M20 2.8 stroker vs M50b28?

[SA E30]

Guys I figured I would ask opinions on this, as I'm torn.

I love the m20 and I know them inside out, yet the more modern M50 is a tempting choice.

What I have in mind is that if I go M20, I will build a mild stroker (nothing like my old 2.9lt 160wkw m20 stroker). I was thinking M50b28 crank and rods, m20b25 pistons decked and pocketed, a gas flow, camshaft, header and chip.

How would that compare power wise to a stock M50b28?

Bear in mind that this is going into a M10b18 carb equipped 316.

This is the car:



Short build thread here:

http://www.r3vlimited.com/board/showthread.php?t=190312

[structured]

I vote M20, but I am also building one myself so I am not impartial. There is no doubt that doing the M20 right will cost more than swapping the M50, though.

[gregslow318i]

I vote M20, but I am also building one myself so I am not impartial. There is no doubt that doing the M20 right will cost more than swapping the M50, though.

disagree 24v or nothing, everything about the m20 sucks...from the oil pans that leak to the rockers that break and from the timing belts that snap to the oil return tube and there vacuum leaks....I could go no

worst motor bmw ever built....and the only one with a tbelt

[Tbolt]

disagree 24v or nothing, everything about the m20 sucks...from the oil pans that leak to the rockers that break and from the timing belts that snap to the oil return tube and there vacuum leaks....I could go no

worst motor bmw ever built....and the only one with a tbelt

hey now, cant be hating on the m20!

ill be swapping to 24v this summer but ill always enjoy an m20

[blunttech]

I like the m20 also for what it is. a hardcore stroker m20 is pretty raw. but 24v is where its at

[gregslow318i]

hey now, cant be hating on the m20!

ill be swapping to 24v this summer but ill always enjoy an m20

thank you

Ill say it again m20 can suck my balls

[structured]

disagree 24v or nothing, everything about the m20 sucks...from the oil pans that leak to the rockers that break and from the timing belts that snap to the oil return tube and there vacuum leaks....I could go no

worst motor bmw ever built....and the only one with a tbelt

All of those things can be overcome with regular maintenance. If you can't handle that, then you probably shouldn't own a 20-year-old car.

Timing belts only snap because people are too dumb/lazy to replace them.

Rockers should be replaced if building a stroker anyway. Metric Mechanic uses OEM replacements now on all of their crate m20's and have few - if any - failures.

[gregslow318i]

All of those things can be overcome with regular maintenance. If you can't handle that, then you probably shouldn't own a 20-year-old car.

Timing belts only snap because people are too dumb/lazy to replace them.

Rockers should be replaced if building a stroker anyway. Metric Mechanic uses OEM replacements now on all of their crate m20's and have few - if any - failures.

ever herd of a timing belt break on a m50...or a rocker snap on a s52?

[Cabriolet]

IMO the M50 is about the same as the M20. if you want performance go S50 or S52. just drove a m50 with cams and it kinda sucked. my good friend turned his eta in a 2.8i and its stupid fast. if u are gonna swap go S50b30 or greater...

[structured]

ever herd of a timing belt break on a m50...or a rocker snap on a s52?

No, but I have heard of the hydraulic lifters going bad not to mention the vanos systems. Both are certainly more expensive and probably more difficult to repair than rockers on an m20. I have heard of them pissing oil out of the timing cover and oil pan as well.

I'm not saying that m20's are the best engines that BMW ever built, but they are not scrap metal either. IMO, people who think that m50's are some magical flux capacitor for e30's would probably fit in better over on Bimmerforums. :giggle:

[reelizmpro]

ever herd of a timing belt break on a m50...or a rocker snap on a s52?

Never, only because they didn't have timing belts or rockers. I agree the M50 family of engines is superior, as they should be since they are a more modern design with self adjusting valves. If the OP asked this question 10 years ago I would say stick with the M20 but today with M50 prices bottoming out and swaps being so common, it's almost foolish not to and this is coming from a "purist" so to speak. I would go with a supercharged M52 from a HP per dollar perspective.

Since the car you're starting with is a 316, go with the M50b28.

[mikeedler]

ever herd of a timing belt break on a m50...or a rocker snap on a s52?

oh boy oh boy!!!!!
you ever heard of replacing the 800+ dollar vanos unit on a M20, and you wanna talk about vaccum leaks,,,,,,
maint items/repair parts cost nothing in comp. to the M50 stuff-over here anyway.

not that I have a great love for the M20 but it is not all that bad, like said here before, with a bit of maint. an M20 will run forever too.
oh, and btw, the M40 also ran a timing belt,
and if you really wanna know the worst motor ever produced by BMW-- look no further than the N47 2.0 diesel.

[Drew325is]

Look for an alloy block M52B28...expect 30% more power at the wheels than a stock M20B25, and 30kg less weight over the front axle. It's like having 6 cylinder power, and 4 cyl handling all in one!

[briansjacobs]

I did almost no cost spared M20 2.8 and love it, if you are going 2.8 you should not have rocker problems as you are not going to be turning high enough RPM to worry about it, I did the VAC billet rockers but I never really run past 6300 RPM as going beyond that is slower that was a waste of money. Timing belts? routine maitenance! my car is a full blown race car and I never had a belt go, do your maitenance and dont worry, vacuum leaks, it is a 24 year old car replace the lines, done.

[Nic01101011]

Look for an alloy block M52B28...expect 30% more power at the wheels than a stock M20B25, and 30kg less weight over the front axle. It's like having 6 cylinder power, and 4 cyl handling all in one!

Aren't US M5xs iron?
If they were Al it would be a very worthwhile conversion I think..