What Gas do you Put In..?

[Anonymous]

Here's another monkeywrench... Since the gov't has started to reduce the amount of MTBA in fuel, do we, or will we see an increase in alcohol/ethanol mixed fuels? Personally, I use 87 octane in my GK, but I'm concerned on whether we're gonna run into problems since ethanol is supposed to cause problems by running hotter.

[Anonymous]

That's a damn good question, one that some of us locally have talked about. My understanding is that the stuff will play havoc with our aluminum carburetors. Maybe someone can enlighten us here and develop this further.

Nick

[Anonymous]

I'll have to do a little investigation on this I think.

A thought off the top of my head though. Most carburetors are aluminum - autos, trucks, motorcycles, etc. Also fuel pumps, regulators, etc. If we are effected, then everyone is. I have doubts that they would screw up the entire country. Could be wrong though.

[lhanscom]

Aluminum and Contact with Ethanol


09.30.02 - Should ethanol be used with aluminum? The answer is not as simple as you may think. Ethanol experts agree that low amounts of ethanol (10% or less) may maintain contact with aluminum but higher amounts (70 to 85%) should not.

Ethanol, in its pure form, is an alcohol and therefore is corrosive with certain metals. High amounts of ethanol in fuel will corrode any aluminum in which it has contact. The corrosion will in turn contaminate
transportation fuel.

It has been brought to NEVC?s attention that some confusion has developed
regarding two recent publications supported by ethanol experts: The Fuel Ethanol Guideline published by RFA states that ethanol is compatible with aluminum and the Handbook for Handling, Storing, and Dispensing E85 published by NREL, DOE and NEVC states the opposite. Both publications are correct. The clarification between the two documents is to state that RFA focuses on low blends of ethanol at 10% or less and the NEVC focuses on
higher blends of ethanol.

Agreement was made between RFA Technical Consultant, Bob Reynolds, and NEVC Executive Director, Phil Lampert, that reference additions should be added
to the RFA document. These changes supported by SAE Technical Paper 940764; AAMA "Fuel Ethanol Compatibility Standards and Dispensing Equipment List for E85 Fueled Vehicles", August 10, 1995 GM R&D Paper, PR-448-March 1994 will
be included in the final issuance of the Technical Manual.

In conclusion, when using low level blends of ethanol such as E10, it is very satisfactory to store and dispense the product with aluminum equipment.
When using high-level blends of ethanol such as E85, the use of aluminum
should be avoided.

[AOD]

Ethanol is okay.

its mix in gasoline is controlled by the EPA regarding which area of the country you live in. for example, Chicago is required to have Ethanol in its fuel. Every gas you buy in Chicago has Ethanol in it, UP TO 10%.

gasoline makers like this because Ethanol is more volatile then gasoline...it raises the octane rating on fuels, so they can save money by starting with a lower grade fuel ~83 octane, and adding 10% ethanol to increase octane rating. ethanol is also man made, and cheaper. ethanol is good in moderation because it reduces the emmissions from our engines.

since i'm near Chicago, in the corn producing area's, farmers want people to use ethanol fuels. i have run my bike on the Chicago fuels with no problems...i dont forsee any problems for you guys either.

~Adam

[Anonymous]

Good information - thanks.

[redliner1973]

brand should not matter on our bikes. I go to Sheetz, Sunoco, Amoco, Shell, whichever is handy at the time. The mighty GK runs the same no matter what. Same with the four 850's that preceded it.

Fix your bike so you can run on the cheap stuff.

