Re: Unleaded Petrol

[MMoore8425@domain.elided]

I don't now how many people have experienced valve gear failure due to
unleaded fuel. I have, and it might be helpful to explain the circumstances,
albeit on a different car.
I had the engine of my 1962 Chrysler 300H rebuilt by Lee Hamilton Racing
Engines in 1984. No hardened seats, no special valves or guides. This is a 380
hp 413 dual carb engine. I drove the car to California, burning leaded hi
octane until it became unavailable in 1986. I continued, adding octane booster
at every fill up. In 1988, with 19,000 miles on the odometer since rebuild I
drove the car to Victoria BC from LA in a very hot July. I drove up the
Sierras at high speed at 7000 feet. I drove the car very fast. At one point
checking full throttle upshift  (110 mph or so) several times. I was driving
up very steep grades. I was driving the car in heat up to 118F. In Victoria,
the engine was getting noisy. By the time I got to Portland,Oregon, on the
return, it was very loud. I did a valve job in Portland, and put hardened
seats in. The valves had become recessed and two guides had worn through the
wall and were going into the head. I had always used additives or leaded
gasoline up to that time. 

I do not think I would have had a problem except for the long, long, uphill
hot drives.
By comparison, I've driven my Stag in similar circumstances without any thing
other than stock Stag seats, valves, and guides. I had to remove the heads
after 20,000 miles to repair the "cold welding", AKA glue,  the "Stag
Specialist" had put in to cure corrosion damage. The valves, guides, and seats
were great.

Has anyone had a valve recession problem with a Stag running on unleaded? I am
not worried about mine. I do NOT use a lead additive.

Mike Moore 
MkI