What gas octane should I use in a 2007 FJR

[warsw]

Jestal,For once we are on the same page. I agree with ever word. I think there is hope after all. :lol:

Truely scary...... Are you SURE you read my post carefully? Not ONE thing to disagree on?

This is scary. I could not find one thing to disagree on. I couldn't have said it better myself. Fact is I couldn't have said it as well. My hat goes off to you.

Oops........I found something. You misspelled "likely" fifth paragraph last line.

 

[v65]

or any of the other things the internet experts blather about

errr, guilty I guess :blush:

The FJR has no knock sensor

Oops, was running with another post there, still haven't finished reading the FSM yet.

Within all practical reason premium and regular fuels burn at the same rate and contain the same energy content. The idea that an engine is "designed for regular" and will not make as much power on premium is an old wives tale at best. There are some highly specialized racing engines that will run correctly on only the exact fuel they were designed for but general use automotive/motorcycle engines are not in this category. Similarily, yes, if the engine runs fine on regular with no detonation then you will not get any more power by using premium. The regular fuel requirement by Yamaha indicates the FJR engine is pretty tolerant of fuel quality and is not likey to barf using regular fuel.

Jestal,

That's related to the point I didn't hash out earlier. Since I seem to be suffering from some misgivings here let me run a couple of more ideas by you:

1) When lead was removed from fuels there was a period of time when higher octane fuels could not be found at the pump. I was still pre drivers license at the stage, but I remember the hot rod magazines constantly complaining. At that time there were not any performance cars in the modern sense of the word. Two things happened - a cheap way of introducing octane into unleaded fuels was introduced, and combustion chambers were redesigned to eliminate hotspots, so that higher compression engines could be run on 87 octane. And a decade later 300hp engines were back (sure there were other contributing factors ).

2) I suspect I may really get an ear full on this one. Octane is a measure of the fuels ability to resist pre-ignition. Does that not mean that higher octane fuels are harder for the ignition system to ignite? My thinking was that higher octane fuels may not be completely burned on an ignition system designed (there's that word again, seems not to be popular in this thread) to ignite a lower octane fuel.

In this case designed means a system with enough juice to properly ignite 87 octane fuel, not 93. If I understand engineering anything would be overkill. Properly means to fully burn the air/fuel mixture in the chamber. Fully means ...

So are you saying that the FJR's ignition system has enough spark for this not to be a worry, that all modern ignition systems have enough spark for this not to be a worry, or am I misinformed?

 

[v65]

Another question, this time about the knocking. I would think that the engine would have enough of a load at 30mph in third gear under acceleration to hear any knocking, and that at this speed you would be able to hear it. Can you clarify what you mean by you wouldn't count on being able to hear it? Is it possible for an engine to have a "small" detonation problem that is inaudible?

BTW, interesting to hear that modern knock sensors react before the knock is audible. Not completely sure that is a good thing.

 

[sprint_st]

Jestal,That's related to the point I didn't hash out earlier. Since I seem to be suffering from some misgivings here let me run a couple of more ideas by you:

1) When lead was removed from fuels there was a period of time when higher octane fuels could not be found at the pump. I was still pre drivers license at the stage, but I remember the hot rod magazines constantly complaining. At that time there were not any performance cars in the modern sense of the word. Two things happened - a cheap way of introducing octane into unleaded fuels was introduced, and combustion chambers were redesigned to eliminate hotspots, so that higher compression engines could be run on 87 octane. And a decade later 300hp engines were back (sure there were other contributing factors ).

2) I suspect I may really get an ear full on this one. Octane is a measure of the fuels ability to resist pre-ignition. Does that not mean that higher octane fuels are harder for the ignition system to ignite? My thinking was that higher octane fuels may not be completely burned on an ignition system designed (there's that word again, seems not to be popular in this thread) to ignite a lower octane fuel.

In this case designed means a system with enough juice to properly ignite 87 octane fuel, not 93. If I understand engineering anything would be overkill. Properly means to fully burn the air/fuel mixture in the chamber. Fully means ...

So are you saying that the FJR's ignition system has enough spark for this not to be a worry, that all modern ignition systems have enough spark for this not to be a worry, or am I misinformed?

