7.3:1 cr with squish on a 1380
Turbo Mini Forums

Had a look in vizard book last night......Bit on chamber volumes of different heads,some 1000cc heads seem large to start with(28.3cc)




So I been doing a bit of measuring today I found a old 1000cc head (a plus I think) and found the chamber depth to be 12mm(all my 1275 heads are 8-9mm),If the chambers are milled out round at 1000cc piston size(67mm)This will give 42cc chambers
And a 3.25 mm wide squish band to match the 11cc dished pistons(73.6mm)
Valve sizes will need upping abit from 25/31

UPDATE
Had a bit of a play-found the water jacket under the beak so rebuilt it with blu tak,took the spark plug side out to head gasket size and got 35cc ish
9" disc cutter next to have a look at thickness

Edited by Dangerous on 22nd Jan, 2005.

Metro turbo weekend driver,Mini turbo in the making again!

Why do this? The head's ports are so small that even if you get your CR down, you sure wont get sufficient Volumetric efficiency to fill the cylinders. If you try to modify the head, you'll see the limiting potential.

Try fitting the head on a 998 instead, and you can have 6:1 compression ratio and run 40psi.