cylinder head surface pitting

scxr7

Registered User
http://www.yellowbullet.com/forum/showthread.php?t=248397

if you look very closely you will see small holes in the combustion chamber and all over the deck surface in general. looks like someone added a dash of pepper onto the heads. I don't think it will be much of an issue, but then again, These heads will be put through quite a bit of abuse in the future. I bought composite gaskets because I'm not sure if these heads will seal on an MLS gasket.

lemme know what you think. the guys on yellowbullet are pretty harsh lol.
 
Your heads?
The surface finish looks like junk too rough almost like there was a problem with the surfacer. I guess it could be the light. Does it feel smooth, or can you catch your nail on that?

The pits and such are typical with aluminum casting. Here is a picture of mine. Not a great picture, but you can see the difference in the surface finish, and the flash highlighted the casting flaws.

 
Ford cylinder head castings are very poor quality and very porous. You will find that the porosity looks worse within the area of the combustion chamber quench due to detonation opening up the pores even more, but they are present throughout the casting.

BTW, the surface looks like a typical carbide cutter. You are right, it will not work with MLS gaskets, but if the block wasn't surfaced then MLS won't work with the block either so composite gaskets will have to be used anyway even if the heads were perfect.

The heads Mike posted a picture of were done at our shop on a CBN cutter. What you see there is an RA 20 or better finish.
 
http://www.yellowbullet.com/forum/showthread.php?t=248397

if you look very closely you will see small holes in the combustion chamber and all over the deck surface in general. looks like someone added a dash of pepper onto the heads. I don't think it will be much of an issue, but then again, These heads will be put through quite a bit of abuse in the future. I bought composite gaskets because I'm not sure if these heads will seal on an MLS gasket.

lemme know what you think. the guys on yellowbullet are pretty harsh lol.

Are those the same heads that are supposed to flow 295 CFM @ .700 ? Doesn't look like any work was done in the combustion chamber to unshroud the intake valve, so I'm certian they don't flow anywhere near 295.

David
 
Are those the same heads that are supposed to flow 295 CFM @ .700 ? Doesn't look like any work was done in the combustion chamber to unshroud the intake valve, so I'm certian they don't flow anywhere near 295.

David

It's physically impossible to flow 295cfm through an SC head. It's probably not even possible to flow 295cfm past a 1.940 valve on any head regardless of port configuration. I'm sure they will work well though.
 
It's physically impossible to flow 295cfm through an SC head. It's probably not even possible to flow 295cfm past a 1.940 valve on any head regardless of port configuration. I'm sure they will work well though.

Well, depends on the amount of vacuum you apply to it, right? But at the standard vacuums (10 and 28 inches of water), it does sound impossible.
 
these heads are going on my "race motor". 20 over wiseco pistons, h beam rods etc.. the block has been decked and has a mirror finish on the decks.
 
these heads are going on my "race motor". 20 over wiseco pistons, h beam rods etc.. the block has been decked and has a mirror finish on the decks.

Then I highly recommend that you get the heads resurfaced to a likewise mirror finish and use MLS headgaskets. You are asking for trouble with that finish. A good shop can resurface those heads removing no more than .002-.003" which will not affect compression or deck integrity at all. You don't even have to disassemble the heads to have this done, just mask off the internal parts.

Make sure they use a CBN or similar cutter, NOT carbide. Ask to see some of their work if you have doubts. They should be very familiar with MLS headgaskets. All imports these days use MLS gaskets and require this type of finish also.

Trust me it will be worth the $50 or so it costs to have done.
 
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