Board index Flathead Power-Technical Questions, Answers, and Suggestions Big Twin Flatties "hogged out" cylinder head bolt holes

"hogged out" cylinder head bolt holes

Post Sat Apr 07, 2007 2:06 pm

Posts: 42
Location: seattle, washington
hi all, got a set of BT aluminum heads that were drilled out to a big 1/2" size hole, as they were used on a cylinder set with 1/2" head bolts.

I want to use these heads on cylinders with 7/16 stock bolts, should i be concerned about the hole size difference, will the heads leak around the bolts??

building small sleeves will be hard, what about studs, any recommendations will be nice, as i am worried about head leaks around the bolt should i be??.

thanks.


Posts: 6
handshifter wrote:
hi all, got a set of BT aluminum heads that were drilled out to a big 1/2" size hole, as they were used on a cylinder set with 1/2" head bolts.

I want to use these heads on cylinders with 7/16 stock bolts, should i be concerned about the hole size difference, will the heads leak around the bolts??

building small sleeves will be hard, what about studs, any recommendations will be nice, as i am worried about head leaks around the bolt should i be??.

thanks.

Measuring the hole in a new copper gasket with verniers gives .498 to .502 Since the hole is well "inside" the "embossed" sealing ridge, I think it`ll fly the way it is. JMO and I`m no expert!

OR, maybe a thin copper washer 7/16ths I.D. UNDER the stock steel washer for additional insurance.


Return to Big Twin Flatties