New head with defect
Thread Starter
XX
Joined: Jul 2009
Posts: 859
Likes: 40
From: Louisiana
St. Jude Donor '12
New head with defect
Just got a new pair of heads and one has a punch mark or machining defect on the exhaust port where the gasket seals. I am concerned it could be a problem for exhaust leak so I added a pics to see who would exchange it or not worry about it.
Pro
Joined: Aug 2010
Posts: 593
Likes: 9
From: San Antonio Texas
It is hard to tell about what this is exactly but from my days in castings and machining it looks to me like a Brinell test (hardness) indentation. It is not a casting defect as it is shiny on the inside, and I don't think it is a machining defect either. I can not for the life of me understand why anyone would take a hardness reading at that place on the surface and I have no idea if that would be an issue on sealing a gasket. I would think it would but I am not an expert on this. A Brinell tester takes a full ball radius and under a specific load makes an indentation on the surface of materials like aluminum. You then measure the depth of the indentation to get a relative hardness of the material. In steel you would use a different scale called Rockwell C. Good Luck.
Thread Starter
XX
Joined: Jul 2009
Posts: 859
Likes: 40
From: Louisiana
St. Jude Donor '12
I can not complain about Pace the vender, it's up to me as to what I want. I didn't want to do the RMA unless it was justified. Here is there response:
Hi Kerry,
I've seen marks like that in a lot of the LS heads, I think they have to do with the fixture that held it while it was machined. I looked at an LS3 exhaust gasket and there is a good 5/16" worth of sealing area around each port so I don't see any problems with a leak.
If you feel you want to exchange it, let me know and I'll get you an RMA number.
Mark
Hi Kerry,
I've seen marks like that in a lot of the LS heads, I think they have to do with the fixture that held it while it was machined. I looked at an LS3 exhaust gasket and there is a good 5/16" worth of sealing area around each port so I don't see any problems with a leak.
If you feel you want to exchange it, let me know and I'll get you an RMA number.
Mark
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
Hold the gasket up to the head. If the detent falls within the inner first contact area of the gasket you should be fine. If it falls on the contact area of the gasket it might be an issue, but I doubt it. Your car and engine, do what you feel is best.
