FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: Jason R on August 05, 2016, 11:41:42 AM
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Hello guys, I'm looking for some help on figuring out proper milling of a set of heads. I have a pair of C6ae-R's that are date coded a year or so apart and of unknown history. The newer head 6C18 took a .005" surface cut to clean up and have an average chamber CC of 69. The older head 5L19 looks like it's going to need about .030" to .035" to get its average CC's to match (around 72 avg now). So once I cut this one that much what should I do to the intake face? Also should I expect any issues in intake port alignment or block fit that a basic port match at assembly won't fix? I don't have a block ready for them now to really check things out. Once again thanks in advance for all the great feedback and experience we get off this forum.
Jason
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More info I forgot to mention I have already cut about .015" of the estimated .030" to get to my 72 cc average on the older head. It's not consistent but I seem to get around 1cc for every .005 I cut off.
Thanks
Jason
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I'd get the heads and block done first, then see what you got with the intake before you start making any mods. If its a rare or expensive intake I would try and make the adjustments with different gaskets and such first. I'm not a fan of cutting a intake that's not easy replaced. If its just a standard or popular shelf manifold then maybe not much worry in cutting on it. Still though, I say mock up with the cut block and heads and head gaskets you plan on using then fit the intake and make adjustments to it.
JMO.
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I can't answer all your questions, but I can give you a little to think about - all FE wedge heads have a cast in "thumbprint" ( pictures below ). The "Thumbprint" actually looks like a thumbprint on the deck surface of the head. The thumbprint can be useful to gauge how much a head has already been milled. There is actually a Ford spec on how deep the thumbprint is on a new head ( I don't know it off hand ), but for the purposes here you'll get the idea. Look at the picture of this first head that has only been slightly milled.
(http://i1235.photobucket.com/albums/ff437/red0wl/FE%20head%20thumbprint%20001%20rs.jpg) (http://s1235.photobucket.com/user/red0wl/media/FE%20head%20thumbprint%20001%20rs.jpg.html)
Now look at this picture of a different head that has been milled much more, to the point almost all the thumbprint is gone.
(http://i1235.photobucket.com/albums/ff437/red0wl/FE%20head%20thumbprint%20003%20rs.jpg) (http://s1235.photobucket.com/user/red0wl/media/FE%20head%20thumbprint%20003%20rs.jpg.html)
There are also Ford FE head blueprint specs where you can reference things like measurement from the deck to certain bolt holes, etc., but my point is - first you should look at the thumbprint of both heads. I'm going to guess that the one head with less cc's was already milled before you got it. I think along with looking to even up the chamber cc's you will also want to look at how close to the same both deck surfaces are milled so as not to have alignment issues . You're on the right track.
I agree with what fekbmax said, now days I wouldn't advise taking off any more material than needed on rare FE parts like heads and intakes. The C6AE-R heads aren't extremely valuable, and we don't know what intake you have, but best to have a plan in place before doing too much cutting. Since you don't have a block in hand right now you'll want to consider that whatever original FE block you come up with ( if that's the plan ) may or may not already have been milled too sometime in it's past and that's something you'll have to take into account.
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Thanks for the info and those pictures. I won't mess with my intake manifold till my block is ready and I can fit it up. I went ahead and cut the older head .015" more for a total of .030" and now both heads chamber CC's average around 69. The thumbnails mentioned look to be between those two pictured, approx .050" on the newer head and .025" on the older one. Now I'm wondering is there a set amount I need to cut the intake face of the older head just because I cut .030" off its deck surface?
Thanks again
Jason
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Most of the experts here would say that you should cut as much off the intake face of the head as you do the head gasket surface. That will minimize changes to the intake manifold fitment. (Of course you may want to check intake fitment first and cut less/ more to get the intake manifold sitting correctly.)
This will make it a lot easier in the future to swap a new intake manifold over, plus you won't be hacking up a potentially rare intake manifold.
JMO - Bill
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I can't answer all your questions, but I can give you a little to think about - all FE wedge heads have a cast in "thumbprint" ( pictures below ). The "Thumbprint" actually looks like a thumbprint on the deck surface of the head. The thumbprint can be useful to gauge how much a head has already been milled. There is actually a Ford spec on how deep the thumbprint is on a new head ( I don't know it off hand ), but for the purposes here you'll get the idea. Look at the picture of this first head that has only been slightly milled.
There are also Ford FE head blueprint specs where you can reference things like measurement from the deck to certain bolt holes, etc., but my point is - first you should look at the thumbprint of both heads. I'm going to guess that the one head with less cc's was already milled before you got it. I think along with looking to even up the chamber cc's you will also want to look at how close to the same both deck surfaces are milled so as not to have alignment issues . You're on the right track.
I agree with what fekbmax said, now days I wouldn't advise taking off any more material than needed on rare FE parts like heads and intakes. The C6AE-R heads aren't extremely valuable, and we don't know what intake you have, but best to have a plan in place before doing too much cutting. Since you don't have a block in hand right now you'll want to consider that whatever original FE block you come up with ( if that's the plan ) may or may not already have been milled too sometime in it's past and that's something you'll have to take into account.
The spec for the thumb print is .13" and that is on a C5 drawing.
I find no problem with hacking and welding anything. lol