m30b35 vs. m50b25

[619E30]

Alright, so i have a stock 1990 325i and I want to swap in a bigger motor. I have a 1989 735iL and a 1992 325i non-vanos. I wanted your guys' opinion on what would be a better for a daily driver and maybe a little bit of autox. I know the m30 would be faster but I heard that they have cooling issues. So my question is, what would be the better swap reliability wise?

[ahriley91]

Newer motor, newer internals. It's gonna be more reliable. And from what I've heard, I think that the m50 is a little easier of a swap. I just put in a m50tu into my e30 and it was pretty straight forward. Just do a lot of research. So if I was you, do the m50.

[619E30]

Alright. What's the difference power wise from a m20 to a m50?

[xwill112x]

like 20 extra horses

[Wh33lhop]

You'll feel the difference between the M50 and M20, especially if your M20 was tired and you chip the M50.

I went from a Mark D + 19lbers M20 to a Mark D'd M50NV and it was pretty noticeable.

[Jb325is]

m30's are just as reliable as m50's.. They're also cheaper, have more power, more torque and weigh less.. I do think the m50 looks better, but I don't know if the swap is actually easier than the m30.

[rThor432]

and weigh less..

Are you sure about that? Either way, they are a good bit longer and put the front of the engine a lot farther in front of the subframe. M50 swap is stupid easy. Not sure about the M30, but I know that more "fabrication" is required.

[5KWattson]

The m50 stock may not have as much power as a m30 but the room for improvment is far greater as a DD now if you want to turbo your swap at some point and build rediculous power I would do the m30, but I have to say I love opening my hood at car events or little meets and having a croud gather trying to figure out why my motor looks so new

[mightywhitey]

since were talking about engines, does any one know the weight difference from a m52b28 iron block vs aluminum?

[5KWattson]

I think it's 30-45 lbs I can't remember exactly now

[619E30]

So the m50 would take less fabrication?

[weaksauce]

So the m50 would take less fabrication?

motor mount wise I think is the only difference.

[Jb325is]

Are you sure about that? Either way, they are a good bit longer and put the front of the engine a lot farther in front of the subframe. M50 swap is stupid easy. Not sure about the M30, but I know that more "fabrication" is required.

I've seen it both ways, but one way or the other they are very close.

As far as more fabrication, the m30 can use the stock harness. If you don't use the stock harness you can use a 20 pin e34 harness, which will plug straight into your e30. Motor mounts would have to be fabricated but they are readily available. m30 swap will also use your stock trans crossmember, stock exhaust if you want, etc.

[619E30]

Do you think a m30 would be cheaper to rebuild because they both need head gaskets

[e30polak]

m30b35 > m50 NV

m50 vanos or Obd1 M52, both with m3 cams and tune > m30b35