Small end size.
Posted: Sat Jan 26, 2008 4:51 pm
Hi Folks.
All the OHC engine details I have seen, including the Hepolite piston catalogue, talk about a 9/16in dia piston gudgeon pin, and a 36mm compression height.Hepolite number RS7759 and RS7811. Later than 1933 engines have a 15mm gudgeon pin and 25mm compression height.RSW11578. I have a spare block, which came with its pistons. That has 15mm gudgeon pins and 36mm compression height. The matching con rods also have the normal pinch bolt arrangement, but for a 15mm pin. It is a 1930 engine. Can anyone throw any light on this, and why are these pistons not shown in the Hepolite catalogue? Thanks. Roger.
All the OHC engine details I have seen, including the Hepolite piston catalogue, talk about a 9/16in dia piston gudgeon pin, and a 36mm compression height.Hepolite number RS7759 and RS7811. Later than 1933 engines have a 15mm gudgeon pin and 25mm compression height.RSW11578. I have a spare block, which came with its pistons. That has 15mm gudgeon pins and 36mm compression height. The matching con rods also have the normal pinch bolt arrangement, but for a 15mm pin. It is a 1930 engine. Can anyone throw any light on this, and why are these pistons not shown in the Hepolite catalogue? Thanks. Roger.