y block pistons hold up well as a rule.top groove wear isnt usually a problem.even when i have an engine bored i often use used oversize pistons.very few shops still cut the top groove for the spacers most got rid of the equipment for doing it.

I am suprised a motor with 40,000 needs a rebuild with a over bore but since I think they are from a 63 292 that tells me they are from a truck and its probably 40,000 very hard miles,I wish I lived closer so I could check them out but I have changed plans again on the motor and not going to tear apart the 272 and will be going with a 292 that has been bored but never used and will use the rotating assembly from the 62 292 I have to build a motor.

Butchering up everything I can get my hands on in Dayton Ohio

Going back to what RayCarter originally posted, he stated that the pistons he is looking to sell were removed from an engine with 40,000 miles of operation and there was no cylinder ridge needing to be removed to permit the piston and rod assembly removal.

I'd certainly consider the used pistons if I was looking for a set of stock bore 292 pistons and was trying to make the buck do as much as possible.

As Jeff's machinist suggested, the pistons need to be looked at and checked to determine their condition. Perhaps RayCarter might consider offering some type of return option if after shipment and inspection, they are found to have skirts or ring lands that are not in as good shape as 40,000 miles of use would suggest...

Lord knows rebuilding an engine does not necessarily require ALL new parts. And some of the new parts available today, may not be as good as the old parts!

NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

junkyardjeff,

I have new pistons which are std, 30 and 40 over.

New pop uppistons and a set of boxed nos rods.

Also have a set of pistons which are mounted on a set of resized, bushed rods, ready to go.

If interested email me at motorcarinvestments@gmail.com

Happy Easter to all.

John

Is this the worlds first exotic automobile? The 1935 Harris fwd speedster, No heavier, higher, wider, taller or longer than an AC Cobra, but many many decades before.

http://www.autopuzzles.com/forum/index.php?topic=11958.0

I was interested in them until I talked with the guy that will be doing my machine work,he told me if I cant personally check them out and measure them to pass and buy new.

Butchering up everything I can get my hands on in Dayton Ohio

I agree with Paul. If the bores in the 292 NEED to be overbored, there has got to be wear to the original pistons that moved in those bores.

Piston skirt wear has been mentioned, and can take the form of scuffing or scoring. Also, the diameter of the piston skirt may be reduced from normal wear. The piston skirts can be knurled with an X pattern (commonly called 'diamond' pattern) to expand them to compensate for skirt wear.

In a high mileage engine, the top ring groove often incurs significant wear as well. This is a because it is nearest to combustion chamber temperatures and pressure as well as all the airborne abrasives that may enter the engine.

Perfect Circle (for one) made a go no-go gauge for checking top and second ring groove wear. If the gauge went into the groove far enough to hit its 'shoulder', it indicated that the groove was oversize by .006 or more. If the top groove was oversize, the correction was to re-machine the top groove, add a top groove spacer to take up the material removed by the manual machining operation, and then re-ring. The Perfect Circle tool for re-machining the top grooves was called a Manulathe. The Manulathe used three locating pins that fit into the second groove to assure the top groove being re-machined in the same plane as the original groove.

IF there was a ridge at the top of the cylinder that had to be removed to take the pistons out, I'd bet the top ring groove needs resizing. Probably because of labor costs today, for passenger car applications, most worn pistons are replaced rather than re-machining top grooves or expanding piston skirts by knurling to adjust fit in the bore.

Much to evaluate in re-using 'pre-tested' (spelled USED) engine parts.


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

But you can always get a worn 272 and bore it to 292.


Hyvinkää, FI

Ray. Paul brings up a good point. If you can state the condition or the mileage on the pistons, it may help to generate a sale. Posting a picture of the pistons may also help.

Lorena, Texas (South of Waco)

Ray: You don't say but, I presume these are the used pistons from your stock bore 292?. Presumably, since the engine is 50 years old, and needs a re bore, the piston skirts & so on are likely well worn, which is likely why you aren't getting any apparent interest...

Paul

I still have the 292 pistons standard size if anyone is interested shoot me a fair price I might accept it. Thanks