Oil premix ratios and burn rates flashpoints etc.

[woundedwarrior]

This is just another topic I would like to see some true numbers on.
Of course we all want to run a sufficient mix to support to the motor at its peak rpm that it may be ran at from time to time. But also don't want to overdo it so to speak and foul plugs often.

But this is what gets me thinking in terms of ratio
We all know what sticking a match to spoon full of gasoline will do...
We also know what happens when you do the something to a spoonful of 2 cycle oil...

So theoretically the ratio of oil to gasoline should affect its flashpoint ....
Say 32:1 has x amount flashpoint and is slower to burn
Say 40:1 has x amount flashpoint and is considered mid speed to burn
And lastly 50:1 has x amount flashpoint and has the fastest of the 3 to burn.
Now take all this and think about it ...And again I may be way off here..
But I would think oil ratio mix would be a large overlooked part of the equation when figuring octane numbers a motor actually needs to support its higher compression or timming....Not that higher ratio of oil gives more octane to gas but slows its burn rate which in affect is almost the same thing..
This could be used for people also that get stuck somewhere where's there only 91 at the pump instead of the 92 they theoretically need..

Again this is just an old jar heads rumblings ..And thoughts..
Maybe someone in the know will chime in..

[j_martin]

I think your basic premise is flawed on a couple of points.
1. Flash point is determined by the availability of a volatile fuel in sufficient quantity, as well as it's vapor pressure. That component is available regardless of the amount of oil. (within reason)
2. Once lit, the oil burns faster than gasoline. Octane is a measure of resistance to detonation, which is actually the opposite of that. (higher octane = slower burn) More oil may reduce octane if anything. I don't think the amount of oil actually makes much difference in this, except for the following.

The factor that sends more engines to the graveyard than any other in this is that you have to compensate for high rates of oiling by increasing the metering (jet in a carb'd engine). The fuel with more oil will flow through the jets less because of increased viscosity, and may cause the burn to be too lean and overheat the combustion chamber. In other words, more oil isn't richer, it's leaner as far as fuel goes. In trying to compensate for low octane fuel, this would be counter productive.

[rude tim]

MotocrossAction did a study using a 2 stroke motorcycle on a dyno and they found that the engine made more power at 16:1 vers 32:1. More oil better ring seal and longer burn. The problem comes with the ignition having enough spark to fire the mixture which resulted in a few fouled plugs.

[Slimm]

MotocrossAction did a study using a 2 stroke motorcycle on a dyno and they found that the engine made more power at 16:1 vers 32:1. More oil better ring seal and longer burn. The problem comes with the ignition having enough spark to fire the mixture which resulted in a few fouled plugs.

Did they say how much more power? I would be interested in knowing.

Slimm

[Glasstream15]

I remember from my RD350 days that using just oil injection I was running even or slightly behind a couple of Honda 750 Nighthawks. When I went with 1 1/2 ounce per gallon in the gas plus the oil injection the Hondas got to enjoy the delightful smell of the burning oil and the sweet sound of the stinger equipped chambers. That was in quarter mile runs. Top end they'd still take me because I topped out just under 120 and they could go where they didn't want to on top. Plus I had less "piston slap" at low revs with extra oil. And we had LEADED hi test gas.

[powerabout]

I think more oil leans out the engine not because of viscosity but because you are replacing fuel with oil.
That bike test mentioned above was stopped at 16:1 as they didnt have any bigger main jets to compensate.

What we need to find out is the properties of the oil then we up our knowledge.
We know the burning properties etc. of straight oil?
I am thinking to heat it a bit and run it through a diesel injector tester with a lighter under the injector..

( the spontaneous combustion temp of oil is 1/3 of gas, drop some oil on your hot turbo and you have a bonfire, drop gas on and no way will it light even with a red hot turbo, yet with a spark its opposite numbers)
here's some numbers from Castrol 2t the one that is biodegradable ( in fact I thinks its the only biodegradable bia twc3 oil)




Density at 20ºC
0.895
Viscosity at 40ºC, mm²/s
49
Viscosity at 100ºC, mm²/s
8.4
Flash Point (closed) ºC
222
VI
149
Pour Point ºC
-39

[woundedwarrior]

After further study I have read that the higher the oil to gas ratio does lower octane but does make better ring seal hydraulics.. I will try to post the links later but none the less interesting thoughts and theory's..
Where I'm at in my latest lill project is a stock unmodified 225 Promax..other than the oil injection removed And pre mix 40:1 klotz supertechniplate 160 lb compression heads and timing advance module removed at set at 25°BTDC ..@Wot..the stock box seems to be very rich ...I'm running 93 octane gas and planned on boosting it with toluene.But was in able to pick some up yet ..So I had done a lot of research on private and independent tests on octane boosters and had heard and seen a lot of good things said about the nos octane booster racing version and saw that it raises octane an actual 30-60 points depending on the mix that meaning 10 points = 1 full octane number ....So I have an estimated 95.5-96 octane in the tank right now.. So I guess I'm gonna head back out in a few with fresh sets of plugs ..Make hard runs shut her down pull and read plugs and start advancing the timing deg by degree till I get them looking a (safe) but good place..Then I'm going to experiment with stand alone nock sensors with idiot lights on the dash..This is just a motor i plan on doing exploratory sugery on this winter anyway motor