High Octane "Super Unleaded" makes massive difference!?

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

I am certain it makes a big difference, running 97RON UK fuel instead of 95.

I notice a little smoother mid speed cruising(45-55) and better pickup, but mostly where I notice it, is that the bike makes much less mechanical noise and heat!...the noise I am certain of, and the noise on my bike is usually a result of heat. But without a thermo, its a guess based on the noise Smile

I took the bike through London, several times, on higher then lower octane , before I got to cruise home on the main roads, the bike was very lumpy and nosey on the lower octane.

I am definitely gonna try an additive, as I was told these bikes were originally run on UK 4 Star which I remember as being 100RON!

xsjohn

Wait till it's 20 percent or even 30 percent alcohol.......the cylinders will start to glow...... Laughing

xsjohn

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

So what your sayin' John is that higher octane makes it run hotter?

Not Cooler?

I thought that for a given compression ratio, an increase in octane will cause a faster burn, and less heat?

xsjohn

Alcohol will make it run hotter...........the more the hotter kinda thing.....10%.....20%.......30%.......ect.......they will basically screw us into a hot box........at that point there will be lots of 8-1's......or nun to 1's.... Laughing

High test should run cooler.........but it probably has alcohol in it too in most places.....and all places soon.....then the percent will start going up....... Evil or Very Mad

The higher the octane the slower the burn..........

The good news is I found around town the 8-1 runs cooler....the bad news is on the highway at express speeds the temps were the same as before.....and still running with not much throttle so it isn't really working much harder........

Good news Mikes 750 at 7.5-1 with the bigger fins will save me at 20-30 percent alcohol.........well hopefully......or the talk will change to """"look how I water cooled mine""""""then the mods will make since.......at least to me...........bet the tac drive would run a small water pump....but once the cylinders are enclosed the pump and radiator better work......and a fan would require a bit better electrical system......dear god what's ahead......will require more thinking....or more fixing......... ?

xsjohn

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Well then I wander if some of the noises I was getting where to do with pinking or ringing, because they do lessen substantially when I use the higher octane pump fuel.

Havent tried an additive yet..

Perhaps its possible someone (PO) has skimmed my head? The motor still produces a huge deflection on the comp meter.. Right at the top of the green line..about 14bar? 190 PSI?

xsjohn

Mine stock the compression always ran at 150 PSI.........you are definately up there buddy....now I am running 135 PSI.....

xsjohn

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

ummm...

I have to say that this bike always ran better slightly richer than stock (aside from pilots) and it does a 100mph with relative ease. (just make sure you wear a diaper:-) ) The ports look like they have been cleaned out, maybe blue printed? Seems like I might be running a mildly tuned motor..

The pods and tuned near straight thru's made another big difference.

Which maybe explains the performance increase from a VERY slight advance and high octane gas?

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Well then I wander if some of the noises I was getting where to do with pinking or ringing, because they do lessen substantially when I use the higher octane pump fuel.

Havent tried an additive yet..

Perhaps its possible someone (PO) has skimmed my head? The motor still produces a huge deflection on the comp meter.. Right at the top of the green line..about 14bar? 190 PSI?

jayel

or high comp. pistons definatly want to be running hi-test fuel that noise your hearing (spark knock) is pre-ignition, maybe your timing is to advanced? www.misterfixit.com/deton.htm

xs1961

Well , I tried 98ron again today after reading jakes post ..No dicernable difference between that & the 95 I always use apart from the hole in my wallet !

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Dude...

You know me, I might be imagining it.

But I've always had this "zip" or "ring" noise to my engine.

When I use the expensive fuel its virtually inaudible. It might run just a little smoother, but thats like top gear 45mph slow cruising..60 at most...

xs1961

Jake, just because my motor seems unaffected doesnt mean it wont help yours,no two engines/set-ups are identical.. Different combinations in timing, ign systems, plugs, compression ,carbs etc can all affect/be affected the juice we put in.. (Mine runs on 34mm vm's with retarded timing)
I used to put a tablespoon of AVGAS in my bikes years ago - that really used to stop the pinking !

thorshammer · Full Member Joined: Dec 12, 2008 Posts: 58

John I don't think the alchohol will make it run hotter but as you add more to your fuel it will start to lean your mix out causeing it to run hotter. You can run straight alchohol if you increase the diameter of the jets by about 40% this means you will increase the fuel flow to just about double, now the motor should run cooler and you can raise your compression back up and regain your lost power. Just think we may all be soon able to burn twice as much more expensive fuel to go the same distance as we do now, but this will also drive the cost of beer, wine and liquor up. Maybe if we start on gas and get it hot we can then switch over to heated veggie oil like the old tractor on the farm?

xsjohn

Surely I am not the expert but from what I read alcohol has no lubricating qualities......where fuel does to some extent..........cylinder wash may be more of a problem as the alcohol percentage is raised....then what...add oil to the gas......which will lower the octane some more..........no doubt this issure will have to be addressed as the percentage goes up......

