The Ford Barn

mrtexas · 05-25-2011, 05:24 PM

Macs says use a Model B gasket on a Model A block. I've lined up one of my used copper Felpro Model A head gaskets and why wouldn't that be a good one? Two holes at the top seemed to line up 90%, not 100%.

Anyone know for sure what is the best one for the Thomas head?

Looks like someone before me ran the head without a corrosion coupon. I had to get a couple places welded and the whole head planed. Now the only corrosion left is where there are holes in the head gasket. Got is for about 1/2 price of a new one.

nostalgicford · 05-25-2011, 05:55 PM

I run a Thomas Alumn head....had lots of problem with copper gaskets....you have three different metals...alumn...copper...and steel...and they react to heat different...I have not had any trouble blowing head gaskets since I went to a Felpro but it was not copper...

PC/SR · 05-25-2011, 08:31 PM

I use a Best composition gasket on a Weiand alunimum head, works fine, stock bore. I have seen that the B gasket is a touch wider in the part in the quench area between 1-2 and 3-4, and therefore a bit stronger, but maybe its different manufacturers rather than design. I would be kinda leery of using the copper gasket on aluminum head because of electrolasis (sp) of dissimilar metals. However, I did call a tech guy at Best about using a copper tack spray and he said that would be OK, so I dont know how much copper you need to cause that problem. Use the sacrificial zincs the suppliers sell, whatever gasket you use.

Jim Brierley · 05-26-2011, 10:47 AM

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A 'B' gasket MIGHT fit the combustion chamber better, it also MIGHT hang out into the chamber, so use whichever fits better. I would probably use an A gasket and smooth the sharp edges. Don't worry about only getting 90% of the water passages, that is more than enough.

05-25-2011, 05:24 PM	#1
mrtexas Senior Member Join Date: May 2010 Location: Sugar Land, TX Posts: 4,420	Thomas aluminum head gasket Macs says use a Model B gasket on a Model A block. I've lined up one of my used copper Felpro Model A head gaskets and why wouldn't that be a good one? Two holes at the top seemed to line up 90%, not 100%. Anyone know for sure what is the best one for the Thomas head? Looks like someone before me ran the head without a corrosion coupon. I had to get a couple places welded and the whole head planed. Now the only corrosion left is where there are holes in the head gasket. Got is for about 1/2 price of a new one.

05-25-2011, 05:55 PM	#2
nostalgicford Senior Member Join Date: May 2010 Location: Claremore, Okla. Posts: 259	Re: Thomas aluminum head gasket I run a Thomas Alumn head....had lots of problem with copper gaskets....you have three different metals...alumn...copper...and steel...and they react to heat different...I have not had any trouble blowing head gaskets since I went to a Felpro but it was not copper...

05-25-2011, 08:31 PM	#3
PC/SR Senior Member Join Date: May 2010 Location: Santa Rosa, CA Posts: 1,285	Re: Thomas aluminum head gasket I use a Best composition gasket on a Weiand alunimum head, works fine, stock bore. I have seen that the B gasket is a touch wider in the part in the quench area between 1-2 and 3-4, and therefore a bit stronger, but maybe its different manufacturers rather than design. I would be kinda leery of using the copper gasket on aluminum head because of electrolasis (sp) of dissimilar metals. However, I did call a tech guy at Best about using a copper tack spray and he said that would be OK, so I dont know how much copper you need to cause that problem. Use the sacrificial zincs the suppliers sell, whatever gasket you use.

05-26-2011, 10:47 AM	#4
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,251	Re: Thomas aluminum head gasket Sponsored Links (Register now to hide all advertisements) A 'B' gasket MIGHT fit the combustion chamber better, it also MIGHT hang out into the chamber, so use whichever fits better. I would probably use an A gasket and smooth the sharp edges. Don't worry about only getting 90% of the water passages, that is more than enough.