I have a 1971 XKE V12 2+2 and just had the engine rebuilt. I drove it just under 500 miles and a valve let go. Needless to say, I’m very disappointed. The engine rebuilder said that now I need to replace the cylinder heads before he can fix and rebuild the engine (AGAIN??). During the first overhaul (He said) they were over milled or something that he failed to inform me of or something…I just don’t really understand? That being said, I need a matched set of “Complete” V12 heads both Right and Left. Hopefully good enough to use with little or no milling required on the matting surface. Let me know what you may have available. Call or Text 1-408-210-4736. I need advice and any assistance is appreciated.
Step 1: You need a new mechanic.
YES! You definitely need a new mechanic. You can’t over mill early heads, you will hit the valve seats.
Apparently your engine rebuilder doesn’t warranty his work? 500 miles and and a dropped valve?
You only need one head as with a Flat Head milling them doesn’t change the CR.
As matter of interest why did the engine require a rebuild? I’ve known these engines to do more than 500K without a rebuild, they are not Ferrari’s or some “lesser” exotic.
OK i chopped /milled/planed (what ever its called) .050 thousandths off my Prehe heads,like 2MM.
and that was 26yrs ago, still runnin fine and was out yesterday showin off and brought it up to 6500RPM!
just be sure to check timing chain and tensioner for proper tracking clearances!
I agree, all the signs are there for you to seek another mechanic.
If you fail to find Pre-HE heads (or complete engine), you could consider buying an HE engine (should be “cheap”) and rebuilding the HE engine onto your original block. I’ve done this.
This way you end up with a matching numbers engine, running high compression HE technology. I was amazed at how much more torque the HE engine produces over the low compression pre-HE. Of course the HE does not really rev beyond 5500rpm but by then the job is done anyway.
The most obvious way of knowing what heads your car will have, is looking at the way the plugs are positioned. IOW, its very subtle.
WARNING: If you do this, you WILL be frustrated by the lack of overdrive 5th gear.