Do you have a M20 hot rod or swapped Motor?

[nando]

yet they still rev happily! and so do M20s with big cranks. :)

fun fact: an S52 bottom end with lightweight aftermarket pistons is several POUNDS lighter than the stock M20B25 rotating assembly. Guess which one will rev better? ;)

[VinniE30]

yet they still rev happily! and so do M20s with big cranks. :)

fun fact: an S52 bottom end with lightweight aftermarket pistons is several POUNDS lighter than the stock M20B25 rotating assembly. Guess which one will rev better? ;)

Yeah because that's a completely different, newer engine. I could have told you that. Here's a better example - why don't you compare an eta to a M20B25? B25 will rev better. But lets not talk about examples at all since it's just anecdotal evidence. How about you give some actual reasons like I did before?

[nando]

the B25 has a much more agressive cam, intake, exhaust, tuning, etc. etc. of course it revs better. that's rediculous.

my motor with an eta crank also revs better than an M20B25.

having a lighter rotating assembly, despite the crank throw being longer, is a pretty dang good reason.

you seem to just want to argue that a motor with a longer stroke can't rev as high or as "fast" as a shorter stroke engine. to some degree that may be true but it's really irrelevant on the motors we're talking about. you can't go any further than 89.6mm on an M20 or M50 and the biggest crank also happens to be the lightest.

[N2MYE30]

I swapped my M20 for a M50 in my coupe with no regrets. The M20 ran just fine and didnt even leak anything. I just wanted to swap an engine to say I did it. A bud did let me use his garage and swap experience so that was very helpful. But It was more a personal goal. The look of a 24V in a e30 looks so clean (when done correctly)...even with all the plastics. Yes, gains were minimal but noticeable especially with a chip. I always wanted to maintaine the driveability of it as my plan was to keep it as my daily. I think it was on stands for ~3 weeks as I had it all planned out. (Build in my sig if your interesterd)If i had more coin to spend on a swap, sure an S5x would be in my engine bay but again, $$. My coupe is well balanced to me and im just fine with it. As long as it still puts smiles on my face, alls good.



I have been in a blue-printed M20 2.8 and WOW, just WOW! It sang just great and it moved to to match.

If I ever do another swap, id most likely will be a well sorted M20, nothing stroked, just a good old N/A engine.

...unless an S54 becomes more reasonable in price.

[tinkwithanr]

I haven't assembled it yet but I finally have all the parts to assemble my 3.15L M20. It's been designed to be the best of both N/A and Turbo (on ethanol when the time comes). At this point not much on it is stock:

- CP Forged Pistons 10.5:1 CR
- 288 Schrick
- +1mm Valves
- VAC Valve Springs
- Billet Rockers
- S52 Crank
- H-Beam Rods
- S54 ITB w/ custom cast manifold
- Welded Head
- ARP Hardware
- MLS Gasket
etc etc etc

At this point I have just as much money in it as I would for an S52, hell I probably could have got an S54. But all things taken into consideration instead of having a high-strung engine with 100k or more on it, I'll have a brand new engine that can rev just as high and make very decent power (~240-260 crank). Once boosted it should easily be a RELIABLE 400-500 HP. Sure a stock M20 can boost to 500hp on a stock block, but for how long?

Other considerations for my decision to build up the M20 were weight and size (since it's going into a 2002) and 'period correctness'. As other's have mentioned, the sound from a build SOHC I6 is great. An S54, while being great in it's own right, just wouldn't be right in an old vintage car.

[broach328]

m52b28 with s52 cams and 3 years as a daily driver and couldnt be happier with the fuel economy and weight balance/handling.

[iamsam]

y'all just convinced me to swap an M30B35 into my E30...

[camip]

If money wasn't a factor I'd go s14 maybe turbo just for the hell of it. Motor is period correct sounds badass and it is light. We drive light FR cars I don't see a need for anything over 300hp.

As of right now I'm doing I'm gathering parts for a m20 head swap. Why you ask because I feel pride opening the hood and knowing thats the block my car came with in 1985. Also it's super cheap and and big jump over the eta.

