Commandos and Higher Octane Gas

A few years back I checked out the pure gas website and found there were two stations listed in Pueblo. So I headed over to the "Black Mule" and got a gas can full and took it home and tested it. It showed around 7% alcohol. I went back to the station and inquired about it and was told that they didn't have non-alcohol fuel anymore. When I ask about the sign clearly stating no alcohol they said they just never got around to taking the sign down and that non-alcohol fuel had not been available in Pueblo for a couple years. About a year later the sign finally came down. Obviously no one monitors what is being sold. Jim

hobot said:

Hehhehe>LOL pete.v you nailed ole Ludwig claims down good. His featherweight wonder would be a loaded down fuel tanker if what he stated was so over the distances he's proven to do in wonderful regions. Funnier yet is if Ludwig has tuned up engine to take advantage of extra octane/detonation resistance in low oxygen altitudes he'd experience same as comnoz did with his EFI dialed in just right to point that one event of questionable 87 octane slapped his engine apart on a tour trip last year. Peel will be immune to boozed/watered or poor fuel quality as can just select spark timing and throttle ease to get to better fuel station. If ya look up the octane boosters beyond their own advertising you'll see at best they can raise octane a point or two.

http://www.wallaceracing.com/octane-mix-calc.php

http://www.bazellracefuels.com/Calcs/OC1.htm

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Walter Mitty strikes again - the bullshit never stops on this forum. I suggest you actually try doing some miles on your bikes rather than speculating to the nth degree on what may or may not happen due to quality of fuel, preferred spark plug, oil viscosity, tyre sizes, correct shade of black etc etc etc etc. 10,000 miles last year between mot's on cheapest unleaded with ethanol purchased from garages in England, Wales, Scotland, France, Germany, Austria, Isle of Man. I'm off on a 3,000 mile trip through Scandinavia in June. Forum experts do no more than a few hundred miles a year. Sad but true.

How come you're on the forum.
Bon voyage.

comnoz said:

A few years back I checked out the pure gas website and found there were two stations listed in Pueblo. So I headed over to the "Black Mule" and got a gas can full and took it home and tested it. It showed around 7% alcohol. I went back to the station and inquired about it and was told that they didn't have non-alcohol fuel anymore. When I ask about the sign clearly stating no alcohol they said they just never got around to taking the sign down and that non-alcohol fuel had not been available in Pueblo for a couple years. About a year later the sign finally came down. Obviously no one monitors what is being sold. Jim

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Similar situation here - a local garage (on the A6 south of Lancaster) is on the 'leaded fuel supplier' lists for various classic club websites, and their sign confirmed the fact, but I just got a vacant stare when I enquired at the counter (it happens to me a lot, but this time it was in response to 'where's the leaded patrol pump?').
The sign has now been replaced, so no leaded fuel here anymore

A small franchise, Murco sells only ethanol-free fuel, but doesn't advertise the fact (not tree-hugging, politically correct to do so!)
Combat runs just great on their fuel, and my fibreglass tank approves, too, although its lined with Tank Care Products resin.

Quick question: how can a non-chemist check for booze in fuel?

Last few seasons only non ethanol in Arkansas is some 91 & 93 octane which is rare outside of a big city. Wes and I usually get 91 spiked gasoline now but have been rescued a number of times with stale lawn mower gas or even oil mixed chainsaw fuel w/o any problem on his '71 or my Combats. Wes's fiberglass HyRyder tiny tank was Thick coated with Caswell's back in '04 and so far so good even with a crash leak in tunnel he JBW'd a few years ago. I caused it on parking lot exit Grit going about 30 when the drum brake self engergized suddenly and tank slammed on my leg protecting its outer gel coat. I have asked INOA, NOC-UK, Brit Iron and this forum for examples of detonation conditions experienced to guide me on Peel to only get a few over heated racer examples or out of time and tune errors on road bikes plus comnoz EFI event last year by bad Texas gas. So please report here of any other detonation events and conditions to learn form. There is a fuel station in big city here that has 112 Sunoco at the pump and 116 inside. I'll start off tuning Peel with the 112 then work down to 93, 91, 89 and 87 listening and looking in but for boost, water or water/methanol spray should give excess detonation reserves. Nortons are too noisy for knock sensor protection unless microphone allows pilot to hear it and even modern cars are too noisy in the hi freq at hi rpm so knock sensors bypassed in those states.

ludwig said:

hobot said:

.. Peel will be immune to boozed/watered or poor fuel quality ..

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By the time your mythical miss Peel wil be on the road , there will be no more fuel to burn ..

