another head question

[IMJ]

A few years ago I purchased 1557570 R1 heads that had R3 valves installed by a Studebaker vendor. I originally planned to install them on my R1 Lark but never got around to it. My new plan is to turn my engine into an R2. I do not want to change to dished pistons. I know the 1557582 R2 heads are 67cc while stock 1557570 R1/V-8 heads are 54cc. My heads with the R3 valves actually measure 58cc. In order to get my compression to where it needs to be to add a supercharger I need the volume in the cylinder heads to be close to 67cc. I can gain about 2cc by using a head gasket that is thicker than the shim but thinner than the composite gasket. That means I still need to remove 7cc of metal from the combustion chamber.
My question is could someone tell me the purpose of the raised sharp edges or shoulders around the valves. I circled the area I am referring to in the one photo. Would it be detrimental if that area was removed or rounded off? For comparison 7cc is approx. equivalent to 1 teaspoon. I don't know if that area if removed would increase my volume 7cc. Thanks for any and all comments and suggestions.

regards,
Jay

[okc63avanti]

LARGE PICTURE WARNING ...

For comparison here are some close up picture of my R1 heads ported by Michael Myer. I haven't measured them but Michael said something like an extra 10cc of volume.



My car is also receiving hypereutectic pistons and a Paxton supercharger. Michael believes compression ratio will be in mid 9's.

[Mike Van Veghten]

Do one thing if it hasn't been done.
The "eye-brow" area opposite the spark plug....lay that back to a 45 degree angle around both valves and heavilly blend ALL of the sharp edges.
Do not radius it like some do, cut it back to a 45 off of the valve stem center.
Be carefull around the seat areas.

That will do two things, it will make the chamber MUCH more effecient, it will also lose the CC's you require to loose.

Mike

[64Avanti]

The purpose of the ridges is to restrict air flow! Do as Mike said!

David L