The Stovebolt Site Forums The Shop Area Engine Shop To bore or not to bore a 292 beyond 060?

I have a 292 that has been bored to 060 and would like to keep it but was wondering what problems I might encounter if even feasible?

Thanks!

I've seen more than one Model A Ford engine bored to 125 thousandths oversize, but have no idea how far you could go with a 292.

It might handle an 80 overbore, but be very sure you have a very good condition cooling system. Those cylinder walls will be pretty thin. If you're determined to keep using that particular block, sleeve all the cylinders back to standard bore, using sleeves with 3/32" wall thickness.
Jerry

When these engines (194,230,250,292) came out in 1963 they were called "thin wall castings" so it might be wise to have the cylinder walls sonic tested. We raced with a 292 powered circle track car that was very competitive but had a problem with #1 cylinder fracturing. When Mercury Marine started to use them in boats they corrected this problem. A sonic test is cheap and might reveal a thin spot in in just one cylinder which could be sleeved and that is less expensive than doing all six.

Can you even get bigger pistons for a reasonable price? Sleeves are expensive, might be worth look for second block.

The sleeves aren't all that expensive- - - -the machining to install them is. I salvaged a lot of my competitors' "worn-out" blocks by sleeving all the holes back to standard bore, until some of them figured out they were getting beat by their own junk! All the other machining was still in good shape on those blocks- - - -the line boring, decking, etc.- - - -they just figured a 60 or 80 over block was not useful any more. I bought those blocks for pennies on the dollar (or they gave them away) and I used them for training my students how to bore cylinders. The end result was a good supply of round track engine blocks at very low cost.
Jerry

Maybe you can explain that statement to me Jerry.
I have been hearing this since I was a kid and do not understand it.
I do understand that a larger bore will create more heat(more fuel, compression etc), but thinner cylinder walls seem to me would just transfer heat through to the water faster.
I don't know why I never talked to my dad about this while he was alive, as he was a physics teacher.
What say you, or others.

Since cast iron transfers heat very quickly, and combustion temperature can approach 2,000 degrees F. (confirmed by my measurements of exhaust port temps during dyno runs) cylinder walls thinned by big overbores tend to transfer a LOT of heat to the coolant during heavy throttle operation. Once it gets to the coolant, it MUST be dissipated by the radiator in a hurry. It's not uncommon to see some flash boiling around the cylinder walls unless there's plenty of coolant flow from a very efficient water pump and a high pressure radiator cap to raise the boiling point of the coolant somewhat. I grew up around flathead Ford round track engines bored .250" oversize and stroked 3/8", running 11:1 compression and alcohol/Hydrogen Peroxide fuel, and one of our biggest problems was keeping the things cool! Dad usually ran radiators from F-8 Ford dump trucks on the race car. When I ran dirt track 327's in the mid-1970's with 60 or 80 overbores, we always ran big radiators and 21-lb. radiator caps.
Jerry

Jerry is spot on, with thin cylinder walls the heat gets into the coolant faster than the radiator can exchange it. A very free flowing exhaust will help with large over bores since about 85% of an engines waste heat leaves via the exhaust system but there is a point of no return between heat generated and heat expelled. We raced Hudsons with no heat problems but the flathead Ford guys had some exotic (and some ingenius) ways to get rid of heat. Cowling (flaring, baffling) also needs to be where all the incoming air is directed through the radiator and the heated air has a no restricted path to exit the engine compartment. Splash pans along each side of the engine may have to be removed and sometimes the inner fender will have to be louvered. It's not called a cooling SYSTEM for no reason.

Thanks for the input everyone! I have a short block with an 040 overbore that I will use but will hold on to the 060 block for possible sleeving in the future.