Piston help

[tsholin]

Does anyone know what the difference is between the CA77 and CB/CL77 pistons? The CA pistons seem to be more readily available than CB/CL pistons so I was wondering if they are interchangeable.<br /><br />Thanks.

[LOUD MOUSE]

As I rebuild about 10 of the 305 (Dream and CB72/77) engines a year I was curious why the Dream has less compression than the CB/CL77 engines. I had a Dream and a CB77 piston on the work bench side by side and the Dream one looked as though it should actually give more compression than the CB/CL77 one. I did a couple of tests with liquid with the pistons (rings on both) in a cylinder and found that the Dream took less liquid than the CB/CL77 one (APX. 1.25cc). So then I took a 305 Dream head (fresh valve job completed) and a CB/CL77 head (fresh valve job completed) and did a liquid test. Well the Dream head takes about 1.75cc more liquid than the CB/CL77 head. So I now think that the Dream piston will actually up the compression when used with the CB/CL77 head and I don't think there will be any adverse effect. The Dream pistons are cheaper and I have lots of the oversize ones. The rings are sort of expensive but when used with the Dream pistons lowers the cost some. .............