M20 vs M50

[AlexSutherland]

Why are M50 swaps pretty common? It makes 189 hp and the M20 makes 170 hp. The difference isn't too great. I'm curious just.

Is the M50 a cheaper engine? Is it easier to make more power on the M50? Is it a more reliable engine than the M20?

[agent]

They're not common anymore. M50 swaps were popular back in the day because they are OBD1, and OBD2 wizardry hadn't been cracked yet.

These days there's practically no reason to swap in an M50, unless maybe you're coming from an M42 and don't care about keeping the car original.

If you're going to swap, OBD2 is the way to go - period.

[AlexSutherland]

Thanks Agent! I was always curious to why they were swapped.

[wworm]

in the m50's defense it has a timing chain, can be found used with less miles than an m20 (not as true as it once was) and were used in loads of cars so availability was super high, however, it's hard to justify an m50 swap over an m20 refresh. OBD2 is just nicer to have and the cost difference is negligible. Bang for buck an m52b28 is a much better swap than an m50.

[ZekeTheSneak]

^m52b28 at a minimum. With todays tech I would keep the m20 and convert it to megasquirt. Then boost. They make it so easy now why not? Plus the m20 fits perfectly.

The days of low mile m52s are over. Might as well go m54 at this point...

[nando]

"timing chain" is a weak ass argument. Chains still wear out, and a 25 year old M52 is going to need some work.

If you want a very slightly more powerful engine, great. If you just like the 24v engines, vanos, etc - awesome! But the argument over chains vs belts is retarded. In 20 years you would only have to replace a belt 4 times, it's cheap as dirt and easy to do. Also, belts are actually more efficient.

But replace all the timing chain bits, sprockets, guides, tensioners? That's going to set you back a few bucks an it's not going to be fun unless the engine happens to be on a stand..

[e30davie]

You dont have to adjust the valves on an m50 (well very often, like once every head gasket). And the engine doesn't go tick, tick, tick, tick. So that is one advantage.

[nando]

They'll go tick tick tick when the hydraulic lifters collapse, and then there's nothing you can do but listen to it or rebuild the head. :p

[pazi88]

They'll go tick tick tick when the hydraulic lifters collapse, and then there's nothing you can do but listen to it or rebuild the head. :p

Or just change the lifters which is few hours of work :D

Here people do m5x swaps, because m20b25's are rare and m5x engines are cheap, plentiful, easy to swap and reliable.

[PNWE30M50]

Granted I came from a m20b27 e30, but have driven plenty of m20b25(s), and I will have to say my m50b25tu swap seems night and day from the m20(s). My m50 is lightly modded though.

Also, from my understanding, to get a m20b25 over the 200bhp(n/a) will cost you a lot of time and money. Or just money.

Whereas the m50tu will simply need a tune to achieve that. Then you can go even farther for a n/a application with s50 cams, 3.5" Euro/540i MAF, and a proper tune. AKA 200+ WHP.


If I had more disposable income I would have gone with an s50/2 swap, but you live and you learn.



Just my 2 cents.

[agent]

An M50TU is essentially an M52, just as an M52TU is essentially an M54. Also, it's OBD2.

I think what most people are referring to when they say "M50" is the OBD1 non-vanos version.

[nrubenstein]

An M50TU is essentially an M52, just as an M52TU is essentially an M54. Also, it's OBD2.

I think what most people are referring to when they say "M50" is the OBD1 non-vanos version.

I can’t agree. I think almost everyone who says M50 means M50TU, which is why people explicitly call out that they’re talking about a non-VANOS M50.

[digger]

An M50TU is essentially an M52, just as an M52TU is essentially an M54. Also, it's OBD2.

I think what most people are referring to when they say "M50" is the OBD1 non-vanos version.

The m50 is the torqueless m52b28

[nando]

An M50TU is essentially an M52, just as an M52TU is essentially an M54. Also, it's OBD2.

I think what most people are referring to when they say "M50" is the OBD1 non-vanos version.

The M50TU is OBD1 for certain. OBD2 didn't exist until 1996.

[agent]

Yep, my wording could have been better there.