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:lol: :lol: :lol: Mythical Ms peel........ Dont worry Ludwig there is always plan "B" if there is no fuel....

ludwig said:

hobot said:

.. Peel will be immune to boozed/watered or poor fuel quality ..

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By the time your mythical miss Peel wil be on the road , there will be no more fuel to burn ..

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I suspect that will never be the case. There are ways around the oil crisis. If the oil companies already have catalysts which help synthesise petrol from carbon dioxide and hydrogen, they won't be making much noise about it until the optimum time to exploit the technology. The technology would probably be an extension of Fischer Tropsche synthesis.

Part of the said 850 development was for international touring , so engines that wouldnt self ingest on Pakistani or Botswanian petrol ensured 8.5 : 1 C.R. ensued . So they said .

Where theres a will theres a way , or is it S T I L L .

B+Bogus said:

Quick question: how can a non-chemist check for booze in fuel?

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I have a full fuel testing kit left over from spec fuel racing go karts many years ago.

There are simple alcohol test kits available. You simply mix the fuel with water. Alcohol will be absorbed into the water and will not show as fluid volume.
IE, If you mix 100ccs of water and 100ccs of fuel you should end up with 200ccs of mixture. If you only end up with 190 ccs of mixture then 10ccs was alcohol. Jim

B+Bogus said:

Quick question: how can a non-chemist check for booze in fuel?

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here is one way:

http://www.fuel-testers.com/order.html

That is a nice site and product. The home page has a lot of good info:

Winter Storage:
For prolonged gas storage, it is always safest to leave gas tank empty, when E10 is only gas type available in your area.
E10 gas will only remain stable (water-free) for a maximum of 3 months, when stored under ideal low humidity conditions.
Important: No gas additive can prevent ethanol's natural ability to attract/absorb or remove water in a sedentary engine. Products such as Stabil, only "perk-up" stale fuel by increasing energy content; They do NOT prevent or remove water from gas tank.

By the time your mythical miss Peel wil be on the road , there will be no more fuel to burn ..

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Ugh that is a valid point of concern to to me too, plus me surviving long enough in functional condition too. My mower repair and hop up has priority this season with octane being some concern too.
http://gardentractorpullingtips.com/index.htm
http://gardentractorpullingtips.com/a1engine.htm

worntorn said:

Common thinking is, run high octane, big advance, go like gangbusters. Fact is, regular low octane gas has more energy per unit than high octane does. Octane is a necessary evil to prevent pinging, but due to the power lost in high Octane fuels( they burn slower to avoid ping) best to only use as high as needed.
Same with ignition timing. We used to advance to ping then back off a little, so run all the advance possible. This was wrong way round, now it is retard until power loss is seen on dyno, then advance back a touch.
So run the lowest octane gas you can safely get away with and run the least advance you can get away with, that is where Max power (and safety with the timing) is with those two variables.

Glen

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+ 1

For years I ran my race bike with petrol station pump NZ 96 octane gas with up to 10 % ethanol. 10.2 :1 compresssion ratio.

I tried 100 octane Shell #1 race gas on the dyno back to back with the pump gas. Not even the thickess of a line difference in result. Mixture settings ok in both cases.

The only measurable difference was in my wallet

Run the lowest octane your bike can handle. And read Gordon Jennings to tell you how to read plugs to get your igntion timing correct. This is worth much more than all the 110 octane gas you can buy!

There is nothing to gain by using higher octane than needed. The possible gains would be from going to a higher compression ratio that would be possible with higher octane fuel.

I was surprised a few years back when I was tuning a guys race Norton on the dyno. He had brought the bike to me with a tank of av gas that he always used in the bike. It was running powermax pistons are around 10-5 to 1. After several runs and getting the jetting and cam dialed in we ran out of fuel.
We went down to the corner store and got a can full of premium fuel and saw a gain of around 4 horse on the next run. He never bothered with av gas after that. Jim

johnm said:

worntorn said:

Common thinking is, run high octane, big advance, go like gangbusters. Fact is, regular low octane gas has more energy per unit than high octane does. Octane is a necessary evil to prevent pinging, but due to the power lost in high Octane fuels( they burn slower to avoid ping) best to only use as high as needed.
Same with ignition timing. We used to advance to ping then back off a little, so run all the advance possible. This was wrong way round, now it is retard until power loss is seen on dyno, then advance back a touch.
So run the lowest octane gas you can safely get away with and run the least advance you can get away with, that is where Max power (and safety with the timing) is with those two variables.