On your #1 item, I was definitely around at that time and premium unleaded was NOT hard to find, although we started to get to embargoes where all gas was hard to find for short periods of time. There were lots of "muscle cars" running around then and they had problems with gas and ping from purchase because they always played with timing and other stuff to make them faster. There were also additive to include tetraethyl lead available to add to the gas. There were lots of things going on in those days to include emission controls. I spent those years ripping off stock carbs and ignitions and replacing them with after market Edlebrock, Holly, etc components that were stone age which would make the car run right, because they just would not with all the factory emission crap that were just bandaid fixes to comply with the EPA.

On #2, I hear what Jestal says about regular and premium being about the same rate but I would like to see his data on that. Detonation is all about burn rate. The octane rating has very little to do with the molecule, octane. Octane is not octane, it may be 2-2-4 trimethylpentane or even a mix of non-isomers that when put in a special one cylinder engine provide a specified anti-knock rating. Avgas used to use toluene to give it 100 octane and there are other examples of various mixes, mainly containing some base pentane. Also, the octane rating has nothing to do with pre-ignition because pre-ignition is a totally separate condition than detonation. Detonation is a condition when gas burns so fast it explodes. The octane rating engine provides a well defined environment to define exactly what one gas's octane rating is compared to any other. How that could be done and have premium of a higher octane rating and regular at lower and both burn at the same rate does not make sense to me.

Something I overlooked was the discussion on "enough spark". All modern bikes probably have enough spark to light kerosene. It's the spark timing that matters and to me is a red herring in this discussion.

 

[v65]

On your #1 item, I was definitely around at that time and premium unleaded was NOT hard to find

OK, remembering something incorrectly there.

Detonation is a condition when gas burns so fast it explodes.

I thought detonation was caused by heat in the cylinder igniting the air fuel mixture, causing two (or more) separate ignitions in the chamber. Hence the need to redesign the cylinder/piston domes to eliminate these hot spots.

EDIT: Does this guy know what he is talking about?

 

[jestal]

See...you give people too much detail.... If someone doesn't like to know WHY they only need to run 87 octane they can stop reading back then.

Keep in mind that detonation and preignition are two TOTALLY different phenomenon. Detonation happens when the end gas in the chamber spontaneously combusts....this happens AFTER the normal spark event has ignited the mixture. Preignition means the mixture ignited somehow BEFORE the spark sparked. Totally different issues. Related in a way but totally different. Increased octane ratings will NOT prevent preignition.

There are a lot of ways of increasing the octane rating of the fuel. Even alcohol (methanol and ethanol) have an "octane" rating despite the fact that they contain no gasoline or octane or 2-2-4 trimethylpentane.

Octane rating, simply stated, is the fuel's ability to resist detonation. Period. Nothing to do with burn rate, heat energy, difficulty in lighting, etc.

Some premiums have the octane rating increased by adding alcohols or other oxigenates which is where the discussion of higher octane fuel burn rates gets a bit sticky....alcohol does burn slower.

Chambers never really had "hot spots." Easy explaination for HotRod magazine to come up with but that wasn't the problem. Chamber design, turbulence, swirl, tumble, incylinder mixture motion, squish bands to add turbulence are the main things that changed that allow later model engines to run higher compression on lower octane fuel. The chambers still run at the 210 F that the thermostat regulates at.

 

[ShinyPartsUp]

Jestal,

I gotta say reading your technical posts is like reading Kevin Cameron. Really enjoyable and mostly understandable, even for a hack like me. You're on my list of people I'd love to buy dinner and a drink or two and just listen.

Thanks for posts like these.

See...you give people too much detail.... If someone doesn't like to know WHY they only need to run 87 octane they can stop reading back then.

Keep in mind that detonation and preignition are two TOTALLY different phenomenon. Detonation happens when the end gas in the chamber spontaneously combusts....this happens AFTER the normal spark event has ignited the mixture. Preignition means the mixture ignited somehow BEFORE the spark sparked. Totally different issues. Related in a way but totally different. Increased octane ratings will NOT prevent preignition.

There are a lot of ways of increasing the octane rating of the fuel. Even alcohol (methanol and ethanol) have an "octane" rating despite the fact that they contain no gasoline or octane or 2-2-4 trimethylpentane.

