Boring a 292 beyond 060?

[Dongray]

Has anyone bored at 292 beyond 060 and if so any problems? I just bought one that is in overall good condition but it's already at 060 and I was wondering if I could get one more bore out of it someday.

[Clyde65]

Why not sleeve it?

[kazoocruiser]

Originally Posted by Dongray

Has anyone bored at 292 beyond 060 and if so any problems? I just bought one that is in overall good condition but it's already at 060 and I was wondering if I could get one more bore out of it someday.

Where would you get rings for it?

['68OrangeSunshine]

It seems GM thin-walled the L25 blocks in order to save weight. So boring beyond .060 over is sketchy. Leo Santucci said he considered .060 the practical limit for L6 292s. He also said the later Mexican blocks could take a larger bore.
He does list a chart of larger bores:

OVERBORE....................030-----.060.-----.080------.090----.100----.125

BORE SIZE................... 3.905----3.935----3.955----3.965---3.975---4.000

CID............................. 296------301------304------306-----307------311

[From ''Chevy Inline Six Cilinder Power Manual'' by L. Santucci. C. 2002]

Board member Keith Seymore, who worked on the Chevy Truck production line, claimed he had a 292 bored out to 308 inches. You might PM him about how he did it.

['68OrangeSunshine]

Originally Posted by kazoocruiser

Where would you get rings for it?

Hastings.
Total Seal has rings in that range. Keith Jones, their tech rep, told me it was really up to what the machine shop found out about that specific block. Best path would be to clean up the bore as little beyond .060-over as possible, then stop there. Ross can make custom forged pistons for any size. Total Seal can make rings for any size piston, including .080-over.
Members of Inliners International get a 10% discount on Ross pistons.
www.inlinersinternational.org