S54 E30 M3
 

I started this process a few weeks ago and figured I'd log some updates here.

After the long restoration on the M3, I ended up throwing in the S50US out of the yellow car in order to get it driving. This had the advantage of being a very cheap, easy swap that I could do basically for the cost of building an exhaust, and providing a cooling system. I had pretty much everything else in hand.

That said, I've never been particularly satisfied by the S50US. It doesn't rev the way I want. It doesn't quite make enough power. It doesn't have enough throttle bodies. It looks quite utilitarian in the engine bay. You know, because it is. It's just a mildly built M50. It was never a long term answer. It just got the car on the road.

I dithered for a while on rebuilding the S14 vs. putting in the S54. Ultimately, though, the cost of rebuilding the S14 and the insane cost of replacement motors if I blew it up (think comparable to the 993TT) pushed me towards the S54.

At this point, figure $15-20k to do a home assembled rebuild of the S14 to a spec that would put down about the same power as the S50US. WAY more interesting motor. A little shy on power. VERY peaky. If only I'd bought half a dozen S14s when you could buy them in good running condition all day long for $3-5k.

S54s are about $4k in good shape. They made tons of them, so it'll be a while before they get scarce. They're actually quite reliable. They'll spin 8,600 to 9,000 RPMs. And 300whp is a baseline expectation. And I already had one in the basement.

Photo courtesy of clyde.

The easy part.

Motor out.
Motor loaded up.
Motor descending into the shop.
S50 and S54 together for a brief moment.

I had a relatively limited window on Mike's lift to get a few key items done in between my truck getting finished (a new fuel hard line turned into a frame off partial restoration :lol: ) and the next project - an engine swap for his neighbor's '70s Camaro. Yes, it's bitchin'. Or at least will be.

The key objectives for the time on Mike's lift were:
1) Install engine. This is a LOT easier when you can raise and lower the car instead of the lifting the engine in. I could do this at Doom, but why?
2) Build exhaust. This was the part that I really couldn't do at Doom. I don't have the equipment.

The original intent was to get this done in two weekends, but I got hung up by my original muffler plans not working out. The S54 wants either dual 2.5s or a single 3.5" exhaust. 3.5" exhausts are LOUD, and it's hard to make the clear the ground, and it's hard to get a good catalytic converter option for them without spending $$$$. So dual 2.5 it is. (Single 3" works, but you lose top end on the S54, and the muffler options aren't ideal.)

Still, three weeks later (and just ahead of a "snow storm"), I towed it home. Big thanks to Mike both for the use of his garage, AND for helping me push the M3 inside Doom after towing it home!

This is awesome! How's the truck doing after all these years?

The truck is doing great after we (mostly Mike because it was his COVID project) ripped it apart. :lol:

Had to pull the transmission again, because unfortunately, finding a flywheel and clutch combo that work with the transmission I picked turned out to be more complicated than I expected. The transmission was installed knowing that I'd have to pull it again because it's necessary for exhaust fabrication.

Pro-tip: When you're reinstalling the transmission, don't use a creeper. You lose all your leverage when you're on wheels.:lol::eeps:

Also got the exhaust painted black. I don't like shiny exhausts.

This brings us roughly to the present.

We're at the "it's a fucking mess" stage.

The worst part was that I had all the wiring neatly arranged and tucked away. But then I discovered that the intake manifold occupies the exact part of the engine bay that E30s normally use to pull the engine wire harness up from the block. Which meant that all the work I'd done to neatly arrange things had to be undone. Sigh. :mad2:

At least I have the wire length available. The wiring in the engine bay will be tidy enough once I've installed the wire harness carrier and cover. I'll need to make a couple of brackets for fuses and relays in the glove compartment. The S54 brings four wire harnesses to the DME, so there's a lot more to put away. It won't look anything like it currently does when I'm done. :lol:

Wow, thanks for sharing!

:lol:

Cool...
IMO - Messes are good. They result from work. :)