I want more power. Engine swap? m20 2.8? What do you suggest?

[clydesdale]

Thanks for the "big boy" comment. I have searched the 24v swap area. I was looking for a thread that explained why to choose which engine and what the differences were. I was unable to find such a thread. I then searched yahoo for "differences between m50 and s50 engines" and I came up with a thread from bimmerforums that did not have one reply. In the process, I have learned about the brake booster mods needed, drive shaft and tranny concerns, oil pan, etc....So, trust me, I have started doing my homework. I just don't feel like spending 2 nights at the computer for a question that can be answered in a few sentences.

[sticksdaman]

http://www.e3024v.com/board/index.php?PHPSESSID=60ebf3faa3c133fc2ab6825c27037712&board=4.0

This might prove useful.... I'm looking to do this one day in the future.

[ben312]

The "m" is from the none m car and the "s" is from the m model car. Kinda backwards but that's what it is. The m50 swap is by far the easiest of the 24v and there is plently of info on here and other sites on how to do it. You will end up spending a lot less money and a lot less time doing a 24v swap over building an m20. U can make the power with the m20.... Question is how much time and money do u wana dump into it before you get even close to the 24v.

[Emre]

They will cost close to the same, and the 24v is all around a better decision.

Keep in mind that when you say "they cost the same," you're comparing the cost of swapping in a used 24v engine to the price of building a brand new 12v engine from the ground up.

Considering donor M50s are already 10-19 years old and most will have very high miles on them, this is not a trivial difference.

For the most part, the choice is between installing an unknown 15-year-old, 150K mile M50 that someone got from a junkard vs. installing a fresh, properly built M20 stroker that you know was done right.

I know which option I would choose.

[Jean]

^ exactly. $500 m50 swaps FTL.

[ben312]

so buy an m50 and build it. its more power, better power band. you'll spend jsut about the same amount and in the end more worth it

[Brian D]

so buy an m50 and build it. its more power, better power band. you'll spend jsut about the same amount and in the end more worth it

I'd be interested in the price comparison between a single cam vs. twin cam rebuild. Straight rebuild, mildly hot rodded, full competition...I think the newer engines are significantly more expensive, but I haven't really dug into it. Aren't aftermarket cams like 1200 bucks a set for a x5x?

[noE30]

I'm also interested in this subject, as I have been thinking about doing a mild build with my m20 to get a little more power (probably just a 2.7 stroker, cam, chip etc). But then again I kinda want to swap in a 24v.

In the long run which is cheaper a mildly built m20 or a fresh 24v swap? And by fresh I mean rebuild as needed considering it would be a used engine.

[ben312]

I'm not sure about total price. The new motors have more parts availible and more after market support. Also I think in the long run you get more power per dollar in the 24v then the m20.

[thereisnoyun]

so buy an m50 and build it. its more power, better power band. you'll spend jsut about the same amount and in the end more worth it

there is no freaken way that is true. not in a million years.

1.) you have to get all the proper swap parts and the motor. which m20s can be had for dirt cheap.
2.) twin cam refresh would have more component that would run much more than the m20.
3.) rebuilding the head itself should = to twice the amount of work a m20 head required. which should effectively cost 1.5 at least as much.

Do the correct build up for both m20 vs. m50 you can be sure to eclipse your budget over the m20 by 2x if not more.

[ben312]

People spend well over 4k getting to the hp level of a stock m/s5x swap out of a m20. Just rebuilding and finding parts for an m20 is much cheaper. But he wants overall power. To get the power of an m/s5x swap you will throw a lot and A LOT of money into that m20. That's just to get close to the power of stock 24v. Poster above said he had over 4k into an m20 and was getting 200hp. Power per dollar is much better on the 24v. You have to bore, stroke, cam, p&p, high compression pistons, chip, and do some decent head work if not more just to break that 200hp mark. To much money for no power. You may end up spending more on the 24v but it will end up with much more power and wider power band.

[nando]

I don't think that many people spend over 4k on the engine alone, even with a schrick and $1200 pistons I don't think mine cost that much.. maybe if you include engine management and tuning. But I'd want that for any engine, even if I had an M52.

This is such a tired argument. If somebody wants to build an M20, that's fine. If they want to swap, that's fine too. It's almost apples and oranges anyway since you're basically comparing a used swap motor to a brand new M20.

if you really want to argue $/HP, it's not in the M50 engines. It's in forced induction. even 200whp from an M50 is pretty weak all things considered.

[ben312]

Its not so much the money as the work that kills me about the m20. Its a great motor. But if I was about to start a full build I would go bore, stroke, high comp pistons, over sized valves, race springs, race bearings, cam, chip, shave the head, P&P, short runner intake, race headers(if staying n/a) and new exhaust. With that much time, work and cash into a motor I would like to see over 200whp which that would do but not by a whole bunch. Now get and m/s swap and throw a cam, new springs, new headers and maybe a P&P and its around the same hp with a lot less effort and time if anything.

[nando]

yeah, and that's great. But why troll the M20 section to tell people what they already know?

[lennon]

Its not so much the money as the work that kills me about the m20. Its a great motor. But if I was about to start a full build I would go bore, stroke, high comp pistons, over sized valves, race springs, race bearings, cam, chip, shave the head, P&P, short runner intake, race headers(if staying n/a) and new exhaust. With that much time, work and cash into a motor I would like to see over 200whp which that would do but not by a whole bunch. Now get and m/s swap and throw a cam, new springs, new headers and maybe a P&P and its around the same hp with a lot less effort and time if anything.

yeah and i would like to see 500whp, but i dont expect it from an m20 or s52. you start with a motor that makes 168 horsepower at the flywheel brand new, what the hell do you want from it? i dont think you "get it". people spend lots of money and time rebuilding all types of engines, including ones that only make 100hp or less. its not all about what "can" make the most horsepower.

to each their own, as long as its not stupid.