I received an email last week from John Warr of Warr's HD in London. Seems he scored his piston on his 1914 single during the veteran run last summer. He was shipped a new alloy one recently but some of the dimensions didn't add up to what the old one measured at. I dug out a few things and measured them for him and thought they might interest some of you.... I had both early and late (Post 1924) 61 c.i. pistons, the ones in the photos are the early ones. The piston pins actually use cotter pins as keepers!
John's Piston. He needs a .060 over one...
Hey! look what I found in my stash!
Pinton pin diameter .610
Piston pin center to crown 1.830
Here is a real rare part! A factory original racing cylinder blank-off plate, and a 61c.i. compression plate. Compression plates were used to turn a solo engine into a sidecar version. 74 c. i. plates are pretty common, but 61's are pretty tough to find these days.
Just shy of .100