Thick head gasket needed

[Tom Wesenberg]

I would use the shim and gasket and spray all the surfaces with Copper Coat. I bought a Model A engine about 7 years ago that had two head gaskets and ran fine on the stand. While cleaning out the pan though I did discover the cylinders all had grooves from missing wrist pin locks.

 

[TDO]

ON facing off the top of the piston. Just how thick is the top of the piston and just how much could you safely take off. I have 4" piston in mine not sure of the brand name, but came from Snyder's. Looking thru the spark plug hole. I can see about half the chamfer is above the block. I wouldn't think you could take off enough to do you any good. And still be safe.

 

[hardtimes]

ON facing off the top of the piston. Just how thick is the top of the piston and just how much could you safely take off. I have 4" piston in mine not sure of the brand name, but came from Snyder's. Looking thru the spark plug hole. I can see about half the chamfer is above the block. I wouldn't think you could take off enough to do you any good. And still be safe.

Hey TDO,
I have the Snyder .030 pistons in one of my B engine. I , by hand sander and a heck of a lot of work, took each piston down till it was FLUSH with the block surface..maybe .032 each. I've run this engine hard since and never a problem !
On my other B that has yet to run, I have Egge 4" pistons. The builder did not follow instructions/plans for piston 'compression height' of pistons when ordered. Therefor, he had to machine approx. .032 off of tops of each piston to make them flush with deck , as necessary to run my 7.5:1 Winfield. I do not expect any problems from removing that much from the pistons. Your call, eh

 

[Mark in MT]

The original protrusion of the pistons above the deck surface is .031. This comes from the Ford engine prints. You take 1/2 the stroke plus the rod length plus the compression height of the piston to get the total length of the assembly at tdc. 4.25" stroke /2=2.125, rod length of 7.500, compression height of 1.906 gives a total of 11.531. The height of the block is 11.500 from the pan rail to the deck surface, leaving the pistons sticking out .031". This is for all stock, original parts. Some differences can occur, rods that are not machined to 7.500 center to center, the block surface machined to make it flat again, error from the crank grinder in the stroke length (centering up the grinder on the wear of the journal instead of maintaining the original stroke length.) The reason that I know this is, I built a stroker B engine, offset ground +3/8 stroke, using model a rods, 4.00 bore and ford v8 pistons. Took a lot of research to find a suitable piston with the right compression height to make it work without having custom pistons built.