Valve seat replacement

[Jakobs67gt500]

Good day Shelby'ers

GT500 #1739 sending greetings from Greece

I had an issue with a few valve seats, and got them repaired.
On one cylinder it was both valves which had issues.
The repair shop said I could face issues, as one valve is hot and the other cold, and it could create tension.
What is your point of view?

I may look for a spare head, just in case I have issues.
one head is made Dec 12/66 - the other Dec 13/66 and the block Dec 14/66

Many thanks in advance for your assistance

Best regards
Jakob

[pbf777]

The repair shop said I could face issues, as one valve is hot and the other cold, and it could create tension.

     This is often a problem even without the seat inserts!   

     Some of the advantage to the seat inserts (perhaps beyond the original purpose of a repair) is that they present a superior more resilient material replacing a sum of the surface casting material otherwise subjected to the greatest distortion load in the material movement due to temperature fluctuations and differentials in distance; which ultimately leads to fatigue stresses and failure.   

     Some of the disadvantage is that the removal of the parent casting material isn't going to make this casting any stronger (as most of these castings relevant were not designed or cast with the intention of such  ), and the the seat inserts are an interference fitment, pressed-in, thereby applying a spreading force, to a weakened area do to the material removal, in an area which already displays a tendency for failure!   

     But, properly executed, a good casting candidate, reasonable operational parameters, including realizing that most of these vintage vehicles aren't going to be subjected to such great usage, this may prove quite an acceptable repair; or perhaps as better terminology...........a 'salvage operation'.   

     Scott.

[shelbydoug]

All FE castings in that area under the valves and down into the ports are thin. Too thin.

There has been discussion in general about the "need" to install hardened seats in "vintage" US made iron engine head castings because of the elimination of lead from gasoline.

I'm not sure what exactly the lead has to do with anything but that "is" the discussion.


Seemingly at Ford, harder cast iron was used on all iron castings then say GM used. I don't know about the Mopars.

It may be the case at GM that cast iron heads can benefit from hardened seats but Fords simply do not need harder seats.


This is my opinion, so if you don't like it you can throw stones at me, I might even care, but ANYONE with specific knowledge of Ford FE cylinder heads would never install seats unless it was necessary AND only in the seat that needs it as a repair.

It is the FE series that has this specific issue. To my knowledge none of the other Ford V8's have this problem.

Believe what you want to but it just is not a good idea to install valve seats in a Ford FE head. It's risky at best.

[TA Coupe]

Lead acts as a cushion for the valves so they don't pound the seats into submission.  There are many lead substitutes you can buy so this doesn't happen. I have been using Redline lead substitute for 20 years or so. The OP said he had problems with the seats and that's why he had new ones put in, hopefully the shop knew what they were doing.

       Roy

[Jakobs67gt500]

Many thanks for your replies - very useful.
I have only replaced the valve seats which were "burned"