M20 or M30 swap.

[Jean]

Hi,

Since we have same cars and I did the b35 swap I can probably answer most of your questions.

Finding a manual m30 specific 260/5(used in e28s and others) or 260/6(used in e34 535i) is not going to be very difficult, these aren't exactly rare :)

Since the engine you are looking at is from an e28 it's most likely a b34 (double check it) and needs a different oil pan/pump assembly.

The issue here is you'll be doing just as much work labor wise to do either swap, since almost NONE of your current m10 stuff will swap over. m20 or m30 you'll need different tranny/driveshaft/exhaust/cooling system/wiring. The only major difference is that you'll need custom engine mounts to make the b35 swap and a few guys on here sell them.

Either swap will add weight over your m10, not just the engine alone but the tranny and exhaust as well.

If you can afford to get custom engine mounts or can make them yourself I would not bother with a b25 swap.

[Roysneon]

Hi guys!

I've recently acquired my first e30 project, an 84 318i. It's been sitting for a while, and from what I've gathered about the car, the M10 is tired and may need a rebuild or head gasket job. For the cost and time it would take to rebuild the m10 I'd rather just swap to something newer and with a little more power.

My dilemma is that I've found an E28 with an M30 and the guy wants $100 for the engine, wiring, ecu and anything else I want to pull from the car or $200 for the whole car. The only problem is it's an auto and I'd then have to source a manual transmission for it. This car will be more of a sporty daily driver that might see a track day or autocross somewhere along the line.

My main question is how much harder is the M30 swap, since the M20 came factory in an e30 and is the extra cost/work for the M30 worth it? I don't want to add too much weight to the car either, so that's a consideration as well.

I know I'll need to "massage" the firewall, get a different rad, and upgrade from the small case differential for the M30 swap, nothing that would stop me from doing it if the power over the standard M20 swap would be worth it.