The Ford Barn

Seth Swoboda · 03-20-2023, 07:26 PM

I have a 37-38, 21 stud, 221ci engine that is currently at .080 over bore. Four of the cylinders have some scaring in them that will require another overbore. The engine is otherwise very nice.

I would like to bore the engine .125 over. This would make the new bore size 3.1875, the same as a standard sized 59A engine. Pistons and rings would be easier and cheaper to acquire.

The question is the head gasket. What are you guys doing for 21-stud head gaskets on a .125 overbore?

**Let's also assume that the cylinder wall thickness checks out okay for the .125 overbore in this case.

03-20-2023, 07:26 PM	#1
Seth Swoboda Senior Member Join Date: May 2010 Location: Southern Illinois Posts: 3,833	1937-1938, 21 stud engine bored to .125 I have a 37-38, 21 stud, 221ci engine that is currently at .080 over bore. Four of the cylinders have some scaring in them that will require another overbore. The engine is otherwise very nice. I would like to bore the engine .125 over. This would make the new bore size 3.1875, the same as a standard sized 59A engine. Pistons and rings would be easier and cheaper to acquire. The question is the head gasket. What are you guys doing for 21-stud head gaskets on a .125 overbore? **Let's also assume that the cylinder wall thickness checks out okay for the .125 overbore in this case.