Bulletproof BMW Engine

[digger]

BMW engines with rocker arms weak point is rocker arms.

possibly the M20 is more prone due to the bigger rocker ratio? i don't follow M10 and M30 forums to know if the issue is as prominent accounting for the lower number in existence

[5ickride]

I have a 68k mile, all original miles, M20 eta at the moment. I love it, it's got nice pep to it and pulls pretty good. There is absolutely nothing wrong with the engine. So if I want more power, I was thinking swap, stroke or turbo. M30 is at the top of my list for no other reason then I heard it was a solid engine with great torque. But I still hesitate to let go of a low mileage M20 that I can squeeze more power out of. So possibly stroke or turbo at this point.

[E30_Pare]

with a e30 with such low miles it would be a shame to molest it. Think about how rare a 68k e30 is compared to a swapped one. If anything it would diminish the value especially by putting in a motor with unknown mileage/history.

[BlackbirdM3]

I'm going to vote for the S14. As long as you pay attention to it, its a very well built motor. Sure, you have to adjust the valves, but you have to do that on M20s, M30s ect. Its a very well thought out motor that is easy to work on (should you need to). Sure rod bearings are prone to being beaten to heck, but only if you lug the motor or fail to run good fuel (or run an over-achieving, over reaching chip that puts the timing and fuel right on the ragged edge.)

Its got a double row timing chain, fully counterbalanced crank, valves that are directly actuated rather than using a rocker arm (but yes the shims can get launched in some high rev instances.

Nope, not cheap to build, but then well built motors aren't cheap to begin with.

Will

[Mr_Tripp]

This reminds me of this picture



DT.

[mkcman17]

I'm surprised at the m54 love...I've got a 3L sitting in my shed. Hmm.

[digger]

I'm surprised at the m54 love...I've got a 3L sitting in my shed. Hmm.

M54 far from bulletproof though, any sort of revs and oil pumps crap themselves and things start shaking loose

[einhander]

Has to be the M30. Every engine has a weak point, but these don't require any voodoo magic to get right.

M10 would be a close second.

[LJ851]

Has to be the M30. Every engine has a weak point, but these don't require any voodoo magic to get right.

M10 would be a close second.

Yes.

[slammin.e28]

M30 hands motherfucking down.

Fuck M20 because timing belt = bullet, and breaking = death.

But lets face it, BMW knows how to build a goddamn I6.

M10 us the under sung hero too. They do last, but they are basically an M30 minus 2 cylinders, or vice versa, so I put them together.

FWIW, I've never had an M30 break a rocker and I've taken them above and beyond the indicated redline on all of my cars. ;)

[5ickride]

with a e30 with such low miles it would be a shame to molest it. Think about how rare a 68k e30 is compared to a swapped one. If anything it would diminish the value especially by putting in a motor with unknown mileage/history.

Great point.

[BobombETA]

S52/M50 is maintenance free....no timing belt, no valve adjustments.

Weld the pump nut just once, replace the VANOS every 120k miles and you're good to go!

Yes but, cooling system.

[einhander]

Yes but, cooling system.

Easily fixed.

At least my M50 was.

[BobombETA]

Easily fixed.

At least my M50 was.

Oh I know :) but it's a weakpoint.