Maybe someone is in the fuel business and can add to this discussion......

xsjohn

xsjohn

Here is something on alcohol.....methanol (I found this article on the web)

Taking the Mystery Out Of Drag Racing With Alcohol (or maybe just running it in the future) (or adding alcohol to gas...ethanol) (percent of MJ increase would change per percent of alcohol)

I have run across more racers than I can count who have said to me, "I don't know anything about racing with alcohol so I race with gas." I wanted to write this article to take a lot of the mystery out of the subject as racing with alcohol is really not that difficult. I started racing with methanol back in 1985 after Danny Bastianelli, a good friend of mine, talked me into it. At that time we made tons of mistakes and learned a lot the hard way, but we also ran pretty quick.
So,,what is it? Methanol, racing alcohol, is comprised of one carbon atom, one oxygen atom and four hydrogen atoms (CH3OH), a clear, very toxic liquid fuel formed by catalytically combining CO with hydrogen in a 1:2 ratio under high temperature and pressure. It melts at -97.8°C (-144.04° F) and boils at 67°C (152.6° F). The boiling point is important so remember it for later in the article. Methanol mixes and absorbs water very easily.
These are all important considerations that you must take into account before beginning to race with Methanol"

1.) Methanol makes approximately 15% more horsepower than racing gas. You will go quicker immediately. It is also a very forgiving fuel and much more consistent as it is much less vulnerable to weather changes than gas.

2.) Slightly rich methanol engines typically run with much lower exhaust gas temperatures than with a gasoline engine, while the exhaust gas volume is higher. On the top end with methanol, a 1250° EGT is expected vs.1400° to 1500° for gas. The result is much lower coolant temperatures. On a typical run, pull out of staging at 150°, stage at 160°, go through the lights at 180° and cruise down the return road at 160°. Overheating is an issue of the past.

3.) Methanol evaporates very quickly when directly exposed to the atmosphere. As a result, fuel jugs and fuel caps must be kept closed when not transferring fuel.

4.) Methanol is corrosive so keep your fuel system full with fuel or it will evaporate, oxidizing certain types of metal such as pot metal, aluminum or steel (not stainless steel) and will dry or harden rubber seals and hoses. Corrosion can be kept to a minimum by mixing 2 oz. of top oil to each 5 gallon jug of methanol. This amount of top oil will not effect performance but will adequately lubricate the fuel system and the cylinder bores. After you are finished racing for the day, liberally spray your induction system with WD-40, turn the motor over for 5 seconds then repeat the process 2 more times. This will protect your carburetor or throttle body and keep any rust from forming on the cylinder walls.

5.) You will use almost twice as much methanol as you would racing gas. The optimum air/fuel ratio for methanol is 6.4: 1 while gasoline is 13.2:1. As a result, you need to be able to flow enough fuel so as not to starve the motor. If racing with a carburetor use a high flow electric fuel pump such as a Magna Fuel or Barry Grant or even a mechanical belt driven pump with a 10-AN supply line.. If you use an electric pump, you need a good quality bypass regulator (I recommend only the Magna Fuel) set @ 8 lbs. adjusted with the motor running on idle. A bypass is extremely important because methanol boils at 152.6° F and it doesn't take very long for methanol under a lot of pressure to reach that point. A 750 cfm Demon for my 370 cubic inch small block would use 94 jets on gas or my 775 cfm Demon on methanol would use 180 jets.
I learned the hard way that the ultimate fuel system for methanol is a Ron's Flying Toilet. It's worth .2 in ET. My 385 small block uses #35 injector nozzles and a .086 bypass pill.

