E-type valve seat job
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E-type valve seat job
I just bought 1973 Series 3 V-12 E-type.
It's in great condition but it had an overheat event and the previous owner stripped it down to investigate the damage.
Each head has one exhaust valve seat that has dropped, interfering with the piston and causing minor piston damage. The crank and pistons all move OK.
How should I go about removing the old valve seats?
Machine them out?
Heat the head? (warping?)
Grind them out?
Drill small holes in the seat periphery to collapse them?
What's the shape of the seat? Square corner?
Any insider tips for this job?
I have a complete workshop and most machine tools.
Thanks for any tips?
Harvey4
It's in great condition but it had an overheat event and the previous owner stripped it down to investigate the damage.
Each head has one exhaust valve seat that has dropped, interfering with the piston and causing minor piston damage. The crank and pistons all move OK.
How should I go about removing the old valve seats?
Machine them out?
Heat the head? (warping?)
Grind them out?
Drill small holes in the seat periphery to collapse them?
What's the shape of the seat? Square corner?
Any insider tips for this job?
I have a complete workshop and most machine tools.
Thanks for any tips?
Harvey4
Veteran Member
Joined: Dec 2009
Posts: 9,547
Likes: 2,545
From: Crewe, England
These are hardened valve seats, so much care is necessary. It is the kind of job an engine rebuild shop would normally do. Difficulty is likely to be in inserting the new seats, not taking out the old ones.
As I recall, they are normally machined out, and the head heated before inserting the new ones on an interference fit basis.
Both the V12 and XK engines should have the hardened valve seats from about 1967-1968 onwards so will handle unleaded fuel already.
As I recall, they are normally machined out, and the head heated before inserting the new ones on an interference fit basis.
Both the V12 and XK engines should have the hardened valve seats from about 1967-1968 onwards so will handle unleaded fuel already.
Junior Member
Joined: Nov 2011
Posts: 7
Likes: 0
From: albuquerque NM
seats
If you are considering doing this seat job yourself, you are playing with fire ! This should normally be done by a qualified automotive machine shop familiar with aluminum heads. The 12's were bad about overheating and dropping the seats, causing untold damage, so there could be others that are nearly ready to drop. Let an expert that you can trust handle this one, you might get in over your head very quickly ! (no disrespect intended) This is all done with interference fitting, and unless you are familiar with it all, you may just build yourself a bomb ! Check the condition of the pistons and cylinder walls for galling or other damage as best you can as well. If the head warps badly enough it can also affect the align bore of the cams. Good luck
Junior Member
Joined: Apr 2012
Posts: 4
Likes: 0
From: PA
Unleaded fuel
Just to confirm; I can use straight unleaded fuel in my '70 XKE without issue ?
Junior Member
Joined: Oct 2011
Posts: 14
Likes: 0
From: Mojave Desert
Is this a feeling or is there some documentation that backs this up?
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