Are M30 swaps still worth it?

[JonnyOg]

Hey just curious if its still worth it to go m30 over 24v. Are parts getting more scarce? I would love an m30 but I feel like its going to get more and more difficult and expensive to keep them on the road vs 24v.

[Bearmw]

If you properly rebuild an M30 it is good for 200 plus thousand miles and there isn't a whole lot to go wrong. Comparing 12 valve to 24 valve is apples to oranges. It's true that there are fewer old engines and transmissions available but that is true of any older car. If you buy a 20+ year old engine it is likely to be fairly used up but the m30 bottom end is notoriously strong.

[glnr13]

mpgs... the m30 is thirsty.

[CorvallisBMW]

^ very true.

The m30 will have more low- and mid-range torque, but doesn't pull very hard up top. 24v pulls harder for sure, and also gets better mileage. Parts availability I don't think is an issue, as the m30 is dead reliable and there are still thousands of them out there.

[tspangle88]

What about weight? I know both add some, is the M30 heavier?

[CorvallisBMW]

Yes, by about 60 or 70lbs IIRC. However you can keep your A/C intact if swapping from an m20 to m30, with 24V you need custom lines and an r134a conversion.

[ThatOneEuroE30]

It's also cheaper. You can complete an m30 swap for the price of an s52.

[george graves]

If you properly rebuild an M30 it is good for 200 plus thousand miles and there isn't a whole lot to go wrong.

If you just change the oil and do a coolant flush every few years, you'll get 250k-300k out of an m30 without ever opening it up (other then plugs and maybe a timing chain guide)

M30s have so much down low grunt it's great for a DD. A m30 will happily start really moving an e30 as low as 1500 RPMs. Starting out in 2nd gear is fun too. It's a great "period correct" motor. Nothing wrong with a s50 - it's just a different motor.

For me, if it's a street car, I want Tq, not Hp. With that said, I think my next motor is going to be a m60 4L. It's about the same amount of work.

I don't get people that do a m50 swap, unless it's to replace a failing m20 motor. Doesn't seem worth the grief - not to mention, head rebuild time it's going to cost more.

My 2 cents.

[The München Monster]

I like older motors - less electronics - less to go wrong. I'd call myself a nostalgic person but I'm only 20... anyways i love my M30. Guy who sold it to me sold me a fucked one, head gasket blew if it wasnt already blown (Thermalweld fixes that), pretty much replaced everything at this point. But its way better than my M10 thats for sure

[Mr. Burns]

I think my next motor is going to be a m60 4L. It's about the same amount of work.

[McGyver]

What about weight? I know both add some, is the M30 heavier?

Yeah, it's a max of 70 lbs heavier. And since the m30 is longer, you'll about that extra weight distributed in the same place as an m20/m5x plus about 3" further forward. Weight distribution and the extra weight aren't going to be noticeable in a street car. Even on an autocross car, you're going to be hard pressed to feel it. Weight really isn't an issue.

It's also cheaper. You can complete an m30 swap for the price of an s52.

It looks like I have around $1300 into my swap including the engine, trans, lightened flywheel, condor mounts, electric fan, and all the other bits and pieces. I still have to sell my old engine/trans and all the parts off of the e34 I bought for the engine. So really, I could get this swap for free. Buying a whole running parts car is the best way to go.

Bottom line OP, a m5x is never going to be as fast/torquey as an m30b35. Continuing, most s5x engines are getting to be pretty high milage, so vanos is leaking and dying and those engines need a rebuild to get power back. An m30 will cost more in gas than a newer engine, but should be about the same as an m20, and it will be cheaper to maintain than a newer engine. Plus an m30 feels like a manly engine, m/s5x feels so smooth and asleep.

tl;dr, m30b35 is the only way to go.

[lukeADE335i]

They are a performance bargain for sure - even still.

[FubarE28]

Look at it this way when they were brand new, they put the M30 in the 535i, and the M50 in the 525i.

[Jb325is]

My built m30/m90 felt faster on the street than my my s54 in the same car. I don't have any experience with a stock m30, but mine only made 225whp, so nothing crazy

[wannaBMthree]

My built m30/m90 felt faster on the street than my my s54 in the same car. I don't have any experience with a stock m30, but mine only made 225whp, so nothing crazy

What would you recommend for a mild street build? Already got headers, exhaust, ltw flywheel.

Noticed you had experience with ITB's but not sure its worth the trouble (more of a dream than anything).