I have one to put in a engine I am putting together but as you have found there is not much info on it. There was mention that the way Shrick and Catcam list the specs that it is closer to a Shrick 272. I didn't get a timing card or anything with it as I picked it up new but second hand so hopefully...

Jhonno wrote:There is somewhere on the forum a graph with the lift/duration plotted from the 3 M20 cams.. I'll be buggered if I can find it though..

This the one?

i got 206.2mm again on my B25 block. I believe this engine has not been rebuilt so am confident that is the original number. The way i measured was from the machined top deck surface to the machined face that the main caps are bolted to. I assumed these were accuratetly machined on the crank centre...

The blocks are the same it is the stack height that everyone gets confused with deck height. :wink: To expand and clearify this a bit You hear the block heights of 206.7 for an B25 block and 206.2 for an B27 block If you add up the stack height: 1/2 stroke + rod length + Piston Compression heigth 4...

The blocks are the same it is the stack height that everyone gets confused with deck height.

for a 2.5 block Block height 206.7mm For the M20B27 block height 206.2mm Careful using this as the block deck height as it is actually the stack height. You need to use 1/2 the stroke 44.8mm (1/2 89.6 stroke) 130mm (rod length) 34.2mm (2.5 Piston CH) --------- 209 (stack height) - 206.7 (2.5 stack ...