first over piston size

Farm Shop · Post by **Farm Shop** » Sat Oct 25, 2014 11:39 am

New here to the forum and after finding much useful information I decided to join! I am currently working on a ground up overhaul of a 67 scrambler. When ordering first over rings (.25) do these run in stock size pistons? Because all I can find is stock and .5 over pistons?
Thanks. Fs

G-Man · Post by **G-Man** » Sat Oct 25, 2014 11:54 am

Welcome to the Forum!

Piston rings are matched to the pistons. So +0.25 pistons go with +0.25 rings etc..

Find out what size your cylinders are and whether they need re-boring. Buy pistons to match the bores and rings to match the pistons.

G

Farm Shop · Post by **Farm Shop** » Sat Oct 25, 2014 12:31 pm

Thanks for the reply G-Man

My cylinders will definitely need boring so that's where I will start and fit pistons from there.

Thanks. FS

G-Man · Post by **G-Man** » Sat Oct 25, 2014 12:40 pm

You may need to check availability of pistons before having the cylinders rebored. They are not in plentiful supply and can be expensive. You need to work with your machine shop and bore the cylinders to whatever pistons you can get. Then the rings....

Good luck!

G

Farm Shop · Post by **Farm Shop** » Sat Oct 25, 2014 1:09 pm

Thanks for the heads up.

As I stated in my first post I can find .25 rings but not the pistons. Where as .5 and 1mm over piston and ring sets seem to be readily available.

So I may just order a .5 over set because I can get it and have my machine shop bore to match it.

FS

G-Man · Post by **G-Man** » Sat Oct 25, 2014 1:12 pm

Sounds like a plan....

G

Farm Shop · Post by **Farm Shop** » Sat Oct 25, 2014 1:17 pm

Again thanks for the insight. This is just the beginning of this project and I have a 65 cl as well to tackle once this one is up and running!

Thanks. FS