opinions? m50-m52 or stay m42

[z31maniac]

considering the m42 are so damn self destructive and ticking time bombs.

Really all you have to do is keep the timing gear in check (just like a 24v) and it's no more ready to explode than any other BMW engine.


OP, I've also had an M42 and an S52 car.

Leave the M42 in it. COP/lightweight flywheel/chip.

[Mr.SWISS]

Someone correct me if I'm wrong but wont the getreg 240 bolt right up to a 24valve and even let you use the stock trans cross member?

Correct, probably the easiest set up for a swap, no dicking with drivetrain,shifter,etc..

[rThor432]

Leave the M42 in it. COP/lightweight flywheel/chip.

I agree, this transforms the car. I put a JBR 8lb. flywheel in mine and it was a huge improvement. Didn't hurt the idle or make it noisy either.

Yeah, if you keep the chain tensioner in check there isn't a problem up to at least 200k miles. Usually the chain tensioner gets weak and the chain beats up the guides and it goes downhill fast from there.

[Leo_328i]

I've got an M40 flywheel lying around to chuck on when my clutch goes (its getting a big weak now).

If I end up doing the swap I'll be doing it with an M52 B25 (alloy block in Australia) or M50TU B25 to maintain a 'rev happy' character.

I've got an E36 328i and driven E36 325is back to back and the 2.5l feels so much more free-revving. I can see how an S52 would be overkill for daily driving but I reckon a 2.5l would be the go.

2.5l produces the same amount of torque the M42 does at 4600rpm at around 2000rpm which would also be very useful :)

[z31maniac]

I agree, this transforms the car. I put a JBR 8lb. flywheel in mine and it was a huge improvement. Didn't hurt the idle or make it noisy either.

Yeah, if you keep the chain tensioner in check there isn't a problem up to at least 200k miles. Usually the chain tensioner gets weak and the chain beats up the guides and it goes downhill fast from there.

And I'm starting to think that even a lot of those, it's really the oil pressure relief valve, not allowing enough psi at idle/low rpms, which doesn't give the tensioner enough PSI to work properly.

There is an updated part as well.

[chondamx]

I am in the same boat as you; torn between keeping the M42 or ditching it in favor of an easier to build (bigger numbers) platform. If the M42 could be kept above 4500rpm all the time it would be a fun little motor, but in a daily driver that is obviously not realistic. That is my single biggest gripe with it and its not even its fault. Its a 1.8l fourcylinder, I do not expect it to have any aww inspiring torque in its factory form.

My predicament? Do I keep the M42 and throw on a milled M20 flywheel, new clutch, chip, COP, and maybe that Garrett sitting on the shelf...or do I swap in an M50tu with S50 cams and software? The usable power of the M50tu would be much more daily driver friendly and would still be rev happy with the S50 cams. The boosted M42 would be lighter and a helluva lot of fun to drive (so would the M50, right?) and probably not as reliable. It comes down to two things for me, neither of which even relate to the engine choice. One, I have a 318iS, and a 318iS should have an M42; anything else just seems...wrong. Two, Everyone and their girlfriend, mom, and sister dive an m5X swapped E30...I think i might just try my hand at something slightly more original.

Of course, all of this comes from a guy who drives a worn out old 318iS sporting a sweet Volvo lip and some pretty purple Sportmaxs. So, take it with a grain of salt...maybe two. I will have to agree wholeheratedly with Thor, though. In the perfect world, there needs to be two E30s involved. I road trip in mine often, and I am not certain I would feel comfortable drive a turboed M42 across the country. The M50 car would be my daily/road tripper, the M42 the stripped toy. Good luck.

-Chris

[M-technik-3]

no it's not.



OP do the m52. IMO, best e30 swap to do of the m50 family motor hands down. m52 now, if you want to pep it up, s52 cams later. You'll have s50 power for $600 and a perfect candidate for boost later on. Obviously the entire swap will cost more than $600 after all said and done but definitely worth it, considering the m42 are so damn self destructive and ticking time bombs.

Do the headgasket prior to installing it thou. Seems all M52's I come across have or are fail HG's. Nice engines for the money without a doubt and then OBD I just makes it very nice.

[weaksauce]

yeah, i'm going to throw the s50 crank i have in the m52 and call it a day.

stay tuned for more fun.

[phreshkid]

yeah, i'm going to throw the s50 crank i have in the m52 and call it a day.

stay tuned for more fun.

Why would you do that? I have always heard of the opposite: throw an m52 crank into an s50 and call it a day.

Reasons behind your statement?

[justice101]

anyone know what kind of mileage the m52 would get?