Thread: 302 cyl head print (needed!)

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Have any of you heared of transfer screws. Transfer screws are hardened set screws with a point. Thread them into the tapped hole with a special tool place the header flange stock over the bolt pattern. Hit the flange with a hammer. You now have the desired bolt pattern. Drill a starter hole for the port then die grind to to match the cylinder head. The problem with this type of precision is that the dimensions change with temperature. Headers can get cherry red and the cylinder head doesen't get nearly that hot. The cylinder head has greater mass than the headers so they change temperature at different rates. The holes in the exhaust manifold or header flange are large to allow for this. If you are in school and have access to fancy tools ask your instructor about an inspection machine or ask how to take measurements using your milling machine.

Originally Posted by Louey

The name they go by is Transfer punch set. They vary in cost from 10 bucks up to almost 200. Depending on what you plan to use them on. I've used these for years in many things.
Most of the time, on header flanges, they only have one hole that is to the right size, called a locator hole. The rest are bigger to allow for mis-aligned holes, and heat expansion.
Example of transfer punch set.
http://www.harborfreight.com/28-piec...-set-3577.html

i still lay out two holes.then i have used long body pointed set screws for threaded transfer . laying out the hole and finding center some times work s better then just a transfer punch what bears on this is how thick the pattern is