Piston Ring question

[mike J]

Jock, are you saying that you had your cylinders bored before you got your pistons? That's a big no no!!! There's no way to know what the bore should be without measuring the pistons. I bore cylinders all the time but I won't do it without pistons to measure from. Mike J

[Billy Ricks]

Mike,
I have a set of Cosworths and a couple of extra blocks. One of the blocks has a piece of one liner busted off so one liner needs to be taken out of one a dropped into the other. Would you be willing to do the work? The cylinders shouldn't need much more than a clean up. The pistons are only .05mm over. That's not a mistake, .05mm is correct. They were one off pistons made for a bike Britt Turkington used to race. They are brand new pistons and I have Total Seal rings for them.

[mike J]

Billy, that job shouldn't be a problem. The .05 over size is nice because it gives you an allowance to hone on the stock bores. All I would need to know is the recommended skirt clearance for the Cosworth pistons and where they take the clearance measurment from. PM me with your number and we can discuss it more if you like. Mike J

[Big T]

Once you're down to the cases, it's pretty easy to just keep going and split the cases and replace the cam chain. That way you can check the tranny for unusual wear and clean the goo out of all the sumps

Warning, you will be tempted to start cleaning, polishing and painting everything before you put it back together so it will look like new!

[Jock]

Hi Mikej,

Happy New Year to you all at GS Resources.
Sorry for the delay in replying, work seems to be in 6th gear and at full throttle.
Anyway to answer your question it seems I jumped the gun a bit, they waited until my pistons arrived prior to reboring them. They told me it its a tight tolerence of 0.05 to 0.1 thou they opted for 0.075 as an optimum clearance. Things are going well so I hope to have her at least running soon.