Octane rating, simply stated, is the fuel's ability to resist detonation. Period. Nothing to do with burn rate, heat energy, difficulty in lighting, etc.

Some premiums have the octane rating increased by adding alcohols or other oxigenates which is where the discussion of higher octane fuel burn rates gets a bit sticky....alcohol does burn slower.

Chambers never really had "hot spots." Easy explaination for HotRod magazine to come up with but that wasn't the problem. Chamber design, turbulence, swirl, tumble, incylinder mixture motion, squish bands to add turbulence are the main things that changed that allow later model engines to run higher compression on lower octane fuel. The chambers still run at the 210 F that the thermostat regulates at.

 

[FJRottie]

The several oils extracted from the olive fruit can be classified as:

Virgin means the oil was produced by the use of physical means and no chemical treatment. The term virgin oil referring to production is different from Virgin Oil on a retail label (see next section).

Refined means that the oil has been chemically treated to neutralize strong tastes (characterized as defects) and neutralize the acid content (free fatty acids). Refined oil is commonly regarded as lower quality than virgin oil; the retail labels extra-virgin olive oil and virgin olive oil cannot contain any refined oil.

Pomace olive oil means oil extracted from the pomace using chemical solvents—mostly hexane—and by heat.

Quantitative analysis can determine the oil's acidity, defined as the percent, measured by weight, of free oleic acid in it.

This is a measure of the oil's chemical degradation; as the oil degrades, more fatty acids get free from the glycerides, increasing the level of free acidity. Another measure of the oil's chemical degradation is the peroxide level, which measures the degree to which the oil is oxidized (rancid).

In order to classify olive oil by taste, it is subjectively judged by a panel of professional tasters in a blind taste test. This is also called its organoleptic quality.

Retail grades in IOOC member nations Since IOOC standards are complex, the labels in stores (except in the U.S.) clearly show an oil's grade:

Extra-virgin olive oil comes from the first pressing of the olives, contains no more than 0.8% acidity, and is judged to have a superior taste. There can be no refined oil in extra-virgin olive oil.

Virgin olive oil has an acidity less than 2%, and judged to have a good taste. There can be no refined oil in virgin olive oil.

Olive oil is a blend of virgin oil and refined virgin oil, containing at most 1% acidity. It commonly lacks a strong flavor.

Olive-pomace oil is a blend of refined pomace olive oil and possibly some virgin oil. It is fit for consumption, but it may not be called olive oil.

Olive-pomace oil is rarely found in a grocery store; it is often used for certain kinds of cooking in restaurants.

Lampante oil is olive oil not used for consumption; lampante comes from olive oil's ancient use as fuel in oil-burning lamps. Lampante oil is mostly used in the industrial market.

 

[jestal]

What about whale oil.....????????????????????????

 

[sprint_st]

Detonation is a condition when gas burns so fast it explodes.

I thought detonation was caused by heat in the cylinder igniting the air fuel mixture, causing two (or more) separate ignitions in the chamber. Hence the need to redesign the cylinder/piston domes to eliminate these hot spots.

EDIT: Does this guy know what he is talking about?

I think what you believe is detonation is closer to what is known as pre-ignition. Pre-ignition does have hot spots and even, I believe, causes dieseling in severe cases. Ever have a car run after you turn off the key, that's dieseling. Not what we are discussing at all. As far as what that guy knows or doesn't know, I don't feel like reading another one of these guys perspectives on things. There are plenty of good articles on what detonation is and what octane is. Jestal and I may go into semantics or the fine print but I do not believe we differ all that much. To sum up my point of view, Yamaha says regular is OK, so that is what I use. Jestal's point of view (please correct me if my observations are incorrect) is in his experience premium is better gas because it has a much better additive package and won't hurt anything.

 

[v65]

Since I seem to be suffering from the misinformation malady, I still have lots of questions here. It might be easier to read a text on the subject. As a youth I found a book of about 300 pages that went into the "basics" of engine design, but at a reasonably deep level (for a 13 year old). I would be interested in a similar modern book that covers the intake and combustion process. Topics I would be interested in reading about include:

1) Induction design - use of plenums, swirl (the big buzzword), intake velocity versus volume, and other design factors and how these affect the combustion process.

