Thanks again for the reply – the bore is between 73.03mm and 73.06mm diameter at the bottom of the skirt which makes it a STD bore by my data. djcb, i’ll drop you an email.
The engine is an early Birmingham one with the Lucas dynamo and I can quite imagine it is comprised of some Shipley parts. The block and head are not clubmans type but the pistons could well be based on the need to use up stocks. In fact the engine is in remarkably good condition considering it hasn’t run since at least 1970, but there is evidence of mild seizure in both bores and the rings have gummed up and begun to corrode. The gumming was so bad that despite several months of spraying wd40 and extreme patience onto the rings i broke 2 out the 3 on the right hand piston, and haven’t even attempted the left hand one yet ! I’m going to take a bit of a risk and not strip the engine any further and try and get it running again once the rings are replaced.
Cheers,
Paul
