Quote:
Originally posted by Chevyguy
When I was towing my big block back from Mi with my mustang, I ran into pinging problems when I hit the uphill grades on the NY thruway. The Gas that I had filled with was 87 octane with 10% ethanol. Even though alcohol has more octane, it also has less btu/gal and burns at a lower air/fuel ratio. something like 6:1 vs 14:1 for gas, this is why alky carbs have giant jets. So.. adding 10% alcohol to gas is like watering it down, and can cause some leaning out. I had to fill up with some 94 Octane before I got to Mass since there is a high elevation pass.
Running more Ignition lead will feel like more compression since it builds cyl pressure. But.. it is different, the fuel is still burning longer, and more compression does probably give more power than low compression and more timing.
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Our Sprint car small block has 14:1 pistons, just under a .700" lift cam (I'm not allowed to share the exact specs
), is N/A, and has the magneto set to 32 degrees of advance. It runs on straight methanol. We would not be able to run it on 110 octane. Since methanol supports so much more compression, why wouldn't gasoline with 10% methanol be good for street performance? If it was 87 octane before the methanol, what would adding 10% methanol change the octane to?
Take care,
-Chris