Cheapskate Nick

Well, Nick is right on this one. the GS is designed for 87 Octane. If you need a higher octane it is because there is something wrong. Usually carbon build up, or oil getting past the valve guides ( oil will really make an engine ping). Most gas is purchased from one major supplier in the area and distributed among several distributers in a given local. I have rode with a buddy who delivered fuel. He stopped at major competitors stations, dropped off, then goes to the local maji-mart and drops there. refills the truck and starts all over. A minute amount of carbon can raise the compression enough to raise octane requirements. it does not take much. this is why they say "may need higher requirement after 20K miles". the use of premium fuel in an engine requiring only regular will only accelerate the carbon build up. Whilst the BTU's of both the fuels are basically the same, gasoline burns slower as compression is lowered. In other words, the higher the compression, the faster it burns. hence the reason 87 will knock in a high compression motor. in a lower compression engine, the premium burns slower, and the piston moves alot of it out the pipe before combustion is actually complete. incomplete combustion = carbon build-up. it is a vicious cycle. If you take an engine that runs good on 87, and run premium in it, and put the engine on a dyno, it will have LESS hp than the 87. also, Detergency is the SAME FOR ALL GRADES of fuel. this is a Gov. mandate. 92 does NOT have more detergent than 87.
Now to the Ethanol issue. 1st off, ethanol in pump gas is not sufficient enough to be concerned with aluminum corrosion as much as it is to the rubber parts in the carbs. Bikes built today do not have this problem, but if your bikes carbs have not been resealed with todays gaskets, try and avoid it. Also, ethanol in itself does not make an engine run hotter. Ethanol is thicker than gasoline, and stuffing it in the same size jet causes a leaner condition. this in turn raises heating of the engine. BUT, ethanol runs Cooler during a burn than gasoline. so temps are equalised. Now, you have to take in consideration that ethanol also has less BTU's than gas. So more throttle is needed to produce the same amount of power. More throttle = more heat = hotter running. this also explains why alot of people complain that their mileage goes down slightly on ethanol, they actually have to give it more throttle hence giving the engine the impression it is working harder, therefore consuming more fuel. I hope this helps.... :twisted:

[dpep]

May as well throw my .02 on this. My original 850 owners manual, "Use only unleaded or low-lead type gasolline of at least 85-95 pump octane (R+M/2 method) or 89 octane or higher rated by the Research method".

I noticed a few years ago that in Florida in the summer in the heat of the afternoon out on I-95 with 2 up on my 850 I got pinging while trying to accelerate around intersate speed limit traffic. That was with premium fuel. The engine was high mileage but had an oil cooler. I know from top end work done around the time that there was minimal carbon build up. Heat and compression are both factors in preignition.

I understand that these might be considered extreme conditions, but my phlosophy has always been to provide for the worst case just in case. I use synthetic oil for the same reason.

I had a complete rebuild about 10,000 ago. Now that it is broken in I may try a couple of tanks of 87 during August to see if it behaves differently.

[Anonymous]

Hey, that 850 on your avatar looks great! I like that yellow.

I had an 80 GS850GT before the GK, my fourth and last 850. Great bikes they all were.

Nick

[dpep]

Hey, that 850 on your avatar looks great! I like that yellow.

Nick

Thanks, Nick. The compliment means a lot coming from the dean of the the shaft-drive school. The color is Corvette yellow. I agree with you about the greatness of the 850. I think it is only a 6th gear away from being the perfect all-around street motorcycle. Well, maybe a little more juice would be good too.

[Anonymous]

What you say is true. The 850 always needed that 6th gear and/or a bit more "oomph".

That's why I went for the GS1100GK four years ago. Best move I've ever made is buying that thing. It was all the virtues (and boy, there are many such virtues!) of the 850, with considerably more kick and longer legs.

Send more pictures of that gorgeous yellow to Dan Bard, the GS Resources editor in charge of the Gallery. I'm sure he'd like to upload them, since he himself rides a yellow Gold Wing 1800.

Nick

[focus frenzy]

close, but not quite Tim.
carbon build up will, over time raise the compression enough to be a problem, but with bikes that get wrung out on a semi regular basis carbon build up is not a problem.
Carbon causes detonation more from its causing hot spots in the combustion chamber,triggering pre-ignition.

taking a bike and with the engine warmed up, you run it up through a couple gears at full throttle and you will "blow" out most carbon build up.

Ethanol is a alcohol and it is not "thick" it is pretty thin stuff so it doesn't "stuff" in the jets.
a byproduct of burning ethanol is a small amount of oxygen (that is part of the reason why alcohol burns so hot) this is what makes a normal carburetor engine run a bit leaner, modern fuel injected automotive engines compensate by adding a bit more fuel, hence the slightly lower fuel mileage. my bike gets the same mileage regardless of the type of fuel I use, but I have to use premium do to my higher compression.

the design of the combustion chamber has allot to do with detonation, unfortunately our bikes don't have a very good combustion chamber design.

