I've got a 383 stroker 75, pretty much everything done to it besides forced induction. it's running at least 12:1 compression and it's tinging a little. i'm running 93 pump gas and i add a bottle of 104+ octane booster every tank. the timing has also been turned down(which helped alot) but it still does it when i get higher in the rpms. i would say around 3.5 to 4k rpms. my question is, is there a better way to boost up the octane level of the fuel? there is a shop here that sells 114 octane race gas. if i mixed a gallon with the 93 would it help more than that octane booster? it runs about $7 a gallon for the race gas so i don't wanna buy too much of that stuff.
thanks.

 

The race fuel would help out much more than the octane booster stuff.
What temp thermostat are you running?

 

not running a thermostat. it's just constant flow

 

Backing off on timing helps most at low RPM and there is always some RPM where it won't be enough back.

You will just have to ask around about where you can get race fuel. There is one station here in NC, only about four miles from me, that sells 103 octane race fule for $4,30 a gallon. Makes a difference. I don't know if adding octance booster to that helps further.

If it were me, I'd lower compression ratio a bit. 12:1 is just too radical for pump gas.

If you are desperate you could try some method to cool the intake charge: a small shot of nitrous, or methanol injection. But that is messy particularly on a carburated engine

 

Another way to cool it would be Co2. NX make a CO2 intercooler cooler that might be able to be rigged up for cooling other parts as well.

 

i'm gonna give the race fuel a shot and see if it helps. it's $7 a gallon here but it's like 114 or something. so it must just be aviation fuel. i have to get the linkage checked on my transmission first cause it got stuck in 4th the other day. it's a richmond transmission, the one that has like 3 sets of linkages. i'm thinking one isn't set right or is getting caught on something. it took some work on the chassis to get it to fit in the car so maybe it's just getting stuck on somehting. but anyway. thanks for the help guys. i'll try to race fuel and hopefully that'll help. i really don't wanna lower compression cause i love the power the car has. pretty much the fastest thing i've ever been in. we got duel edlebrock 4 barrel carbs, 750's i think. or 550s. somthing like that. roller rockers, roller cam. dart heads, hooker headers with the huge side pipes. i dunno what's all done with it so i'm not sure about alot of things. my dad built it and when he died i got the car. so i'm trying to figure this thing out. i'm use to rx7s and escorts haha. anyways thanks guys for the help