cam question

[The Humjet]

hi, i just bought an m20 engine out of a manual 323i and before i drop it in i want to build it up and i thought on starting on the head first, and i have looking for some cams for my engine and all I can find is cams for the 325i.
I was wandering even though the heads are different could the cams fit both types heads

[call me jack]

it's possible... try to find out what the casting is... i know the 200 casting (325 eta) can be redrilled to fit cams designed for 885 heads (325i)... a machine shop might be your best bet to ask...

[The Humjet]

See I've seen people put cams onto their 731 heads, where did they get them from or could they have machined the heads to fit the cam. With all the different cam specs will it still work the same way

[nando]

all M20 cams are interchangeable, just make sure all 7 cam bearings are drilled, which they should be on a 731.

[The Humjet]

Beauty happy with that looks like I'll be ordering that next

[DmcL]

any idea what the effect of fitting an M20B20 cam to an M20B25 would be? i hear the 320i is meant to have higher lift but im guessing shorter duration? any ideas how this would affect a dyno graph? more torque less hp or more hp less torque?

i have a sneaking suspicion that when i replaced the cam in my 325i i may have unknowingly fitted a 320i cam.

[nando]

probably less power and torque.

[DmcL]

any idea if theres a part number stamped on the cam anywhere? dont remember seeing one when i changed the cam.

[nando]

M20b25 cams have a "K" stamped on them