Are hardened valve seats necessary?

[Jac Mac]

Originally Posted by Excaliber

I totally understand the delima of what CAN be done vs what really NEEDS to be done. Here on Club Cobra the advice almost always leans toward what CAN be done, spare no expense etc. There is a place for that, but not all of us are on a limited budget.

Heres why I would NOT worry about hardened valve seats:
When unleaded gas first came on the scene virtually a 100% of the industry recommended hardened seats, solid advice, but not needed for everyone. Turns out the valve seats are at risk when your driving a LOT of miles in a SINGLE journey. Keeping the temps up over a period of time is what kills the seats. Shorter trips, lower mileage are not so much of a problem. I would think that also applies to limited track use, run some laps, pit, run some more. Running it HARD and LONG? Use a lead additive in the tank for such conditions.

767 Jockey,

There is a lot of merit in what Ernie states above. Quite frankly if I were in your position I would not use them if the car was not going to be a daily-longer trip driver. Fit the stainless exh valves and single groove retainers( DO NOT use the std 3 groove type that promote/allow valve rotation), Choose a cam profile that use's a 'tight lash' setting to ease the seating , this helps a bit and get a few gallons of av gas to put about 10% mix in for longer trips. On shorter runs there seems to be enough lube from cold starts & stem oil to prevent rapid wear.Ensure that you use good valve springs/retainers to eliminate any valve rotation & therefore the tendency for the valve to try and weld itself to the seat when closing which is the real cause of the seat erosion. I have been in the auto repair business for the last 40 years thru all this BS and saw seat erosion big time in jet boats used in tourism in Queenstown NZ. These run all day @ around 4000 rpm. While the decreasing lead values were part of the problem, the biggest single factor was getting the correct valve spring package and cam profile to eliminate any spring surge etc. We could kill a set of standard exh valve seats in around 450 hrs if the wrong combo was fitted.
I know this flys in the face of what some PC folk will tell you, but when Im paying & or doing the maintainance, what works for me is what gets done!

Should have mentioned the boats were powered by Clevelands!

Jac Mac