[Wanganstyle]

your contradicting yourself and making claims with no supporting evidence man first you said we need euro motors or s54s because s52 was not enough power for 2012. its safe to assume most peoples e30 weighs around 2800 lbs. with an s52 that puts you at 11.66 power to weight ratio. The new scion fr-s is also 2800 lbs but with 200 horsepower giving it a 14.0 power to weight. I mean if your setting your goals high and want to be comparable to 911s or e92 m3s then I agree youll need s54 or better but I would imagine most people arent looking to spend 6k on a swap with more power than an e30 can actually use. and i dont know what to think of the american v8 comment. my point is, for an e30 you dont need 350 hp to keep up or even beat the current "sports cars" of 2012.

Nissan quest minivan is about 300hp these days
so is a Honda minivan.

V6 camaros and mustangs are over 300 hp.

M20's built up make ~ 200-220rwhp.
S52 will make 220-240rwhp

24v engine is ~50 lbs and an ugly fit compared to a 12v sohc M20 - the rubber band M20 is pretty compact and light weight; the head and overall dimmensions fit the e30 body perfecty - as is the Original BMW intended design.
no room for mechanical fan = engine weight is moved forwards in comparison to the original SOHC M20 compact belt drive engine



if one wants POWER than a LS7 will bolt right into the e30 chassis with the proper fit kit. its no heavier than an iron block 6.

fit of GM v8 into e30 seems better for track use than a BMW dohc 24v I6 into e30. the GM v8 has the advantage of ridiculous cheap power and alloy block (and tiny heads)

[James Crivellone]

I love my 2.8L M20 Stroker that I have in my Mtech1, however whenever I build my next car (E30 Touring) it will have an M54/S54

Stroker M20's are awesome motors if you are looking for a certain type of powerplant. For my early car I wanted a factory built motor that was era specific to the car. I didn't feel an early Mtech1 car deserved a motor that had a modern look to it.

I have over $5000 into my M20 and make 166hp/168ft tq at the wheels. My roommate has an M52 + S52 cams and makes 200hp at the wheels for less than half what I paid.

If you want HP and modern convinces go for an M5X S5X Motor. If you like the sound of valves chattering and old school charm build a stroker M20. I know its expensive, but its not just power that you are looking for.

Folks who drive my car say whoa this is fast for an M20... and for my mtech it was exactly what I was looking for. Hell I'd love to find a dbilias setup for it.. not for HP, but to really finish off that old school built motor look.

[nando]

james, you could still make a considerable amount more power.. if you finally ditched motronic. :p

but, I also understand not wanting to screw with a perfectly good running motor. I just think that I shouldn't be making similar/more power than you with basically the same motor, plus the extra penalty of AWD.

[42000]

I agree with nando, sure a junk s50 is cheap, but then what happens if it needs something or you wanna rebuild it? WAYY more money than a SOHC m20. I would rather have a fresh built motor than a old motor that came out of a junker...

Plus, m50s look like absolute shit in an m20 engine bay! Maybe a euro s50 or n s38 but I hate all that plastic bull shit... I also like the s14 turbo idea:p

The only thing that worries me about m30 swaps, s5x swaps, etc is the weight... Has anyone tracked their car with an m20 then swapped the car and tracked it again. (without other major mods.) Is there any noticeable difference in handling. Can you feel the weight distribution offset?

Turbo guys: Who has tracked their car? Pretty much all these highpower turbo e30s cant hold traction at all. I want a turbo set up but want linear power. I want to blast through the corners, not slide around them.

[James Crivellone]

james, you could still make a considerable amount more power.. if you finally ditched motronic. :p

but, I also understand not wanting to screw with a perfectly good running motor. I just think that I shouldn't be making similar/more power than you with basically the same motor, plus the extra penalty of AWD.

One day I may go MS3, but it would need to look perfect in the bay.

The engine runs great, I know it can make more power. Its just a cost I don't want to mess with at the moment.

[e30trooper]

James, what kind of whp did our spec put down? Stock rebuild?

[Kovs]

Motor swap Euro S50 bored out to a 3.2 This engine lives at 7K all day long which is why I choose it - it's a track car and I wanted something that was reliable and durable enough to withstand track day beatings. Oh yeah, I drive my car to / from the track.