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Old 03-25-2021, 03:30 PM
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tgreese tgreese is offline
Join Date: May 29, 2003
Location: Medford MA USA
Posts: 11,460
Originally Posted by FSJunkie
Thin cylinder walls causing overheating is a common thing that one hears in chat circles at car shows, but the laws of thermodynamics and materials science don't support it, nor does my own experience with plenty of engines that I drove when they were standard bore and drove again with a .030, .040, or even .060 overbore.
Perhaps you don't understand that a typical block from an engine like the 360 or the 258 starts off with more iron in the walls than a 401. In the 401, the bore diameter is large compared to the bore spacing, and something had to go. Big block displacement from a small block geometry.

I don't understand how you can appeal to thermodynamics. There is a fixed amount of heat created in combustion, but there is no rule for how much of that heat diffuses through the cylinder wall versus how much leaves with the exhaust gases. It seems clear that the same heat gradient across a thinner cylinder wall would transfer more heat to the coolant.

Sorry - none of this helps the OP with his original problem. I would say add as much additional cooling capacity as you can, to stay ahead of the thermal load. If this does not work, one could sleeve the cylinders to the factory diameter. That would restore the factory cooling performance, at a cost of about $100/hole plus parts.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS, hubcaps.
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Last edited by tgreese : 03-25-2021 at 03:47 PM.
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