Some have thought it, no one's done it...Northstar

Anyone fairly familiar with the Cadillac Northstar engine series? They seem to be fairly compact, especially for a DOHC motor, and are not much heavier than an LS motor. They do have a bit of techy neatness in the DOHC arrangement and VVT on some later models. Additionally, they are shorter lengthwise than an LS motor as they are designed to be FWD mostly (although there are RWD/AWD versions).

From rough measurements and also from some online searching it should be only about a half inch wider than a dressed LS motor so it should likely fit...I can buy them all day long at the local boneyard for $200 apiece...

Thoughts?

They have a nice sound, I heard one leaving a lot at WOT and was suprised to see a Cadillac.

Isn't that a BOP bellhousing engine?
Get the BH dims posted.

Would the heads even clear the steering shaft?

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According to the 5th post, the BH's are all over the place, just need to find one and measure it.

There is a guy here in OKC that has stabbed that engine into a few Fieros(i've seen one personally). If it can fit that contraption, then the 944 bay is a cakewalk. It's not the steering shaft that is the worry but the strut towers and as I have stated before they can be cut and re-boxed (but I doubt that is the case even as MatthewB has stabbed a 4.6 modular Ford and it fit). I have drilled and welded to the towers and it is strong sheetmetal. If you need a TT adapter plate made for it, holla. We'll Getter done.

Here's the Northstar Specs & Dims....
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Here's one BH solution.....
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More Dims comparison...Northstar, LT1, LS1....
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The bellhousing on the Northstar 4.0l and 4.6l are the 60* v6 housing. You can use any of them, you have gindout some webbing near the top of the valley for the starter and one of the bolt holes doesnt line up. The 3800 also uses the same bellhousing. So with that in mind the new 3800swap the admin is doing could do a northstar.

Problems I see with the Northstar would be size! Its fricken huge and the rough dimensions I found since I no longer have one of these engines showed it to be a bit large for the bay. Second would be the water log at the rear of the engine. The Intake is flippable so thats not an issue at all. I really am unsure if its the same size or larger than the ford Dohc.

IIRC the newer Nortstar blocks have the water pump on the front. The dims in the previous post show the northstar width 2 more inches wider than the LS1, so it would fit between the 944 towers. I also am eyeing a totally different bellhousing that can also bolt to the Northstar along with the GM 60deg BH i4,5,6, AND there is another BH that the adapter plate would fit all GM V8's......

Quote""""""""this is actually a good benefit for me, the new northstar has 60 more hp over the older model , it also has a front mounted waterpump, better motor mounts, smaller oil pan, and VVT and coil on plug. its also alot more refined and has a bunch of little goodies that make it the right choice. i could go one step further and buy a V series engine loose .2 liters and gain 80 more over the already impressive 360hp with a sweet ass supercharger""""""

OLD northstar L37----28" x 26" x 31" (W x H x L)
NEW northstar---28" x 24.5" x 26.5" (non-V motor)
LT1 ---------------24.75" x 24" x 27.5",
LS1----------------26" x 25" x 28"

I did a *rough* measurement at the boneyard yesterday and should be at most 28 inches wide, the valvecovers are wider than the exhaust. It is a short engine, I found an SLS with the front end taken off and looking straight at the profile of the motor it looks actually shorter lengthwise than a 944 motor.

Other measurements I have found show it to be 27" wide, if I have a day to commit I could always just go to the boneyard and pull one from any of the multiple Caddy's they have.

Someone pointed out the waterpump location; on the RWD/AWD versions the waterpump is on the front of the engine, in the FWD versions it is driven by a narrow belt on the back of the motor above the transaxle. I think if I got a FWD version I could simply block off the hole for the waterpump and run an electric pump elsewhere, I'd have to study the coolant flow of the motor though.

I could always just go to the boneyard and pull one from any of the multiple Caddy's they have.

Theres a reason why you CAN do that. These engines are notorious for blown head gaskets. I have a 1999 deville 4.6L in my driveway right now waiting for one. Now normally I dont mind such a thing but the biggest problem is that when you pull the head, the aluminum thread come out with the steel head bolts. Then you have to install time-serts to fix that.

ORLY?

have you had any other issues with it? ive heard and read that they are very well made, very reliable. certainly wouldnt want a hg to blow, is there a common problem that causes the blowout?

My local machine shop won't even work on these motors.

Theres a reason why you CAN do that. These engines are notorious for blown head gaskets. I have a 1999 deville 4.6L in my driveway right now waiting for one. Now normally I dont mind such a thing but the biggest problem is that when you pull the head, the aluminum thread come out with the steel head bolts. Then you have to install time-serts to fix that.

