Octane and oil ratio for 220lbs compression

**Dave S** · 12-04-2019, 10:27 AM

.That fine young layd could be our next new world leader........unless hillbeast stops her.......SAVE us.

**tunnelmike** · 12-04-2019, 11:39 AM

Motv I get that. I should have worded it differently. This motor should get into the 10s with a small wheel

Chaz , mine were CR 250s with 112 mixed with Maxima 727 castor. I miss the smell ! Ran the Maxima in my first boats when I was still racing Motocross because it was convenient. Switched to Klotz and never had a problem.

Thanks Eric , I will run down some R-50

**Mrzip** · 12-04-2019, 12:09 PM

I didn't have a Dirt bike

**Chaz** · 12-04-2019, 12:43 PM

Even though it was "fake news" .. ( for those who watch street outlaws ) When Kye Kelly made the "pit call" for some "blank nitrous jets" (not drilled) he did so to make everyone think his motor was hurt.
Why would it matter if he had a pinched ring land ... cuz everyone knows that if oil gets in the chamber .... it will kill the octane, and as it's said ... burn that ***** up. Unfortunately, I know this first hand ... the results are not pretty .

Every nitrous racer I know builds their motors with wide 3/16 th's standard tension oil rings and a Napier cut second ring, both of which are made to control oil. The top ring is moved down on the piston and uses a "Hellfire" tool steel ring designed to deal with the heat and not lose radial tension.
They also use a Viton type seal on the intake valve to control the oil and either use an O-ring or nothing on the exhaust stem, to keep it wet while dealing with the extreme heat while "runnin it out the exhaust" from retarded timing.
Why does this all matter ... oil kills octane. The synthetics aren't as bad as dinosaur blood. But once again .. too much of a good thing , aint so good ...

http://www.corboatracing.com/octane-...rcury-outboard

Whatttt .. no dirt bikes. Just think of all the hospital visit's you missed out on ..

**Motv18** · 12-04-2019, 04:03 PM

Interesting Chaz. Learn new stuff every day.

**tunnelmike** · 12-04-2019, 07:34 PM

This guy has some knowledge !! I'm amazed you can retain so much Chaz. Not in a bad way , more like a "how can he fit all that in there " kind of way ! ��

**Chaz** · 12-04-2019, 11:25 PM

Leaded Fuel ... Dunnn It ..

I remain teachable. Only stupid people are the ones who already know everything ..

I liked this comment (the second one down) it seems somewhat valid . But we all know , more oil , more smoke .. so it does find a way into the combustion process.

The Opti's and 2002 and up EFI's with the electric oil pump idle at like 250 : 1 and run WFO at 40 : 1 If I'm not mistaken. 6000 RPM motor, but those numbers seemed pretty insane to me .. till I got use to it .. LOL . All of em I yanked apart always seemed pretty wet ...

For your 10,000 RPM piece .. I'd follow Eric's recommendation, he hangs out with some pretty fast company ..

I just looked up the question of adding oil to gasolene and it's effects: the answers were mixed! OMC engineers found that adding oil increased the power output at high rpm. Very little oil reaches the combustin chamber, it is used up as a lubricant before it reaches the point of combustion EITHER WAY, THE DIFFERENCE IS NOT MUCH AND IN MY HUMBLE OPINION, MORE IS BETTER TO A POINT AND MY POINT IS 24:1ON A RACING ENGINE. ROD

There's that .. "up to a point" thing again .. LOL, I guess moderation is key ..

**Markus** · 12-05-2019, 05:01 AM

As to Greta, she does have Asperger's syndrome, so she her brain is not organized like most people's. If she hadn't been indoctrinated in the Swedish school system where the vast majority of teachers vote for the Green Party (and, btw, the vast majority of Green Party voters in Sweden are teachers), she could have become a good engine builder instead of a climate activist.

As to oil ratio, the way to think about it is how much oil to feed the engine per revolution. At 10000 rpm, the fuel curve in a 2.5 liter Mercury will be very lean, and to get the required amount of oil per revolution, the oil to fuel ratio will need to very high. In addition, in any case, I hear of offshore racers who claim that a secret to their success has been very high oil ratios. So don't be afraid of oil.

As to leaded fuel, the sad truth is that Chaz' brain would have contained even more knowledge if he hadn't been exposed to leaded fuel when growing up. And that applies to all of us who were born before leaded fuel was phased out. So do be afraid of leaded fuel.__PRESENT

**tunnelmike** · 12-05-2019, 05:29 AM

I've heard from several sst120 racers the higher oil ratios made more power but they didn't have v-boxes and the other data measuring devices we have now. Hard to say. I just want it to live.

**Motv18** · 12-05-2019, 11:14 AM

I did find a Husqvarna oil test of 24:1 vs 50:1. Lost the link sorry. The results were 24:1 had less wear on the piston skirt, but same on bearings. They concluded that 24:1 precipitation of oil in the bore was greater but provided nothing to the bearings since 50:1 coated them fully.

Interesting enough the same test between castor, synthetic, and normal oil showed castor provided the best protection then synthetic 3rd being normal oil.

The only problem im finding is the 72 octane part, and it got me thinking of % vs. aki. In the % rating anything would lower the octane rating (even toluene) as it diluted the % of octane. At 20:1 that easy make 72. Modern methods are saying -2 aki I can live with that.

**90 5.0** · 12-07-2019, 11:31 AM

Originally Posted by tunnelmike

I've heard from several sst120 racers the higher oil ratios made more power but they didn't have v-boxes and the other data measuring devices we have now. Hard to say. I just want it to live.

I know some old sst guys that ran around 18:1, said same thing.

I tried it and didnt see anydifference and settled around 28:1

**tunnelmike** · 12-07-2019, 11:54 AM

Turning how many r's ? After a few discussions 10500-11000 should be possible. Im going to start with c12 and R-50 at 25:1 and go from there.

Going to the Winter Nats ? Mike

**Motv18** · 12-07-2019, 07:40 PM

Sounds legit

have fun and luck.

**H2OPERF** · 12-09-2019, 08:27 AM

McCulloch did tests way back and said power increases were shown with ratios down to like 15:1... I like the R50, I just ordered 4 more gal last week, not sure how long its on for but Klotz has a holiday promotion free shipping and 30% off came out to $190.00 for 4 gals.. Another thing about R50 it's really good against rust/corrosion when the engines not being used, you will find when you pull one apart with this oil every things coated and almost sticky feeling. I had rust issues down here with some other synthetics not going to get into an oil war lol, but r50 is good stuff, motul 800 road race is too but really expensive.

**Chaz** · 12-10-2019, 09:51 AM

Originally Posted by tunnelmike

Turning how many r's ? After a few discussions 10500-11000 should be possible. Im going to start with c12 and R-50 at 25:1 and go from there.

Going to the Winter Nats ? Mike

Excellent starting point ...

Two strokes are amazing in the fact that they have the capability to "over run" the point of peak power. Any drag racer I've asked "Where does it quit pulling" they usually answer (or show dyno sheets) where they nose over between 8000 - 8500.
Then I ask, "why don't you prop it to cross at 9000" the standard answer is .. then it won't work off the bottom.
I understand that E.T. is made early ( a big part of why the stick mids came about) but it killed me watching Comp Eliminator cars be in high gear with the tongue hangin out well before the 1000' cone, and laboring to make it to the stripe. Just as it does now to hear about spinning outboards that far past the peak.
The "next breakthrough" will come from the guy who can "work both ends" of the track ...

Chaz = just thinkin out loud ...