Glen

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+ 1

For years I ran my race bike with petrol station pump NZ 96 octane gas with up to 10 % ethanol. 10.2 :1 compresssion ratio.

I tried 100 octane Shell #1 race gas on the dyno back to back with the pump gas. Not even the thickess of a line difference in result. Mixture settings ok in both cases.

The only measurable difference was in my wallet

Run the lowest octane your bike can handle. And read Gordon Jennings to tell you how to read plugs to get your igntion timing correct. This is worth much more than all the 110 octane gas you can buy!

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I agree with that. The only time I would set up ignition timing and jetting for high octane, is if I was racing and had increased the comp. ratio .
If you are set up to get the max out of high octane fuel, if then you get a tankful of lower grade, the bike will often lose it's edge and ping, and you can get motor damage. . If you are set up to get the max out of low octane fuel, and then get a tank full of high octane, all will be well.

Hi all, and so "octane booster" should be in the same range.......?

I have seen the same thing in some guy's drag racing. he decided that if it ran good on 93 octane pump gas it will go even faster with the 110 octane race fuel. the car slowed down with his little experiment. if it runs fine on 87 octane than 89 as a just in case but 93 is a total waste of money and you might even see a small drop in performance.

comnoz said:

There is nothing to gain by using higher octane than needed. The possible gains would be from going to a higher compression ratio that would be possible with higher octane fuel.

I was surprised a few years back when I was tuning a guys race Norton on the dyno. He had brought the bike to me with a tank of av gas that he always used in the bike. It was running powermax pistons are around 10-5 to 1. After several runs and getting the jetting and cam dialed in we ran out of fuel.
We went down to the corner store and got a can full of premium fuel and saw a gain of around 4 horse on the next run. He never bothered with av gas after that. Jim

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The technical monitored path is to set ignition time for highest mean brake power pressure to occur just after TDC then work up octane till adequate anti-detonation. Some older flat head side valve engines appear to be helped by over dosing octane so it burns the whole way down and help jets more exhaust out faster. I'm a propane guy so itching to try that vapor fuel for fun. Here's a long article to wrap heads around on octane vs CR/boost vs spark and type of plugs and temp inside or outside a dyno room etc etc.
http://www.fnptuned.com/street-tune-vs-dyno-tune/

comnoz said:

There is nothing to gain by using higher octane than needed. The possible gains would be from going to a higher compression ratio that would be possible with higher octane fuel.

I was surprised a few years back when I was tuning a guys race Norton on the dyno. He had brought the bike to me with a tank of av gas that he always used in the bike. It was running powermax pistons are around 10-5 to 1. After several runs and getting the jetting and cam dialed in we ran out of fuel.
We went down to the corner store and got a can full of premium fuel and saw a gain of around 4 horse on the next run. He never bothered with av gas after that. Jim

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A few years ago, I took my GLHS turbo car to Las Vegas for two days on their classic track; I was running about 15 pounds of boost on a full tank of 91, then as I burned it off, for "safety", I added 100 race gas that they were selling at the track AND I turned the boost up to maybe 20 pounds; power improved and EGT fell too . . . . but . . . . . when I added 100 a second time, as the ratio of 100 to 91 really climbed, she started stuttering . . . . big power loss . . . . . OMG! I thought I'd cracked a ring land . . . . but what I figured out was that the 100 was putting the fire out; it quenched combustion too much. Now I had a tank of bad gas! Solution - turned the boost up some more! She liked it. Fun times pushing/chasing Fords.

So . . . . for our bikes, what I learned from that, is that what fuel to use is a complex, a complex of compression, valve timing, and ignition timing.

For Hobot's blown beast, include boost in that complex.

Alrighty John thanks for practical pointers on taking advantage of extra octane other wise wasted. From Tom Drouin and magazine edititors testing to comnoz and Bruce McGregor all they say the blower won't make much or any boost-performance unless throttle snapped to suddenly load engine so I hope to ride around most the time with drag cam & 10.5 CR on 87 octane but will have triggers to ser spark curve on retard slope and anti-detonation fluids. This subject sends me into deeper search binges a couple times a year and recently saw a reference that says EFI tends to more detonation prone-ness over carbs d/t lack of cooling fuel in the manifold air flow. MIght of been a factor in comnoz starting on a new engine last year with boost in mind. Varrommm VarrRROOM KABOOM.

Would be fun education to list as many anti-detonation factors Commando could do that don't hurt power just help it. One un-recognized or un-reported feature in the passive reed valve like comnoz offers and active pressure suckers is better ring oil control. Ya know what an oil fired diesel know for.