that LS3?

The Plates work like a charm with the LT mount dimensions. The Moroso pan has plenty of clearance to shift the LS engine around with these plates. Pilot bearing adapters I can make to custom thicknesses, but the real trick is to get a thicker Pilot bearing if your shaft doesn't initially engage deep enough. I am running a 15x35x14 and it is perfect. RH "Cast" BH I can't comment on. I wouldn't trust the crank concentricity unless I put it up on the Block and used dial indication equip. But if it didn't burn your TT shaft when you had it on the LT engine, then go for it. You should double check what thickness Pilot Bearing Adapter you need if you do reuse the Cast BH, Because the PB adapter for the LS engine using the C5 BH is 1.00" thick because of the 5.80" C5 BH depth.

1) What is the Cast BH depth (Block face to TT face)?
2) What is the Block face to crank end measurement on that LS3?

Ill pull the engine back out tonight and get those. .....it fit so well too....

Does that cast BH have an internal TO bearing like the C5?

No. its external 1985 corvette style slave.

The engine is back out and the depth of the RH cast housing is 6.350" exact.

The LS3 block flange to crank face where the flywheel would set is 0.315" roughly. Cant easily get a real good measurement there. But its between 0.310" and 0.320" so I averaged it.

I tried to fit the LS3 A6 flexplate (168 tooth and 14-1/8" diameter) into the RH bellhousing....absolutely no go. Why the hell RH didnt cast it for a 168t i'll never know. PORH FRH SRH

"944-LS3", save some gas money, dude:

1] Eekbay C5 BH, ~ $100
2] Self-mod the LS harness
3] Do some "trading"...[PM me - I need an LT flywheel, if you still have it...]
4] Read this...LS Engine History
5] Don't sweat the small $#**...you have the first 944-dedicated LS3

*#4 is more of a reference for everyone else, MK.

EDIT:
6] Read this also...(the LS1 PCM is compatible with a few mods...)
2001 Chevy Camaro Z28 LS3 Dual Disc Clutch & Wiring Harness Install - Fourth-Gen Gen IV

- and from LS1Tech.com...
Flywheel and TO bearing info
.

Oh man I dont have the flywheel anymore. But im all up for trades. Thanks for the links. Good stuff. How do you find all this stuff!

Ill get some pics up but for now I have:
- RH cast bellhousing assy. (with a new bearing retainer, bearing, fork and new slave assy.)
- RH accessory bracket assy. (shortened to clear hood by RH with AC delete pulley assy. and idler) I can include a rebuilt PS pump as well.
- RH pilot bearing adapter (with needle bearing inside can pull out [never tore up my shaft tip])
- RH oil pan (been painted on sides with POR15 "aluminum" engine enamel never leaked)
- RH (sanderson) CC2 and CC90 headers (used and cracks re-welded)
- RH saddle mount style motor mounts (repainted!)
- RH 10.5" clutch disc (used but lots of life in it)
- Custom Kevlar clutch disc for Porsche 944 4 cylinder
- Factory GM O2 sensor extension harnesses
- New GM optispark cap and rotor
- LT1 water pump cores (2 of them one is gutted for e- pump conversion)

Again, up for trades for stuff thatll work with an LS3 conversion!!!!

Edit: Heres some pics of things I could wrangle together...
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944-LT1 wrote:RH oil pan (been painted on sides with POR15 "aluminum" engine enamel never leaked)

I may be interested in that...decide what it's worth to ya, and show me a pic.
Also, the LS2 / LS3 / LS7 share a flywheel.

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xschop posted some engine mount plates...worked on the 5.3L.
Plates < click on this

Hey...I bought mine from carshopinc as well. They didnt say if they were 1/2" thick though.

gt1scca wrote:

944-LT1 wrote:RH oil pan (been painted on sides with POR15 "aluminum" engine enamel never leaked)

I may be interested in that...decide what it's worth to ya, and show me a pic.
Also, the LS2 / LS3 / LS7 share a flywheel.

Yeah I saw that from the links you gave me. Sadly that flywheel wont fit my cast bellhousing.

Looks like Matt (msmoorenburg) is first in line for the pan if he doesnt want it then its Alien.

Greg, theres gotta be something you want!!! I have an LT1 harness?!?! If nothing else, you can french braid the wires!!

Probably .25".

BTW, S-can that bearing!

^^^ [That reminds me...did the TT bearings check out OK?
What the doose on dat?]

What's it worth to ya, WITH the o2 ext.? PM
.