6.) Seeing that you are pumping twice as much fuel through the motor as with gas, if you aren't careful, the oil will easily get polluted with fuel and water. To cure this, if you race with a carburetor, use a 2" spacer between the intake and the carburetor with a 1/2" NPT hole in the front of it with a 8-AN fitting. Run a 8-AN hose to the driver's compartment with a ball valve at the end that is easily accessed by the driver. Install a pyrometer in the car with an EGT sensor in a header 1" from the exhaust flange of a front cylinder. Whenever you are idling, open the ball valve just enough to lean the engine so that your EGT is 500°. The only time the ball valve should be closed is between the time when you pull out of staging until you enter the return road.

When racing with a mechanical fuel injection system, such as a toilet, you simply close the fuel shut off enough so that your idling EGT is 500°.
According to both Valvoline and Lucas, do not use synthetic oil if you race with methanol. They both recommend 20W-50 petroleum based racing oil and they both also recommend for the oil to be changed every 30 runs as a maximum. Please see my tech article below dated April 2nd regarding vacuum pumps with alcohol motors.

7.) Methanol burns a little slower than gasoline which means that a little more advance timing is needed for optimum performance. Start out on the rich side with less advance. Sneak up on it until the car slows down, then back up slightly. Each motor is different. Some smaller cubic inch small blocks can run 38-40°, bigger cubic inch small blocks and big blocks 34-36° and blown or turbo charged cars in the 30-32° range. There are a lot of variables such as compression, heads etc.

8.) Methanol as a fuel, responds very well to compression. 14.0:1 - 17.0:1 vs 12.5 - 13.0 on gas.

9) Methanol requires colder plugs. Typically two steps colder than what you would run on gas. My small block uses a NGK BP-9 series plug.

10.) To read spark plugs when using methanol, a proper tune up will show heat discoloration three threads down from top of the electrode end of the plug. You should also see the heat mark on the ground strap just past the top of the bend and a slight coloring of the porcelain on the electrode side near the tip.

11.) A dead cold motor will not start on Methanol. Don't even try it as you will kill a starter in the process. You must prime the motor with gasoline. Ron's Fuel Systems makes a primer kit that contains a 1 quart fuel bottle, a small Purolator fuel pump, hose with fittings and a push button for your dash. The kit also includes a jet to install in your intake but for my car I opted to use an Edlebrock # 70063 nitrous spray bar so that when you prime the motor the fuel is atomized. You just need to cap one end of the spay bar. Once the motor starts and runs, the latent heat from the block will allow the motor to then restart without having to re-prime it.

12.) Caution...prolonged breathing of methanol fumes or prolonged exposure to the skin can cause blindness. Methanol burns with a clear ever so slightly blue flame that is very hard to see. Handle methanol with caution and common sense just like you would with gasoline. Happy racing.............

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Ok I tried an experiment to do. I rode hard to the gas station on reserve and was easily able to see a certain speed down a particular straight before I have to brake. This is conservative breaking but going up to that hard on the gas with late changes. Afterward the bike was mechanically noisy and complaining about being thrashed.

I then went to a local retailer and purchases a fuel additive and filled up with higher octane fuel and added the additive. After ridding for about 5 miles, I went back and tried again, remembering my breaking points, and do forget this is with a FULL tank of fuel.
WOW..greater midrange, greater top end, higher speeds (with ease), I was 8 MPH up perhaps more, and the bike was still running quiet and smooth after a thrashing. It still is.

My compression has always been high. I think at some point my head was skimmed by someone. Perhaps.

I am pretty sure the bike runs cooler and tolerates the timing advance better, it is definately faster (not quite a dyno, but 8mph is obvious)..it is most definately quieter!

I need to do more research, into mixtures and perhaps why it runs so much better on higher octane gas (now about 100RON). Its possible something else is not quite right in the setup and the high octane fuel is lessening that error?

I'll contant a well known local 4 stroke tuner and get his opinion and be sure to tell you guys what he said Smile

Joseph · Full Member Joined: May 22, 2007 Posts: 767 Location: NY

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then went to a local retailer and purchases a fuel additive

[quote]
What additive and how much was put in the tank for this test run?

xs1961

mmm. I put 99 in again day before yesterday & it did run better,dont understand it - unless the warm weather has something to do with it ?

dps-rider · Full Member Joined: Aug 25, 2007 Posts: 100

Humidity makes a big difference. More humidity = lower octane requirement.

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

did nearly 200 miles to day.

Running so well, so quiet, so much cooler and its been a bright day.
Saw an easy 90mph at one point, it was doing it, and I was holding it back!, ie.. not flat out!..

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