The Ford Barn - View Single Post - How to Increase compression on 1937 Flathead

Ol' Ron · 03-22-2023, 01:03 PM

This is very easy after you do it several times. Measure the clearance above the valves when they are opem. Add .050" this is measured fron the deck. Now measure the deoth of the valve pocket. Subtract the previous number that plus the thickness of the head gasket is tha amount of material you need to remove. Don't remove more than .070" forgot why. Place the head in the mill. If a broach just shim the side you want to mill off, Chamber size wil be reduced by aprox 10 CC (Depends on original heads. Not recommended for Late heads, very thin at the top).
I may have missed something here, but somebody will probably catch it and correct me, I hope
Gramps

03-22-2023, 01:03 PM	#7
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,985	Re: How to Increase compression on 1937 Flathead This is very easy after you do it several times. Measure the clearance above the valves when they are opem. Add .050" this is measured fron the deck. Now measure the deoth of the valve pocket. Subtract the previous number that plus the thickness of the head gasket is tha amount of material you need to remove. Don't remove more than .070" forgot why. Place the head in the mill. If a broach just shim the side you want to mill off, Chamber size wil be reduced by aprox 10 CC (Depends on original heads. Not recommended for Late heads, very thin at the top). I may have missed something here, but somebody will probably catch it and correct me, I hope Gramps