[Anonymous]

There is lots of authoritative information available on this subject. Follow your owners manual instructions as to appropriate fuel. Thereafter, there is no reason to buy premium gases unless you are suffering serious and persisent knock. Premium gases do nothing else except control knock.

High octane gases have NO EXTRA POTENTIAL ENERGY, and can not provide a power boost.

Despite what some owners perceive as far as power and fuel mileage go, proper control tests results show otherwise.

Premium gases clean the engine no better than 87 octane gases, and the oil companies have been successfully sued by the US Federal Trade Commission amongst others for saying otherwise. The results and rulings are available online ...I took the time to read them. This forced truth in advertising is why the ads I hear now say: "No gasoline cleans better than [insert company name here] ultra-premium." How impressive! Our very expensive premium gas is no worse than other gases!

I have to use 94 Octane gas in the twin-cam HD I ride (as specified in the owners manual), and it still knocks under load on very hot days in stop and go traffic.
That is because it has a huge cylinder volume (725cc) and runs at low rpm. Four-cylinder Japanese bikes have small cylinder volumes and run at higher rpm's, and are naturally resistant to knock, even at moderately high compression ratios. The HD knock is the logical result of trying to wring 70hp from an antiquated engine design.

Don't waste your money on premium fuels. They actually cause air-cooled bikes to run hotter and less efficiently. True!

In my experience, most knock in mildly tuned engines like ours will go away with judicious use of the transmission. Keep the revs up under load!

[redliner1973]

close, but not quite Tim.
carbon build up will, over time raise the compression enough to be a problem, but with bikes that get wrung out on a semi regular basis carbon build up is not a problem.
Carbon causes detonation more from its causing hot spots in the combustion chamber,triggering pre-ignition.

taking a bike and with the engine warmed up, you run it up through a couple gears at full throttle and you will "blow" out most carbon build up.

Ethanol is a alcohol and it is not "thick" it is pretty thin stuff so it doesn't "stuff" in the jets.
a byproduct of burning ethanol is a small amount of oxygen (that is part of the reason why alcohol burns so hot) this is what makes a normal carburetor engine run a bit leaner, modern fuel injected automotive engines compensate by adding a bit more fuel, hence the slightly lower fuel mileage. my bike gets the same mileage regardless of the type of fuel I use, but I have to use premium do to my higher compression.

the design of the combustion chamber has allot to do with detonation, unfortunately our bikes don't have a very good combustion chamber design.

I have to disagree with you on this one, According to the university of Wisconsin, Madison, here are some of the following on properties of Ethanol:

Ethanol is lighter than water, if released in to water it tends to remain near the water's surface

Ethanol containing Gasoline is DENSER than unblended gasoline

When burned, Ethanol releases LESS HEAT than gasoline. 1 1/2 gallons of ethanol have approximately the same combustion properties as 1 gallon of gasoline

Ehanol has a higher ignition temp than gasoline 850F vs. 495F

At 110, Ethanol has an Octane rating simular to MTBE's. thus, when added to gasoline, Ethanol increases the Octane rating.

(http://uttu.engr.wisc.edu/UT14n4.pdf)

Now, #1 is pertinant to water in fuel only.
#2 supports the thicker fluid in same size jet = leaner condition theory.
#3 the LESS HEAT means more throttle opening for same power, and Cooler flame. ( offset, of course, by the higher throttle opening)
#4 Ethanols higher ignition temps support the lower BTU output = less power.

As for the Carbon issue, yes, I will agree 100% that Combustion design makes a world of difference, but remove the head of any engine with some miles on it, that has been 'blown out' on occasion, and you will still see a significant amount of built-up carbon on top of the piston. I have NEVER torn down an engine short of brand new that did not have some deposits on the piston crowns. this also helps to explain the myriads of 'fuel injector and combustion chamber cleaners' o the market nowadays. Combustion with fossils are just not efficient enough to prevent it. :twisted:

[Anonymous]

If adding ethonal to gasoline give a lower temp, then the thread about powdercoating or otherwise insulating the headers seems to make more sense in that it keeps the exhaust gas heat in the exhaust system. That would appear to help eliminate the cooler spots in the exhaust system restricting the flow.
So, then, if one is running a gas/ethanol mixture one should realize something of a reduction in the loss of power/milage if one insulates the exhaust?
It looks like it ties together, but I may have my head in an anatomically improbable place.

Harrison