Engine Swap...Cadillac N*?
I've always been a bigger is better kinda guy...but this N* is a helluva engine at just 279cid. And I'm thinking there's room for improvement. The usual suspects...cams, head work, TB work, ECM tuning, exhaust...and it's light!
I know it has head gasket issues but those would be easy enough to deal with under a clam shell hood...
So, has anyone done it? Can it be done?
If I where to do a swap for performance it would be an LS motor not a caddy. I did the LT1 swap in my 84 and it is a lot of work but with proper planing anything can be done, keep in mind that the newer gen motors require you use thier assy bracets or customise a set to fit. Its hell to get a motor inplace only to find you can't get the P/S, alt and A/C to work.
If I where to do a swap for performance it would be an LS motor not a caddy. I did the LT1 swap in my 84 and it is a lot of work but with proper planing anything can be done, keep in mind that the newer gen motors require you use thier assy bracets or customise a set to fit. Its hell to get a motor inplace only to find you can't get the P/S, alt and A/C to work.
If you're going to do a major swap like that, I've go with the new LS motors...maybe even wait for the new LS7 crate motor to be released!





If youre going to do that, put an LT5 in it. Northstar is based on it's technology anyway.
Just my .02


Not enough low end torque to make it practical... I've had 2 NS powered Caddys and while they're good for daily driver duty, I wouldn't want it in my C4...
Oh, and there are 2 variants of the NS (3 now if you count the new VVT NS), I was only talking older doner cars... The weaker 275 HP motor has more low end torque than the 300 HP motor... I've had both and miss the weaker motor in my last non ETC Eldorado...
The performance that I get from my Eldo is most impressive given the size of the engine (and it's associated restraints-intake/exhaust) and the weight of the car.
Engine swaps are problematical to begin with...that's not the point...at least for me. I enjoy that sort of problem solving thing.
I'm thinking along the lines of the finished product and the "ooo-ahhh" value when I open the hood. Not to mention the weight savings and how that would affect the handling characteristics of the C4.
So...opinions aside has anyone ever heard of such a swap? I've read about a few guys swapping in the Buick 3800 V6 turbo into a C4...I like that kind of exotic combination.
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Here are the big things I can think of
Wiring, you will need a northstar engine harness and a good wiring diagram and some idea of what you are doing to intigrate the harness with the C4's existing harness (It was a lot of wiring on the LT1)
Motor Mounts, The LT1 used stock mounts but you may need to fab adapter plates.
Assy's. This is a big one. With the LT1 I was able to just add a LT1 C4's brackets and assy's but you will have to hope the northstars assy's fit or you will be into some custom fab work, If you want A/C, as I did, you will need to find a local shop and have custom A/C lines fabed (It was $150 for mine), same with the P/S lines.
Radiator, no big deal for the northstar but I needed a steam vent tube for the LT1.
Exhaust, could be another interesting one with the northstar, may need custom exhaust and that might get expensive.
Tuning the ECM, I have no idea of what is available for the northstar but If it is OBDII it is going to get a little trickey if you don't install all of the emisions or if you do any HP mods.
VATS, could be with ECM but listed it seperate, If the Caddy, uses any form of VATS you will need to find a way to disable it
Trany, could be a show stoper or at least complicated Fab work, What bolt patern does the STS Hydra-Matic 4T80-E use? If it is the same as the standard GM trany then you will just need to find the proper FW/Flexplate for your application, if it is available. If the bolt patern is diferent you will have to fab an adapter plate.
Good luck











