Mythbusting, M42 head on M44 block?

[IlovM42]

hi people.
After searching on the net I haven't found any answer.
I know that cometic or other brand like that do head-gasket that work with M42 AND M44 and knowing that M42 and M44 are more or less the same, there is a lot of chances that an M42 head work on an M44 block no?

can't find any post about this.

if you have ideas about it.

thanks in advance.

[hootis]

I am also curious about this as i have an m44 block and m42 head. i read on e30 zone that the m42 and m44 block are based on the m20 (correct me if im wrong) and says that any of the blocks could be used the repair any of the engines. im just worried about having to convert to that ANNOYING serp belt system on the newer m42/m44.

[dsm2002]

Cristian G in Oz on this forum did the M44 head on a M42. His posts cover this. I suspect the other way would be easier. I'll probably be tackling this, M42 head on a M44 block, soon as well.

[wazzu70]

It should be fine.

I wonder though if the M44 head is not better. The follower system is similar to EVOs and other high revving engines. I dont think anyone has pushed them hard enough to know.

[IlovM42]

well M44 system involve more parts so I doubt it will be better than M42 one that are simplier when speaking of reving.

and maybe it's for that reason M44 are set to 6500rpm max and M42 6800?

[colin86325]

I think the M44 head offers less friction losses than the M42, according to the BMW literature.    I can't speak to the rpm limits of the M44 design though.