May have fixed one perceived problem but did the cams turn freely once the head was bolted down, that's the question.

 

Yes the engine fired first try.....

 

That is good news but I would be a little concerned about cam bearing wear. Hope for the best.

 

Are there individual bearings at each cam shaft cap?
And (this is just for my learning), why would they wear in this circumstance?

 

why would you worry about the cam bearings as they were not affected by removing the heads?

 

Gere's your post and you did ask how much the heads were warped!!! Out of interest how much were the heads warped?

 

Picture if you will to straight rods next to each other. If one gets bent / warped it will put pressure on the other. as in they are no longer parallel. Same for the head, if it warped, say .030 or so, it effected its straightness, resurfacing the head, flattens the surface /face of the head. but does not address the straightness of the head itself.

Jack

 

Thank you Jack... Well explained and I get it now!
cool

I won't post here going forward (unless I have a question about the OP and folks responses). This thread seems to be getting off from helping with the dilemma this dude is facing.

 

No separate bearing shells, the aluminum acts as the bearing material.

 

If the head is bent longitudinally the bore through the cam bearings is no longer straight. Skimming the head surface leaves the cam bearings out of alignment permanently. The head should really be straightened in an oven rather than skimmed. And aluminum heads will pull down straight a lot easier than cast iron. I just repaired the head gaskets on an overheated XFR 5.0 SC. One head was 7 thou bent in the center. Jaguar specify a max tolerance of 0.2mm which is around 8 thou. It pulled down fine (so far 1,000 miles).

 

you should be able to check the bearing carriers with a straight edge to see if it was affected too, can't you?

 

In Theory, yes.

Jack

 

and in reality

 

I think this is the reason that if a V12 head is machined, BOTH the top and the bottom surfaces must be done to ensure they are parallel. As the cam carrier is a separate casting, and assuming it is straight, the cam bearing alignment problem should not occur. That is my understanding, but I am ready to be corrected.
Of course on a head with integral cam bearings, assuming the head is warped longitudinally, this top and bottom machining option is not available, and your point is valid.

 

​​​​​​I doubt if you would get meaningful results with just a straight edge.

 

That sounds reasonable. But the engine above (BigAl Bre) is an XK8 with integral bearings. We kind of hijacked the post but I don't think the OP came back anyway.