What oil is best? and what ratio?

[junkman]

Ever mix race with the pump gas for the bikes Ben ?

 

[bwalker]

Ever mix race with the pump gas for the bikes Ben ?

Yea, and the same with AV gas. It's kinda of a circle jerk though as you never get real consistent results vs pure race gas.

 

[Keith Gandy]

That would depend on the engine parameters.
However, as it pertains to OPE, likely never.

A ported 066 with 240lbs of compression with timing advance?

 

[junkman]

Was told not to run av gas in the bikes because it was designed for higher altitude ?

 

[mdavlee]

Well I used all but 4 oz of the fuel mixed with HP2 around 20:1. Rpm out of the wood dropped when warmed up about 400. I reset the saw to 12.8k for the first cut. I checked right after a cut and it was the same. Temperature had dropped in the mid 30s with a nice breeze. I timed the first cut and it was 6 minutes 35 seconds with the time to walk to the log and start and time to go back and cut the timer off. The phone was on the truck 8' away so it was maybe 10 seconds total. Power was about the same as yesterday by the time of the cut. The top of the piston was wet on most of it. I only idled it maybe a minute since it was cool and only one cut.

 

[bwalker]

Was told not to run av gas in the bikes because it was designed for higher altitude ?

Doesn't hurt anything, just has really crappy throttle response and seems to impact hp as well.

 

[bwalker]

A ported 066 with 240lbs of compression with timing advance?

What's the compression ratio?...

 

[Keith Gandy]

Well I used all but 4 oz of the fuel mixed with HP2 around 20:1. Rpm out of the wood dropped when warmed up about 400. I reset the saw to 12.8k for the first cut. I checked right after a cut and it was the same. Temperature had dropped in the mid 30s with a nice breeze. I timed the first cut and it was 6 minutes 35 seconds with the time to walk to the log and start and time to go back and cut the timer off. The phone was on the truck 8' away so it was maybe 10 seconds total. Power was about the same as yesterday by the time of the cut. The top of the piston was wet on most of it. I only idled it maybe a minute since it was cool and only one cut.

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So Mike u still prefer the super techniplate or kl200 for milling?

 

[mdavlee]

So Mike u still prefer the super techniplate or kl200 for milling?

Yes. 20:1 is too much oil for the saw with HP2. I ran 25:1 in some milling with R50 and it wasn't that wet on the crown. It was summer time too.

 

[Keith Gandy]

What's the compression ratio?...

Heck Ben do u really think anybody on here is gonna measure trapped and static volumes??? Lol!! The way on here is go for topend compression and pull a ratio out of the air and assume they need more octane

 

[Moparmyway]

What's the compression ratio?...

Welcome Ben ............. good to see you here

 

[jake wells]

a little OT i tried some belray H1R in a 2 stroke pusher over the summer and it seemed to run a little better than others i have mixed at 32:1
the compression ratio on the pusher is 5.5:1. i also noticed the muffler had oil puddled in it as before it didn't.

 

[Ron660]

Most 110 fuels I have seen have distillation curves totaly wrong for a two cycle. So it makes sense 110 would perform poorly. AV gas is in the same boat IME.

Only way to know is to conduct timed cuts with YOUR saw. It's that simple. You can theorize all you want. Test your saw then you'll know. I deal in facts not theories.

 

[Ron660]

I must say that 7910 would sing through there easily!

Couldn't touch your MM ported 390.

 

[Keith Gandy]

Couldn't touch your MM ported 390.

U would be shocked how strong that 7910 is

 

[Ron660]

Most 110 fuels I have seen have distillation curves totaly wrong for a two cycle. So it makes sense 110 would perform poorly. AV gas is in the same boat IME.

I'm not disputing your statement I'm just surprised 110 was faster in my saw. I'll test again to confirm my findings. I forgot what racing you requested for my saw?

 

[Ron660]

Ok lets start simple for everyones sake. When do u need high octane say 110?

When you have a MM 660 with compression over 210 psi....lol

 

[Keith Gandy]

When you have a MM 660 with compression over 210 psi....lol

If u measured the top and bottom volumes to get a true ratio u would be suprised how little of a ratio u really have on that saw.

 

[mdavlee]

Treemonkey figured some at 7.5:1 or so I believe.

 

[Keith Gandy]

Treemonkey figured some at 7.5:1 or so I believe.

That sounds realistic Mike instead of like 12 or 13 to1 like alota people think