The Ford Barn

tubman · 09-05-2023, 04:17 PM

Before you do anything, buy, borrow, or steal a known good stock head and check your clearances, over both the valves and the piston crown. You have to know what you are starting with.

Knowledge is power.

Angledrive · 09-05-2023, 05:55 PM

And kids playdough, or grandkids or in my case great grand kids can be used to find clearance issues.

whatdoyouwant · 09-06-2023, 08:29 AM

I used a dial indicator and found my valves are lifting .385". I took digital calipers and a micrometer, and as near as I can tell I have .319" to .350" valve clearance in the head. When I consider a gasket compressed to .050", I would need at least .030 more clearance in the head. .319" clearance plus .050" gasket = .369" space available, and .385 required. Can I safely take that much out of the valve port on the head. I have also found a company the makes thicker gaskets.

tubman · 09-06-2023, 09:05 AM

I think you need another set of heads. It sounds like the ones you have have been milled to the excess, in addition to whatever else they have been through. . I seem to remember you saying that you have "8BA" heads. A good set should be easy to find.

Getting the proper clearance over the piston head is one of the most rewarding things you can do with a flathead, in terms of both performance and personal satisfaction. Making sure you have adequate clearance over the valves is just another part of the process.

I wouldn't put a flathead together without custom fitting the heads.

whatdoyouwant · 09-06-2023, 11:26 AM

It does seem like different heads are the right place to start.

thanks for all

al

tubman · 09-06-2023, 02:27 PM

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I think the "thicker" gaskets are from a place called "Cometic" (or some such).

Once you price them out, a set of good used heads will start to look pretty good.

Ggmac · 09-06-2023, 03:51 PM

Where do you live ?

cadillac512 · 09-06-2023, 06:23 PM

Quote:

Originally Posted by whatdoyouwant

It does seem like different heads are the right place to start.

thanks for all

al

The 8CM heads I have on the shelf measure .385"-.410" valve clearance. With a gasket that'll be over .450". Sounds like your heads have been milled quite a bit.

whatdoyouwant · 09-07-2023, 05:26 PM

I don't know if 8BA heads are the same as 8CM heads, but if they are my heads must have been milled about .050". I will begin to look for different heads.

09-05-2023, 04:17 PM	#21
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,320	Re: 8BA engine Before you do anything, buy, borrow, or steal a known good stock head and check your clearances, over both the valves and the piston crown. You have to know what you are starting with. Knowledge is power.

09-05-2023, 05:55 PM	#22
Angledrive Senior Member Join Date: May 2010 Location: Lakeland Florida Posts: 303	Re: 8BA engine And kids playdough, or grandkids or in my case great grand kids can be used to find clearance issues.

09-06-2023, 08:29 AM	#23
whatdoyouwant Senior Member Join Date: Jan 2022 Posts: 147	Re: 8BA engine I used a dial indicator and found my valves are lifting .385". I took digital calipers and a micrometer, and as near as I can tell I have .319" to .350" valve clearance in the head. When I consider a gasket compressed to .050", I would need at least .030 more clearance in the head. .319" clearance plus .050" gasket = .369" space available, and .385 required. Can I safely take that much out of the valve port on the head. I have also found a company the makes thicker gaskets.

09-06-2023, 09:05 AM	#24
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,320	Re: 8BA engine I think you need another set of heads. It sounds like the ones you have have been milled to the excess, in addition to whatever else they have been through. . I seem to remember you saying that you have "8BA" heads. A good set should be easy to find. Getting the proper clearance over the piston head is one of the most rewarding things you can do with a flathead, in terms of both performance and personal satisfaction. Making sure you have adequate clearance over the valves is just another part of the process. I wouldn't put a flathead together without custom fitting the heads.

09-06-2023, 11:26 AM	#25
whatdoyouwant Senior Member Join Date: Jan 2022 Posts: 147	Re: 8BA engine It does seem like different heads are the right place to start. thanks for all al

09-06-2023, 02:27 PM	#26
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,320	Re: 8BA engine Sponsored Links (Register now to hide all advertisements) I think the "thicker" gaskets are from a place called "Cometic" (or some such). Once you price them out, a set of good used heads will start to look pretty good.

09-06-2023, 03:51 PM	#27
Ggmac Senior Member Join Date: Jul 2016 Location: Lake worth Florida Posts: 1,104	Re: 8BA engine Where do you live ?

09-07-2023, 05:26 PM	#29
whatdoyouwant Senior Member Join Date: Jan 2022 Posts: 147	Re: 8BA engine I don't know if 8BA heads are the same as 8CM heads, but if they are my heads must have been milled about .050". I will begin to look for different heads.