[chevelle4542speed]

have 454 .30, forged pistons about 10.5 to 11 to 1 compression ratio.
i ran 83 octane and it was detenation. popping pingin. so i pump it out and put 93 oct no more problems. how much damage could of happen to the motor. seems to have a loss of power but it might be my ign or carb. how much damage did it do? or might of?

[69ChevelleAddict]

How many miles did you put on it with the 83 in there?

[Bumpstick]

Even 93 octane is on the border for 10.5-11.0 to 1 compression in a BBC... Also it depends on how long you ran it with 83...? Or did you mean 87 octane...? Depending on how long you ran it that way and how hard you pushed it will determine if any damage has been done... The less power feeling my be your conscience coming back to haunt you...

Might run a compression test to see if you beat anything up...

[docvette]

Doc here,

Pull the plugs, inspect them for White in color, with metal flecks on the ceramic element insulator. (need a magnifier glass or Digi cam with zoom)...

If you find any, this is indicative of piston metal being BLOWN off the dome of the pistons..

To determine damage is to remove and inspect the piston domes and chambers for deterioration..

Meanwhile invest in a case of BOOST and mix about a 110 octane mix per tank.

Doc

[xntrik]

Originally Posted by docvette

Doc here,


Meanwhile invest in a case of BOOST and mix about a 110 octane mix per tank.

Doc

What?

Just mix some AVGAS in it.

[DOUBLEDICK]

I run 11 to 1 pistons in my 427.Altitude is a factor as well. I live at 6500 feet elevation and I can get by on 91 pump gas with stock jetting and metering rods(.075x.047) on my edelbrock 750 with 4 degrees additional timing at home but if I go to Vegas I go 7 percent richer on my metering rods(.070x.o42) and use prestone 0 to 60 for a 101 octane and retard the timing to factory specification.I have 4.56 gears so the engine runs in higher rpm's and that helps with detonation issues.Depending on altitude and gear ratio's you may need a higher octane rating.I also use a vacume advance unilite distributer for drivability as this is my daily driver.

[chevelle4542speed]

well i have 3.73 gears, 2500 stall. this is not a daily driver, just friday and saturday nights , and ocassianal drag strip. since i ran the 93 it doenst seem to detanate. i check the spark splugs , pretty good shape, number 4 clyinder was a little white but not bad. i think the fuel mix is a little lean too. i have a predator carb ,needs to be rebuilt but cant find any info on it, i send a meesage to the predatorcarbgeru guy on here but nothing so far, do u know about any info on the carb, i google and yahoo search several times.

[chevelle4542speed]

Originally Posted by chevelle4542speed

well i have 3.73 gears, 2500 stall. this is not a daily driver, just friday and saturday nights , and ocassianal drag strip. since i ran the 93 it doenst seem to detanate. i check the spark splugs , pretty good shape, number 4 clyinder was a little white but not bad. i think the fuel mix is a little lean too. i have a predator carb ,needs to be rebuilt but cant find any info on it, i send a meesage to the predatorcarbgeru guy on here but nothing so far, do u know about any info on the carb, i google and yahoo search several times.

and the heads and pistons are polished and all cleaned up.

[glen242]

Originally Posted by chevelle4542speed

have 454 .30, forged pistons about 10.5 to 11 to 1 compression ratio.
i ran 83 octane and it was detenation. popping pingin. so i pump it out and put 93 oct no more problems. how much damage could of happen to the motor. seems to have a loss of power but it might be my ign or carb. how much damage did it do? or might of?

Where, in these United States, did you get 83 octane???