Reply To: Cracked valve seats

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Hi,

Here’s an example of the stainless exhaust valves giving trouble. I had this happen a couple times with my ’29 after returning from driving to an Annual Meet. If I did it right there should be a photo link below where you can see my first four cylinders. Number 2 shows that the exhaust valve has gotten very hot and has begun to erode along the edge. The valves had about 2000 miles on them at that time and were adjusted to .008 cold before the trip. I was also driving on a 4.58 rear gear but did not exceed 55 mph.

We theorized that the stainless valves were not transferring enough heat to the valve guide and were running too hot.

I did two things. I found an original set of exhaust valves and installed a 3.54 rear end. I did this before driving the car to the Texas meet from Chicago in 2000. We’ve had no trouble at all since.

With the 3.54 gear we have been able to cruise at 60 mph with no trouble. I think that both the stainless valves and the gear contributed to the trouble.

Hope this helps.

Bill

http://home.wowway.com/~billmorr/valves.002.jpg