Darrell,
I think the cylinder wall failure on the Ardun/Merc was the result of
hydraulicking the thing a couple of times during engine starting.
When I finished the fuel system on the modified roadster I installed a
"tip" valve in the fuel tank vent line to comply with SCTA rules. I didn't
realize it at the time, but the "tip" valve really works well and won't allow
ANYTHING out of the tank.
After filling the tank and home and driving over 4200' Tejon Pass the
pressure in the tank was greater than the outside air pressure, causing the
fuel to flow through the pump, barrel valve, and nozzles, into the cylinders.
The hydraulic situation cleared itself out at the Lakes after a couple of
hits from the starter, but when we went to the World Finals over a couple of
7000' passes and through 80 deg weather the cylinders REALLY got filled.
I suspect that the cylinder was wounded from those 2 incidents and
finally gave up on the 4th pass. I've run 12.6 pistons on 80% in the "wet"
dragster engine for years with no cylinder problem.
I've had to change my operating procedure so as to leave the fuel valve
in the "off-bypass" position at all times other than running the engine.
I may try to sleeve the block, but I probably will keep it as a "spare".
Ardun Doug King
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