05-23-2014, 08:08 PM | #1 |
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Head Flatness
I have a police head for my car (has a B cast in the top) and I measured the flatness on the bottom of the head with a straight edge and it is 5 thousands of an inch off in the center. Is this too much or should this be ok?
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05-23-2014, 08:18 PM | #2 |
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Re: Head Flatness
I'm just a shade tree mechanic, but I'd use it as is. Heads are more flexible than we think, and the gasket is going to absorb the difference. Torque in the proper sequence, and retorque a couple more times after driving it a bit. There's your free advice, for what it's worth.
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05-23-2014, 09:08 PM | #3 |
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Re: Head Flatness
Why waste time and gaskets for a 40$ resurface job? I could do it tomorrow if you were close.
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05-23-2014, 09:18 PM | #4 |
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Re: Head Flatness
nah leave it as is then just shave the head and change the gasket next month when it won't seal.
It is hard enough to seal a Model A head as it is.........
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05-23-2014, 09:31 PM | #5 |
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Re: Head Flatness
It's hard to understand why back in the day of nice thick copper headgaskets I don't recall any blown head gaskets on Model "A"s, and we used to pry them off with large screwdrivers and small crowbars, taking a file to both head and block after a difficult removal.... and we didn't even own a torque wrench - just kept them snugged tight. Are gaskets that different today ????
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05-23-2014, 11:34 PM | #6 |
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Re: Head Flatness
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05-23-2014, 11:41 PM | #7 |
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Re: Head Flatness
When I worked on heads at the shop we set the limit at .005" for the length of the head and .003" for the width of the head. I wouldn't surface a head for being .002" out.
Model A's have quite a spread between head studs, so using a head out by .005" would be taking a chance. |
05-24-2014, 12:14 AM | #8 |
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Re: Head Flatness
I surface flat heads and manifolds on my table saw with some stick on sanding discs. I live on an island with no machine shop, but also I am cheap and enjoy doing things myself. I blew my head gasket using a head with 'speed head' cast on it. I surfaced a standard head and am using that with a graph-tite head gasket. No seeps.
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05-24-2014, 01:35 AM | #9 |
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Re: Head Flatness
.002 is my guide as well I have my own van Norman broach and head / block resurfacing equipment . Piece of cake and like James said, why not for $40 and know its going to be good. I wouldn't be doing good work for folks if I didn't do it
I would find a machine shop and get it right. Yes, cast iron is flexible in torquing heads , but then why take a chance on sealing and issues when head gaskets cost are $25 plus Larry s |
05-24-2014, 06:19 AM | #10 | |
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Re: Head Flatness
Quote:
I,m with Tom on this one. Depends who and how they are milling the head. It might come out more than .005. It all depends on the cutter, and how they are holding the part down. It is not as easy as it sounds. |
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05-24-2014, 11:56 AM | #11 | |
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Re: Head Flatness
Quote:
the area between cylinders 1,2 and 3,4 is narrower on the newer gasket. I think that may be one problem. http://www.fordgarage.com/pages/felproAheadgasket.htm Bob Last edited by Bob C; 05-24-2014 at 01:22 PM. |
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05-24-2014, 11:54 PM | #12 |
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Location: New hope Minnesota
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Re: Head Flatness
Iff it is off by .005 I would resurface.
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05-25-2014, 12:04 AM | #13 | |
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Re: Head Flatness
Quote:
Next was copper or steel sandwich with asbestos filling which has very high temp resistance and also self sealing when in contact with fluids Banned today |
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