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MadaboutKitcars

This is a read-only archive of the old Madabout Kitcars forum. New posts and replies are no longer possible, but every thread is still here to browse and read.

M20B20 Head

1 Apr 2010, 2:27pm
I noticed one for sale on Ebay. I beleive it is for the 320 engine. Does anyone know the differences between that and the head used on the 325? It might make a useful spare....

Robin
1 Apr 2010, 4:27pm
I don't think it'll work Robin - aren't the cylinder bores different between the M20B20 and B25?

http://en.wikipedia.org/wiki/BMW_M20

Reading from that, yes it does (80 vs 84mm) - so I guess at TDC the piston would be smacking into the head.
1 Apr 2010, 5:41pm
it will go on but stuff like the ports and valves are smaller, its not worth doing. Better get an 885 head if you need one :)

The rods are short on the B20 - 130mm instead of 135mm on the B25. You can mix and match bits to make a 2.7. I'm actually using the B20 rods in my 2.8.