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Old 03-23-2021, 02:38 PM
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tgreese tgreese is offline
Join Date: May 29, 2003
Location: Medford MA USA
Posts: 11,460
You guys understand that thinner cylinder walls transfer heat to the coolant faster? No personal experience with this, but there has been plenty of discussion about 401 engines that run hot after they are overbored for a rebuild.

I would point out that the core alignment in the cylinder block varies for each block. You could - hypothetically - have a badly aligned core that can't tolerate 30 over, and a well aligned core that will go 60 over. There is a sonic test for this, which I would recommend for every 401 that's a candidate for an oversize bore. I don't have any idea what that thickness should be - though this has been covered in earlier posts; cylinder+wall+minimum+thickness
Tim Reese
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