Is it feasible to swap a head (and intake manifold) from a '91 735i m30b35 to an '86 535i m30b34? Could the intake from the '91 735i fit the '86 535i with it's original m30b34 head? I have a chance to get the head and intake from the 735i really cheap with no problems on them. I looked on the main parts site (realoem.com) and Googled everything I could think of. I believe the intake may allow more air and seems to be a little more compact. Thanks in advance.
These are pretty similar. The intake should swap over OK, but the valve cover is different as the later one has a mount for the air flow meter and a totally different airbox.
I'm less sure about the block. I THINK it'd work but I know the part numbers differ. Be interesting to see if they take the same head gasket part number, that'd be a good indicator.
I doubt that. It's an almost identical casting. On euro cars there's no big difference between the two car's compression ratio. But there may be on the lower compression US models. This could just be down to the pistons, but the head may differ too.
In the first instance, you're looking at lower compression, so your power will drop unless you're also planning a turbo installation, in which case you might want lower compression.
In the second instance, you're looking at a different Motronic injection system, so you'd need to swap the computer and wiring harness for the engine as well. This has been done and, together with higher compression pistons in the M30 block, you'll pick up some power. You can accomplish the same in under a half hour with a chip ...
If your head isn't broken or leaking, don't go messing around with this swap just for grins. You won't like it. Read more on it over in the
I'm too "old" for doing the changes-for-grins action. LOL. I was just getting the group's feel for the possibility. I already Conforti chipped mine and get the same power as the standard m30b35. I figured you guys would know more or have done it already. Thanks for the tips!
Bill in Omaha
Yes, but ...
Yes, but ...
In the first instance, you're looking at lower compression, so your power will drop unless you're also planning a turbo installation, in which case you might want lower compression.
In the second instance, you're looking at a different Motronic injection system, so you'd need to swap the computer and wiring harness for the engine as well. This has been done and, together with higher compression pistons in the M30 block, you'll pick up some power. You can accomplish the same in under a half hour with a chip ...
If your head isn't broken or leaking, don't go messing around with this swap just for grins. You won't like it. Read more on it over in the
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