On Tue, Sep 21, 2021 at 8:09 AM GP O <
[email protected]> wrote:
Dave, I have a Norton Mk3 and may need boring. I contacted Andover Norton and they said that the machinist must have the piston to match to the bore. Will any local machinist follow this practice? If no, Will you take this project. Thanks, Gary
On Tue, Sep 21, 2021, 1:16 PM David Comeau <
[email protected]> wrote:
It's quite interesting that AN can give information like this, yet manufacture new cylinders without supplying said... pistons.
Why do people assign them such credibility is beyond me...
The big joke is a piston manufacturer should absolutely know the pistons alloy rate of expansion. Then pistons melt around 1300deg which sets a limit. Then make the piston to match the known published bore or it's oversize.
What makes you think the boring bar operator knows the expansion rate of various cast/forged alloys and can adjust accordingly. Can't the piston engineers do the job correctly? Std/+10/+20/+30 etc. size is a well established and published number..
Yes most machine shops want pistons in hand. then THEY determine the clearance, possibly using a Ouija boards or confer with a secret society?
Sorry not taking in any new norton work.
GP O
1:45 PM (32 minutes ago)
to me
Ok, thanks.
