Originally Posted by reflog
I took the vette (427/390) out for a drive yesterday. I had filled the car with Non-Oxygenated fuel for the drive. Stepped on the accelerator and got severe pinging. I know some of you are running the 468/502's so what fuel do you use in these engines? Is your compression less than the older BB's?
My engine is not built. I has the standard 10:1 compression ratio. A little hotter cam than factory but not outlandish. The heads are stock with hardened valve seats in them. The timing is at (or should be) 6 degrees. I am looking at possibly buying some VP and adding an couple of gallons to each tank full to get the damn thing to run without pinging. Any help is appreciated.
Last Monday I had a similar experience. I filled up with Exxon REAL GAS and the engine pings horrible.
This engine rarely
pings.. maybe 5 tanks in 15 years.
Some of the "real gas" is just pretty junky stuff even from a major supplier.
I think they sometimes dump a bunch of 87 into the 93 tanker.
No, octane booster won't help.
I had good luck in the mid 80's with the '70 350/350 11/1 compression by running Holley water injection with a 8" vacuum on-switch, but had just a little transition ping and I always though I needed a 10" switch.
Used a gallon of water every 120 miles but was easily driveable.
I have friends who have tried 1/2 AVgas. Sometimes it is enough to do the job, but it will run a tad richer as avgas is 10% lighter than car gas.= and the price is outrageous too..... $ 6 plus I hear.