Ok guys.New flathead owner here. For reasons of authenticity Im changing from Offy to Fenton heads.The Fenton heads that I have look nice with no visible problems.The 8BA was a good running,quiet engine.How do I know that these heads are ok?I would like to just slap them on.But I know that that might be asking for trouble.Have these heads been surfaced/milled?Are the combustion chambers to small?etc,etc. HELP! I have tried to find this thread but was'nt successful.
I can't quite understand how Fenton heads would be more authentic than Offy heads. Also I've always been one of those who feel that If it "ain't broke, don't fix it". About all I can say is that you would have to get both heads side by side and cc the combustion chambers to see what you have. Probably somewhere in someone's archives there is a chart telling how to check the Fenton heads measurement wise. One thing though. If you were to dig through a stack of 49/55 Hot Rod Magazines 75 percent of the flathead powered rods in the magazine feature sections ran Offy heads.
You could have local machine shop check them for cracks. Better to find out before than after. I think CC-ing them will be the only way to know for sure.
You'll need a straight edge and feeler gauges. Check for warpage straight and diagonally across the mounting surface. A wide depth micrometer to check the chamber depth will be the best way to tell if they've been milled, providing you can find the stock specs. If you can't and they're straight, try mounting them with a bit of clay on the piston top and slowly rotate the engine by hand. Remove the head again and see how much the clay squished, it'll give you an idea of your clearance. Flatman
Thanks for the replies guys.The authenticity issue is related to the particular car that i'm cloning.That car had Fenton's.I'm hoping for more info.
I found this: http://www.jalopyjournal.com/forum/showthread.php?t=134841 It shows the original compression ratios.
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