Racing Fuel Series II 88??

[homchz]

Girlfriend's Rig, she let a few friends work on it. One is a back woods mechanic fix all type and he went down and put a higher octane racing fuel in the rig saying it would help "Clean Her Out". Also that these engines were designed for leaded gas and the leaded racing fuel would be good...(It has sat for a year or more)

How it runs right now, I question all of this. I always thought racing fuel while it can contain lead for a higher octane rating and more "power" is designed for engines that need it. Right now the truck is idling horribly, decent amount of black exhaust on idle and smells awful to boot. Used to turn over with just the choke out and a turn of the key and now takes pedal pumps and many feathering attempts when it does start...

Should we just be running normal octane gas or does her friend have a point about the racing fuel. Would hate to see this do any damage to the engine. Which was running really good for it's age when we parked it for the winter.

Thanks,

[SafeAirOne]

You have to time the ignition for the octane rating of the fuel you are burning.

[lumpydog]

These trucks were designed to run on third world fuel.... albeit, leaded. But generally speaking, a lower (less expensive) octane rating was expected. Then again, no ethanol or other additive crap was expected either.

With today's fuel (no lead) hardened valves are a good idea. As SafeAir points out - timing needs to be adjusted to support different octanes - as higher octane burns slower. Higher octane needs more advance on timing. Lower octane... less advance.

My advice - go with 87ish octane and set the engine's timing to work with it. If possible - avoid ethanol... harder to do these days.

[o2batsea]

The myth is that all engines built in the time of leaded fuel REQUIRE leaded fuel to run properly. This is complete and utter hogwash. What lead in fuel does for the engine is to add a "cushioning" effect to the closing exhaust valve, theoretically prolonging engine life. This is mostly for high performance engines running at high RPMs (8K +). Unless you operate your Rover with it WFO for days and days, you are not going to have to worry about the lead thing.