Pondering on m30 swap. I have some questions.

[mbonanni]

Well I have been looking at the m30 swaps more closely lately. I got the write up from the forum member, but I still have some questions.

The 1988 e28 535i/s comes with the 3rd generation m30b35 correct? In the swap writeup it said that the e28 motors are not the best candidates for a swap, and e28's are plentiful around me and I would want to use an engine from one of them. What is the issue with them?

If I have an auto e30, and a full 1988 535is car with manual tranny, can I use the motor tranny from the e28 and drop it in my e30?

The whole different car/generation motor kind of threw me off gaurd.

thanks

[kronus]

no it doesn't. All e28s came with M30B34s.

An easy way to tell is to check the casting on the intake manifold. B35s have 3.5 on there, B34s have 3.2/3.4.

B34s are not ideal because they are less powerful than B35s and have an older version of Motronic (1.0 vs. 1.3).

Also, the e28 has a mid-sump pan and you'll need a front-sump pan from an e32 or e34.

[mbonanni]

Ahh makes sense! thank you!

[Grand525]

The simplest m30 swap for e30 would be from e34 535i or e32 735i

[mbonanni]

If I put this into an automatic 325i what tranny could I use?

I understand the e28 trans works, which is an option. Then I buy a driveshaft from an early e30? to have the correct output size?

[kronus]

You want a big-guibo driveshaft most of the time. These came on the 86/87 etas.

There was one year the e28 had a weird, different transmission called a getrag 265, which was a few inches longer and requires the driveshaft to be chopped to fit. Don't use that one, it's a headache.

[mbonanni]

Okay cool.
That clears things up.
If I have anymore questions I will post.

Also I noticed youre in the bay. So am I. I'd love to ride in an m30 swapped e30 sometime. If you ever go to meets maybe we could work something out? haha Or wait, do you you have a m30 swapped track car?

[kronus]

I'm driving out to Vacaville in an hour, amusingly, but the m30 car I have is a lemons racer, so I won't be driving it because it's not extremely road legal.

[kronus]

HOWEVER if you want to come to the peninsula and check it out, we'll be working on it most of the weekend, probably.

[mbonanni]

Haha interesting. I will be at work. making a lousy $6 per/hr. Its a long story. I am quitting soon.

Is $1000 a lot for a 535i e34 with 200,xxx miles as a donor car for a swap?
Or would It be mor elogical to just buy the motor and parts?

[kronus]

We got our motor for 200, but you have to get lucky and find a deal. The trans was 85 from a junkyard.

The whole 535 won't get you many other parts you can use on an e30, but it's more common to find one of those than just an M30, so if you find a deal, go for it. However, most of them will be automatics.

200k is not a lot for the motor, but if it hasn't been looked through I'd still refresh it while it's out. Replace chain guides, tensioner, eccentrics, stuff like that.

Jean (in Sacremento) was supposed to have an M30 coming out of his car soon, maybe see if he's still doing that.

[mbonanni]

Jean, is that his screen name? I will definately hit him up

thanks

[kronus]

indeed it is

[mbonanni]

thanks

[Bearmw]

Even the most basic m30 swap will cost some bucks. Maybe you can find most of everything in a "kit" that someone has given up on finishing but more likely you will have to source a bunch of parts. You will most likely have to source custom mounts, an e28 radiator, driveshaft, differential, and so on. Yes you could run a 3.73 diff but that's not ideal.

My thinking is that if you are going to the trouble to do the swap, then why put in a 200K partly worn out motor. There is likely to be cam and or rocker wear on a m30 with higher mileage and if you plan on keeping the car I would check everything and at least replace rod bearings, probabbly rings, timing chain, gaskets, head valve seals, and so on. I would also want a new guibo and shifter parts while I'm there. Don't forget a new clutch assembly.

I could cheap out and use old partly worn parts but I would not want to have to tear things apart in a year or so to replace major items. Also by replacing worn parts from the get go you will get the full benefit of the swap performance wise.

The questions I have is how long do you plan on keeping the car and what do want to do with it. If it's a long term keeper then do it right the first time is my suggestion.

For bang for the buck a b35 with a really good cam and exhaust will do a lot if you aren't going turbo.