enyone knew what exactely volume have the M50B25 stroker head ?
of if the piston reach the block upper side at TDC ?
I intend to make a "engine arrangement", using a M50B20 block, fitting some M50B25 pistons and a M50B25 head ... I suppose that this setup to increase displacement to 2.2l, but I'm completely lost in CR calculation (the engine will be turbocharged, so, the resulted CR is a big concern ...)
thank you

When I had the machine shop CC my M50 non-vanos head, it was 33cc. I was told by someone on this forum that it was supposed to be either 32 or 34 ccs, if that gets you in the ballpark.

ouch, this is no good at all for my calculations :(
I supposed that the M50B25 head volume is bigger than M50B20, but seems to be the same ... probably the piston don't reach the block upper side making bigger combustion chamber ..

When I had some head work done I had them measure each combustion chamber. Each one came back at 32 cc's.

ok, so, i"ll done the calculations (please correct me if I'm wrong):
head volume = 33
displacement = 2.200 cc (M50B20 crank + con-rods and M50B25 pistons)
2.04mm (stock specs - first reparation) HG volume = 11.3 cc
new CR = (displacement + combustion chamber)/ (comb chamb) = (366.66 + 33 + 11.3)/(33+11.3) = 9.27:1;
if the head volume is 32 cc, then the new CR = 9.46:1;
i think that in both cases, the 16-18psi of boost can be reached
in these supposition, was considered that the distance between pins and top end of the pistons are the same for M50B20 and M50B25 ...