compression vs octane

blaster800 · 06-16-2006, 04:16 PM

hi ! im running 210 psi in a 701 eng bored to 83.5 mm, ported ,etc,etc, i need to know APPROXIMATLY ''10 20 30 40 50% '' how much 110 octane fuel i should mix with 93 octane pump fuel to safely ward off pre ig ????? the reason for the 110 octane is that they sell it in bulk down the road . also i dont want to change heads yet due to the fact ill probly sell this ski at the end of the season when my 800 is done , THANKS !

Ocean Pro · 06-16-2006, 04:52 PM

Quote:

Originally Posted by blaster800

hi ! im running 210 psi in a 701 eng bored to 83.5 mm, ported ,etc,etc, i need to know APPROXIMATLY ''10 20 30 40 50% '' how much 110 octane fuel i should mix with 93 octane pump fuel to safely ward off pre ig ????? the reason for the 110 octane is that they sell it in bulk down the road . also i dont want to change heads yet due to the fact ill probly sell this ski at the end of the season when my 800 is done , THANKS !

110 octane correlates to about a 14:1 compression ratio figure on my octane chart. Calc your ratio and I will check it on my chart I don't know the answer when you dilute it with regular pump gas. Maybe Bill O'neal has some ideas

blaster800 · 06-16-2006, 06:08 PM

thanks for the reply . i dont know the comp ratio so ill ask Bill i guess ! thanks: frank

jetskimechanic · 06-18-2006, 10:46 AM

With that compression you better run the 110 race fuel...