Co'mon, just search the net. The reason for this is you used the wrong coolant.

Just like it is the same engine as the ZR1.....and that it was used in the Escalade (not the LS based engine)

Or as one cam grinder told me that he wouldn't warranty his cams unless you used Pennsylvania crude oil and that synthetic would destroy them.

ZDDP.... Because Big Brother doesn't like Zinc in motor oils. They would rather you destroy your cams/lifters then create a little pollution.

what seems to be the cause of the hg failures? warping, overheating, a design flaw?

Yeah what's the dealy? Was it the head bolts breaking in the block? I thought I read that the 05-up newer Northstars had a wider head sealing surface but not sure. Edumacate us!

with some reading, apparently the head bolts get loose with age because the steel sleeves pressed into the block loosen somehow. after a bunch of complaints GM used longer bolts with coarser thread pitch to try to address it

the solution is to stud the block, found a company that will sell the full stud kit for $550CDN or will stud the motor and reseal the engine for about $2000CDN...interesting.

time to wait for the exchange rate to drop

That damn metal expansion differential stumped them again. These GM guys have engineering degrees?

1. heat cycling the aluminum block around the steel bolt threads while the aluminum heads/block are expanding causing the bolts to stretch-and-contract enough to weaken the aluminum threads eventually stripping them enough to allow coolant to pass around a pretty poorly designed head gasket and into the threads.

2. Poorly designed headgasket with steel fire rings that heat cycle and fracture allowing an access for combustion pressure and further heat cycles to widen the fracture to the point coolant can pass through to the combustion chamber and the head bolt threads and, as well, causing acidic coolant that further aids in the galvanic reaction between the steel bolt threads and aluminum bore.....

A theory is that when the headgasket fails, whether due to 1 then 2 or 2 then 1 or both, the coolant enters the head bolt threads. Now, the steel bolt and the aluminum block, being dissimilar metals, cause an initiating and sustaining galvanic action and thus corrosion of the already weakened threads. It is here inside the aluminum threaded bore and between the steel bolt threads that coolant acts as the electrolyte in the reaction; weakening the aluminum and chewing it away. In the presence of the coolant electrolyte (serving as the conductive material), a current will flow from the aluminum block (the large anode) to the steel bolts (the cathode) and the anode will be degraded. This all leads to weakened torque on the head bolts allowing the head to separate from the gasket and there you go.

Personally, I believe its the lack of sufficient cooling at the heads and immediate area as well as the design of the coolant passages at head deck and head that causes the failure. It would seem that once the coolant looses any heat exchange capacity (unmaintenanced coolant system), those areas of the engine just overheats. Thermal cycling occurs, stresses the bolts and fire rings until something gives.

Regardless, these engines be blowin' headgaskets to the point GM just said "the hell with 'em, lets just start throwing the LS engine into the caddys"....and thats what happened. GM has signed the northstars release papers and as of this year, no more northstars are to be manufactured. All replaced with LS variants....and im sure the good old GM 3800 V6's (and variants) will continue forward....good engines.

Hmmm, so if doing inserts or the stud kit, you'd want to dab on some high temp anti-seize to the threads.....

So are the Northstar head bolt bores drilled into the coolant passages as well, or corrosion occurs after the headgasket blows and leaks into them?

Edit: My 5.3 swap got the exhaust header bolts treated with this same HT antiseize.....
I've done quite a few head swaps and header installs, removals on alot of air cooled bikes and a few cars with this stuff. My current bike I have to remove the headers for an oil change and the exhaust bolts come right out without seizing.....and the headers glow cherry red the way I ride it LOL.....

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with regards to "lets just LS the caddies" i imagine that is a combination of factors...
1) the northstar design is 20 years old now with no real changes aside from RWD modification and VVT. power output has remained fairly constant in the last 20 years
2) warranty issues with headgasket failures
3) LS engines are 7 years in production and probably 10 in design younger than the N*, also slightly lighter weight. plus since VVT has been figured out with single-cam OHV engines the fancy DOHC witchcraft can be done away with, removing complexity and increasing reliability
4) caddy's are heavy, they need torque to move without using much gas, and a 2-valve v8 makes more lowspeed torque better than a 4-valve

I would still like to see one shoved in the 944. And you're right, with the new VVT and DOD systems on the LS pushrod engines, the Gas mileage #'s have increased on the heavier vehicles.....

it is something i will continue to investigate the possibilities of. can you make an adapter for an S10 bellhousing for the 944TT? lol

Get me the BH dims. If it is the 60 degree BH pattern, my next plate design will bolt to a BH that does.

Gotta run and get me a Sammich.......nice thing about the iron blocks is key it and punch the throttle.