2) The combustion process itself. How does piston/chamber design effect the combustion process, what role does the quench area play, etc.

3) Lots of topics I am unaware of or have forgotten about.

Any suggestions on a book that would cover this material (and more) at a depth appropriate for someone that likes to read technical books (in other words at the level Jestal generally uses)?

If someone doesn't like to know WHY they only need to run 87 octane they can stop reading back then.

Pete left a long time ago, he's asking about oil now :blink:

 

[FJRMGM]

the world, as we currently know it, is surely about to end.

"Jestal,

For once we are on the same page. I agree with ever word. I think there is hope after all. "

 

[TruWrecks]

A fuel injected engine won't diesel unless it's a diesel. Carbs can diesel because the vacuum is pulling fuel into the firing chamber.

Back to a simple answer. 87 or higher is ideal.

BTW Just because you didn't hear it knock, doesn't mean it didn't. It just didn't knock hard enough.

 

[Rogue]

 

[twowheelnut]

Teach a man to fish...

 

[Bounce]

BTW, since i've not seen it yet. Welcome back Jestal. Glad to see you posting again.

 

[conwest]

Well...at the risk of venturing onto hallowed ground here, I for one must take issue with the following "Jestalism": Increased octane ratings will NOT prevent preignition.

Exuse me? This is a blatant contradiction of every fuel industry analysis I`ve ever read/written. Nevermind me...just ask the guy who had a "knock" condition (assuming all the other pertinent parameters are in spec), who was advised to burn higher octane fuel and then, engine knock had disappeared. Simply put, in most cases engine knock is caused by preignition. The cure: higher octane. But then, I thought that was common knowledge by now. What gives Jestal?!

 

[charismaticmegafauna]

I'm in no way attempting to speak for 'jestal' -- but, pre-ignition and detonation are two different things. Octane rating is for helping detonation problems caused by too much spark advance for the the combination of fuel mix/combustion chamber/compression/temp/and (probably?) a myriad of other things. It's an event that happens after ignition by the spark plug and is/has been somewhat 'normal' -- called "pinking" (by the Brits) and has often been suggested as being OK in mild cases. Historically, it's been a good way to set ignition timing -- on-set of spark knock -- and you could adjust it at the steering wheel on a Model A Ford.

Pre-ignition, however, is self-ignition before the spark event and can be disastrous to an engine by trying to compress an already expanding/exploding mixture. I doubt if octane can help much -- this severe condition? FWIW -- my $.02 :huh:

 

[conwest]

I'm in no way attempting to speak for 'jestal' -- but, pre-ignition and detonation are two different things. Octane rating is for helping detonation problems caused by too much spark advance for the the combination of fuel mix/combustion chamber/compression/temp/and (probably?) a myriad of other things. It's an event that happens after ignition by the spark plug and is/has been somewhat 'normal' -- called "pinking" (by the Brits) and has often been suggested as being OK in mild cases. Historically, it's been a good way to set ignition timing -- on-set of spark knock -- and you could adjust it at the steering wheel on a Model A Ford.Pre-ignition, however, is self-ignition before the spark event and can be disastrous to an engine by trying to compress an already expanding/exploding mixture. I doubt if octane can help much -- this severe condition? FWIW -- my $.02 :huh:

ahh, say what? Surely, yer not falling for this. Me thinks something is happening here that is not all what appears. I believe somebody (Jestal perhaps?), is attempting to screw with our minds. Nice try. I for one am not taken in by this so called Jestal`s presence. Fraud I say...off with his head! :assassin:

 

[v65]

I think we still have some confusion (at least I do) on pre-ignition. The word before is not well-defined in this discussion in my opinion.

Before definition 1: Ignition will occur at time t0. Somewhere in the combustion chamber the air/fuel mixture auto ignites at a time before t0 (in the same cobustion cycle).

Before definition 2 Ignition occurs (from the plug as it should). At time t_P the flame from this ignition should reach point P in the combustion chamber, but before that can happen auto ignition occurs at P. In other words auto-ignition could occur in the combustion chamber at one point at the same time as ignition from the spark plug.

I have been using definition 2, but with the wording some of you are using it sounds like you are using definition 1.