Petter Pins

You're quite right Tom, I didn't express myself very clearly there, but that was the gist of what I was trying to say :-) In fact, due to the arcane RAC horsepower rating formula we used to have in the UK, engines tended to have small bores and long strokes. The little pistons had to whiz up and down at great speed, with lots of side thrust at the extremes of the stroke. Thats also one of the reasosn why for many years an engine would need to rebored at only 20-30,000 miles :-(

Regards

Philip T-E

Good point Martin,

I'd still like to know what they originally used - the steel clasifications (EN Nos.) that we know and love (and have been obsolete since the '70's) came into being in the '40's. Were there equivalent standards before this or were pins and the like just unreliable?

Mark

The drawings simply call for "best mild steel", they have a thick case and are reliable. After 80 years or so most are simply worn out. Not much help to you I fear. regards Roland

clasifications