which fuel?
63 dart 360 2bbl 9-1 circle track engine. We are allowed race gas or pump gas, which should I use (I wouldn't think pinging would be a problem) tho I dont have quench. thank you for your time. & iirc there was something about race gas burning slower??. RR
Burn rate is pretty application specific.
Let’s say you are buying race gas for your deal and your maximum RPM will be 6500. The burn rate for the fuel you would need is going to be slower than some other engine that has a maximum RPM of 8500.
The burn rate for the fuel you would need would be slower than the higher RPM engine because the higher RPM engine will have less time to get the burn started and done than the lower RPM engine. If you used a slower burn rate fuel in a high RPM engine you’ll have to start the burn sooner to get it finished on time and not put a bunch of heat in the exhaust. Plus the timing required for the slower burn rate fuel would generate a ton of heat if you didn’t get it started early enough to finish the burn.
Burn rate isn’t octane related.
I would run that engine on pump gas but I would use premium fuel. Not because you need the octane (as RRR pointed out above it doesn’t really more than 87 octane) but because the low and mid grade fuels have a standard for blending that is…how can I say this…much more “loose” than premium pump fuels.
The rules for what can be blended into premium pump fuel are much tighter than the two lower grades. So the blend for those lower grade fuels have way more fillers and other junk in them.
You can usually see the difference between the lower grade pump fuels and premium pump fuel in the exhaust ports. Even if the tune up is spot on you can get gooey, nasty, dirty exhaust ports and that’s from all those fillers that don’t burn and don’t serve a purpose for making power.