m30 engine manifolds (e23)

Are all e23 M30 engine exhaust manifolds the same regardless of size (2.8 to 3.5) or do they differ substantially?

Thanks

AG

They're all the same mate from 2.5 to 3.5, the only
difference being the engine capacity stamped on the
bit in the middle and sometimes the size of the inlet
hole where the throttle body bolts on. Some 2.5/2.8
manifolds have a smaller hole to match the smaller
2.5/2.8 throttle body but most of them have the bigger
hole like the 3.2/3.5. All E28/E23 M30 heads are the
same too - 2.5. 2.8, 3.2 and 3.5 all have the same
head with same sized ports and same valves. It's
only when the E32 came out that the ports and
valves were made bigger along with the E34 and
Highline 635CSi.
An Alpina head will have been opened out along with
the inlet manifold. Bigger throttle bodies from the 3.2
and 3.5 cane be fitted to a 2.5 or 2.8, don't know what
power you'll gain though. But seeing as you're only
going to pay a few quid from a scrapyard (the E32
and E34 3 litre and 3.5 t/bs are the same) it's be
worth doing. Get the big rubber inlet hose to the air
flow meter though.

Edited by Andy Boy

I was, but that's good advice Andy.
Thanks
AG

alpina manifolds that ag has, would sound and look nice on robs e23

Andy Boy wrote: ...I just threw away a perfect 735i E23 exhaust manifold too.

You really do like rubbing it in, don't you?