qeustion about octane boosters

[RfirstVette]

do they work and do i need one ? octane around here only gets up around 91 . My car has a 350 .30 over , aluminum heads ( 64cc) pro-flo fuelinjection.
Thanks,
Gary

 

[Jack]

You didn't state your compression ratio or type pistons you're using. If the block has NOT been decked ... stock pistons probably dished. With 64cc chambers and with dished the CR probably about 9:1 ... or with flat top pistons CR probably about 9.5:1.
Either 9:1 or 9.5:1 should be no problem with 91 octane and Al heads.

Virtually all octane boosters have little real effect. Do a search here of CAC forums ... there's a lotta great info here ... much of it already been covered many times over.
JACK:gap

 

[SMKN97GP]

even if you do need booster, the best octance booster you can get at a regular parts store will only bring the gas from 91- 91.5 or some sh*t like that.

 

[Vettehead Mikey]

The biggest 'boost' most of these products give is to the ego of the owner. I suppose it makes them feel more stud-like and testosterone charged to think that their car is one of the few that needs and benefits from an octane booster.

It is true that some of the products on the market do little or nothing to raise octane levels, but there are reportedly some that can demonstrate actual increases in the ratings.

Fact is that 99.9% of Corvettes on the street today don't need it and don't benefit from using it.

Contrary to urban legends and myths, high octane gas does not produce more energy or power, in fact does quite the opposite.

Bring on the flames!

 

[RfirstVette]

I really don't know thr C.R. , the guy I bought it from said probably 10:1 but i don't think he really knew

The reason I asked was sometimes when I stomp on the accelerator it kind of pings/rattles. So it could just be timing or something or the fact it has only been driven 500 miles in the past 2 years by the guy I bought it from. Gas probably isn't the best after that much time either I guess.
gary

 

[Jack]

The reason I asked was sometimes when I stomp on the accelerator it kind of pings/rattles. So it could just be timing or something or the fact it has only been driven 500 miles in the past 2 years by the guy I bought it from. Gas probably isn't the best after that much time either I guess.
gary

First ... siphon-out & dump or drive off that 2-year-old gas. If you're gonna run the old gas, do get some gas dryer from parts store. Or go to drug store and get two (2) one-pint bottles of 91% Isopropyl Alcohol and dump one bottle (16oz) in with old gas. When tank's nearly empty, dump the second bottle in as you fill up with fresh 91 octane gas. DO NOT bother with 70% alcohol ... 70% iso already has so much water attached to its molecules that there's no room for more ... get the 91% isopropyl. After you're into the second fillup with fresh 91 gas, then see if your spark rattle is still a problem ... if so, then look to timing. Make sure the distributor's mechanical (centrifugal) and vacuum advance systems are functioning normally and there's no vacuum leaks. If all that checks OK ... then back off the timing about 2 degrees (ie from 36 go to 34). Only back off the timing after you've checked & verified all advance systems check AOK.
JACK:gap

 

[RfirstVette]

Thanks Jack.

 

[jeffyc]

me when my z28 was going and had a compression ratio of 10.8 (aprox) to 1
i would per 20 gallons of fuel put in 1/2 a liter (some one will have to figure that out in pints, but its about a 1/8 of a gallon of kerosene) in my tank but i also put in 91 octane
i dont know what that brought the octane up to but my 412 didnt detonate
and it would on just 91 octane

 

[MaineShark]

Now here's a thought, since Jack brought up isopropyl alcohol (side note: some stores have higher than 91% - higher is better as gas dryer, if you can get it)...

Isopropyl has a higher octane rating than gasoline. I'm not sure how much, but if someone does, I sure know how to figure out if something nice and cheap like that could be used as an octane booster, on the cars that actually need it.

Joe