what octane fuel should i be mixing with my oil at 30 to 1 if you havent read any of my other ?s i have taken the oil injection off,no lid on airbox,bored .080 over and i am going to be jetting it or bigger carb and jetting soon along with + 4 timing and full pipes.
gas?
- Thread starter lowlow28
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Blaner
Your Friendly South African Ambassador
agreed. However, i believe there is no advantage at all in using high octane fuel, ie: higher than pump (avgas etc) because all that a higher octane number is is the fuels point of combustion. A higher rated fuel will combust at higher temps that say 93, so unless you running extreme compression which caused higher temps and your motor is detonating etc, normal pump gas will do perfectly well.
i agree, our pumps here in the U.S. 9 times out of 10 have 87, 89, and 93. every now and then you can find a sunoco with 94 but not around me lol
Blaner
Your Friendly South African Ambassador
Premium at least. The best we have here is 92, but that is good enough. If you can though, try to get non-alcohol blend. The alcohol is hard on seals and makes the octane kinda iffy. I get mine direct from the local oil/gas distributor for on a couple cents more (he sells race gas too).
I have heard octain boosters are bad. i would just run that 91 and you'll be fine
Blaner
Your Friendly South African Ambassador
+1 to that, and here's why.
Octane is a combustion retardant. It makes the fuel more resistant to self-ignition under pressure. A motor's recommended octane is based on a number of things, but cylinder compression and timing are the two biggest factors.
Maximum power is developed running the lowest octane fuel possible that doesn't detonate. In a perfectly ideal case, the spark would light the fuel just before the mix would detonate from pressure/heat, meaning the mixture is at it's maximum possible volatility.
If you run high octane in a motor that only calls for 87, the mixture won't be as volatile as if you used 87, since the octane effectively raises the amount of pressure required. You LOSE power running high octane in a motor designed for regular. Since the fuel is less volatile, it burns slightly cooler, which some people think is a good thing and will make the motor last longer. Also wrong. If the motor burns cooler than designed, deposits and carbon that would normally be burnt off will build up on your valves(or here ports) and head.
Even people running milled heads or such may not need premium. If it doesn't detonate/ping with regular, you're golden. The Yamaha Vmax motorcycle(which I'm quite familiar with) is a 1200cc V-4 four stroke that runs at 230psi of compression...quite a lot for a stock motor(and why it does 0-60 in 3 sec...lol). It only calls for 87, and there isn't a shred of evidence showing "premium" gas makes it run and better or faster. In fact a debate on this on another forum got so out of hand a shop owner decided to put it to bed once and for all and dyno test it. A 600 class sportbike, stock, calling for 87. 3 pulls on 87, 89, and 93 octane. It made maximum power on 87, and lost an average of 2hp on "premium".
Calling it "premium" fuel is the most clever bit of marketing ever. It's not higher quality, more refined, or purer than the regular. Running high octane in a motor designed for regular 87 is a complete waste of money.
All fuel is mandated to have ethanol now in equal levels, so you won't "avoid" e10 by buying premium either. The only hope for that is to get 100 octane avgas, but mine runs fine on e10. Just be sure to use the blue sta-bil if you let it sit for more than a couple weeks, and keep the tank as full as possible to prevent condensation.
Octane is a combustion retardant. It makes the fuel more resistant to self-ignition under pressure. A motor's recommended octane is based on a number of things, but cylinder compression and timing are the two biggest factors.
Maximum power is developed running the lowest octane fuel possible that doesn't detonate. In a perfectly ideal case, the spark would light the fuel just before the mix would detonate from pressure/heat, meaning the mixture is at it's maximum possible volatility.
If you run high octane in a motor that only calls for 87, the mixture won't be as volatile as if you used 87, since the octane effectively raises the amount of pressure required. You LOSE power running high octane in a motor designed for regular. Since the fuel is less volatile, it burns slightly cooler, which some people think is a good thing and will make the motor last longer. Also wrong. If the motor burns cooler than designed, deposits and carbon that would normally be burnt off will build up on your valves(or here ports) and head.
Even people running milled heads or such may not need premium. If it doesn't detonate/ping with regular, you're golden. The Yamaha Vmax motorcycle(which I'm quite familiar with) is a 1200cc V-4 four stroke that runs at 230psi of compression...quite a lot for a stock motor(and why it does 0-60 in 3 sec...lol). It only calls for 87, and there isn't a shred of evidence showing "premium" gas makes it run and better or faster. In fact a debate on this on another forum got so out of hand a shop owner decided to put it to bed once and for all and dyno test it. A 600 class sportbike, stock, calling for 87. 3 pulls on 87, 89, and 93 octane. It made maximum power on 87, and lost an average of 2hp on "premium".
Calling it "premium" fuel is the most clever bit of marketing ever. It's not higher quality, more refined, or purer than the regular. Running high octane in a motor designed for regular 87 is a complete waste of money.
All fuel is mandated to have ethanol now in equal levels, so you won't "avoid" e10 by buying premium either. The only hope for that is to get 100 octane avgas, but mine runs fine on e10. Just be sure to use the blue sta-bil if you let it sit for more than a couple weeks, and keep the tank as full as possible to prevent condensation.
