we are using a 4" crank with EAB heads to put my flathead back together. as i understand it, we should have 0.050 to 0.060 clearance to valves and pistons. (note: we have a new schneider cam with lift of .355 lift. we haven't clayed it yet, but we are thinking we'll need to get our clearance from the head gasket. from what i've seen so far to get a compressed .06 or .07 we need a sandwich type gasket. any suggestions: copper or steel? any brands? we are bored .060 over as well. thanks.

 

I think you'll be surprised, Dick! Have your heads been shaved? (ever) I have what I believe to be virgin EAB heads, and these are the values I got from claying. I have a stock EAB cam, so no concerns about clearance over the valves, but unless your heads are shaved, I doubt you need to worry either. Note that the guys on the Flathead Forum, and my machinist, all said you can take .050" off any stock (unshaved) late model heads and not even bother to check with clay, with a stock cam.

Note the big difference between DS and PS clearances over the pistons. This is because of the banks being at different offsets to the crank, which means the combustion chambers have to be different depths to have equal total volume.

Anyway, I'd say you still need to clay, but I wouldn't use anything but a FelPro or Best head gasket if you can help it.

 

thanks, yet again, ross. we'll def clay them out. it would be nice if we can use the regular gasket. we did have the heads cleaned up to flatten them out , machinist said maybe .008 and same on the block decks. quick inspection on the pistons w/o any head gasket, piston just about touched head. we'll see what the clay tells us.

 

Use plenty of clay, all around the edges of the pistons, and at the center. If any of your old head gaskets are intact (or reasonably so, fire rings intact), use that rather than waste a fresh one. "Just about" may look close to the eye, but I'd bet you have .075 - .080 at least. I decided not to chase after the highest compression, keep in mind just going to +.060" bore raises CR by almost 0.5 points, and with your stroker crank and shaved heads and decks you are pushing 8:0. It should be a very lively engine!

 

exactly, ross. i just wanted to use my 4" in it and my ford heads. i'm not really trying to chase high compression. we'll clay it soon. thanks. dick r.