661 Oil Test 32:1 vs 40:1 vs 50:1 ?

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cuttinties

cuttinties

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Does racing fuel, like Sunoco 110, burn cleaner than regular gas in a premix?

I've tested 110 vs 93 in my ported 660 with a 212psi compression. The 110 tuned to 13,500 and the 93 tuned to 13900. The 110 cut times were greater than 10% faster.
I'd be willing to bet you have the only saw that sees gains from high octane. If it were so much faster please explain why it's not used in race saws?
 
Ron660

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I'd be willing to bet you have the only saw that sees gains from high octane. If it were so much faster please explain why it's not used in race saws?
I can only report my results. I repeated it several times with the same results. My limited tests showed you need at least 205 compression or more to see any benefits. I have a compression ratio chart that has been 100% accurate.
 
Ron660

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Did you remove the cylinder to calculate?[/QUOTE
Nothing complicated here...it's simple. Just do the following:
1). Put in your 93 premix and tune if necessary. Video several cuts.
2). Put in your 110 premix and retune if necessary. Video several cuts.
3). Check your times. There's your winner.
Both were mixed at 32:1
 
cuttinties

cuttinties

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The only way to calculate trapped compression ratio is by knowing the distance from the exhaust port roof to the top of the combustion chamber. You can't do that with the cylinder off. So your chart is wrong
 
bwalker
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Does racing fuel, like Sunoco 110, burn cleaner than regular gas in a premix?

I've tested 110 vs 93 in my ported 660 with a 212psi compression. The 110 tuned to 13,500 and the 93 tuned to 13900. The 110 cut times were greater than 10% faster.
Sunoco 110 has a distillation curve made for four strokes and would make two strokes run less than perfect, so I am supprised by your results.
 
Ron660

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The only way to calculate trapped compression ratio is by knowing the distance from the exhaust port roof to the top of the combustion chamber. You can't do that with the cylinder off. So your chart is wrong
Every saw I've texted against the chart has been 100% accurate. I had doubts also until I ran tests.
 
Ron660

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Sunoco 110 has a distillation curve made for four strokes and would make two strokes run less than perfect, so I am supprised by your results.
Chad put them against each other on a dyno and they were almost identical in HP with some deviations at certain rpms. I can only report my findings. They also carry 112 Sunoco. That 110 purple-colored Sunoco smells good with Motul.
 
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I can only report my results. I repeated it several times with the same results. My limited tests showed you need at least 205 compression or more to see any benefits. I have a compression ratio chart that has been 100% accurate.

I really wanna see first hand one of these saws blowin over 200 psi smoke one in the 180-190 range , i havent yet..the best runners ive had my digits on were in the 180 range.
 
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I really wanna see first hand one of these saws blowin over 200 psi smoke one in the 180-190 range , i havent yet..the best runners ive had my digits on were in the 180 range.
I don't like compression in saws I want to be fast. (there's a difference in fast and usable) my 4 and 5 cube saws are blowing around 140lbs
 
bwalker
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I really wanna see first hand one of these saws blowin over 200 psi smoke one in the 180-190 range , i havent yet..the best runners ive had my digits on were in the 180 range.
I really wanna see first hand one of these saws blowin over 200 psi smoke one in the 180-190 range , i havent yet..the best runners ive had my digits on were in the 180 range.
Pumping loss related?
 
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