oil pressure LOST, and then 24 hours later BACK

[Tom Wells]

Pete,

Since I wasn't there this is a guess: could the oil have foamed? Oil pressure goes to zero instantly if that happens.

Also, oil level can contribute to no oil pressure. Early on I was told it is better to add an extra quart to be safe on the track. The result was the opposite! An extra quart can cause some real problems. It turns out that running 1/2 quart low is much much better.

Also, are the drainback areas from the heads clear? At those engine speeds for sustained runs, an amazing amount of oil goes into the valve covers, which can stay a while if it can't drain easily back to the pan. Remember, it's being pumped up there under pressure, while gravity is all that's getting it back down.

Another suspect could be the gauge. Worth checking.

Might be extra cautious and cut the filter just to be sure nothing else is in there but oil...

At the very least I'd change the oil & filter.

Just guessing,

Tom