Gas premium 93 octane??? that sucks

[crammit442]

In simple terms, the higher octain will control the burn rate of the fuel. basicly slowing it down. A given motor with high compression & agressivly advanced timing reguires a slow burn fuel (high octain) so detonation doesn't take place. if you were to run regular fuel in this type motor, a flash burn would occur & you would surely burn down the motor
the key to building a high output motor is to creat as high a BTU burn output without detonating. a combination of compression, timing advance, squish rate, fuel used, are all key factors. obviously, there is lots more to it. this is just to give you the idea

Jens, Give me the basics of your motor & I'll try to get you a good fuel to use while you are here. as was noted, AVGAS is a good otion for you. it is 100LL & can be purchased at most regional airports

ski ya, Paul

That's kinda correct.:smile: The octane rating does NOT denote the burn RATE of a fuel. It ONLY denotes the fuel's resistance to detonation/pre-ignition. The specific chemical make up of a given fuel will determine the burn rate /energy potential. Fast burning fuels can be very high octane. What we want is a fuel that doesn't burn until we want it to, but then burns very rapidly. High energy potential(BTU's) is also very possible with race fuels. Even in a stock motor a race fuel with characteristics suited for your setup will absolutely produce more power than pump gas. Race gas doesn't necessarily even have very high octane. Also, as somebody said earlier, the octane # on the pump in Euprope is normally the RON where ours is the average of MON and RON. MON is much more important to what we do.:biggthumpup:

Charles

 

[MADMAT]

Can we see some basic rule of thumb? I'm curious too now! I would love to get away with 89 this summer$$!! 81.5 Wiseco, 38's w/carbon tech, Speedwerx Dry, ported cases with non ported cylinders?

 

[Jr.]

Can we see some basic rule of thumb? I'm curious too now! I would love to get away with 89 this summer$$!! 81.5 Wiseco, 38's w/carbon tech, Speedwerx Dry, ported cases with non ported cylinders?

Matt, Just because of the evactuation princible of the dry pipe, run the highest octaine fuel you can get at the pump

Charles, as we both know, there is so much complexity to fuel chemestry & how everything works in a motor, I just used a brief explanation & put it into the terms most can understand. If some are intrested, I would be happy to start a thread on this very subject. as long as it will stay on point & remain informative. You know how it can get?

ski ya, Paul

 

[yamaslut]

yeah... that would be cool... I would like to understand that a little better

 

[MADMAT]

I figured that. 94 it is then!! I just bought a motorless push lawnmower to save gas for ridin!!!:woot:

 

[Frosty]

yeah... that would be cool... I would like to understand that a little better

Yeah, me too. I would love to add more compression... but my biggest concern is detonation. And, not knowing all that much about octane, as it relates to compression and other ski components, I don't want to risk going higher than I'm at now.

 

[PancakePete]

I am lost..... But theres something new.
I just know.... Dont land upside down.. It hurts... :Banane01:

I am going to try some Additives from Klotz soon, Because Jersey gas is getting worse by the minute.
I swear they cut the gas with water... Super is like Regular now. and Regular is like Piss from a night drinking.

 

[douglee25]

There are two easy ways to read or know detonation is occuring.

1. With a spark plug magnifier. Basically what you're looking for are tiny specs that look like pepper on the insulator tip. This comes from tiny pieces of the piston melting because the combustion temperature is too great.

Magnifier

2. Hooking up a knock sensor to the block which will read uncontrolled combustion.

I personally haven't seen either of these items used in the jetski world, nor do I know how applicable they could be either. Using a plug magnifier may prove tough due to the engine being a two stroke. The oil would probably tend to complicate the viewing process. The only possible work around may be a fresh set of plugs and then taking the ski for a wide open pass. Then read the plugs. If it idles and builds up carbon, the read will be no good. Using the knock sensor would require some electrical wiring. It could be programmed to record the number of times it senses detonation, but recording at how great a level (amplitude wise) would be tough. I'm sure it could be done though.

Read this 'how to' on reading spark plugs.

http://en.wikibooks.org/wiki/Reading_spark_plugs_for_racing

Doug

 

[Jr.]

There are two easy ways to read or know detonation is occuring.

1. With a spark plug magnifier. Basically what you're looking for are tiny specs that look like pepper on the insulator tip. This comes from tiny pieces of the piston melting because the combustion temperature is too great.

Magnifier

2. Hooking up a knock sensor to the block which will read uncontrolled combustion.

I personally haven't seen either of these items used in the jetski world, nor do I know how applicable they could be either. Using a plug magnifier may prove tough due to the engine being a two stroke. The oil would probably tend to complicate the viewing process. The only possible work around may be a fresh set of plugs and then taking the ski for a wide open pass. Then read the plugs. If it idles and builds up carbon, the read will be no good. Using the knock sensor would require some electrical wiring. It could be programmed to record the number of times it senses detonation, but recording at how great a level (amplitude wise) would be tough. I'm sure it could be done though.

Read this 'how to' on reading spark plugs.

http://en.wikibooks.org/wiki/Reading_spark_plugs_for_racing

Doug

Doug, Those tools work great in the 4 stroke world, but in the high perf 2 stroke, things happen pretty fast. a second or two & it's all over. irereversable damage has happened. I wish it was a easier learning curve

I'll compile some info & start a fuel thread. Give me a day or two, as you can guess I'm very swamped at the moment.

ski ya, Paul

 

[Prem1x]

The numbers may not be the same. In the US the num on the pump is an average of research and motor octane. I'd think if 93 is the lowest in europe they are likely using a different system.

I'm pretty sure Europe's octane calcaaulation is different from ours.

 

[Waste Land]

Magoo....

Whats the deal with the dry pipe needing higher octane on stock motor then say a Bpipe? I thought the primary idea of high octane was to control premature explosion of the gas under pressure. I had the idea octane was purely a decision of compression psi.

I have a good idea on how pipes works and such, but dont understand why a dry pipe would call for mroe octane.

Thanks

 

[#ZERO]

In the United States, pump octane is an average of 2 ratings, Research Octane Number (RON) and Motor Octane Number (MON). If you look at any gas pump in the United States, you will see a yellow sticker that says "octane by R + M / 2" That is the basic formula for an average. These 2 numbers mean different things. The Motor Octane Test employs a higher temperature and RPM and hence is probably a better indicator for today's engines.

In Europe, they only report the RON. You may hear people discussing that in Europe, the octane is higher. Well, that is not exactly true. You see, in Europe, you might find 98 octane at a local gas station. (wow 98, highest we have here is 94). Well, that 98 is equivalent to 94 here in the States. The Research Octane Number is always higher than Motor Octane Number.

The octane value of a fuel can be varied by several different processes. It can be refined to that value (usually more costly) or enhanced with different additives. Different people will argue which method is better.

Of course the Research octane test gives a higher number and that's why the European manufacturers quote it (RON)

http://www.btinternet.com/~madmole/Reference/RONMONPON.html

 

[Matt_E]

I thought I explained all that on page one. :biggrin:

 

[JensNonsens]

I thought I explained all that on page one. :biggrin:

ok, schaub sagte er hat den motor auf 100 octan eingestellt, das entspricht aber nicth wirklich 93 octan hier in den usa oder?? er sagte mir ich solle av gas fahren. wie jrmagoos auch.

sorry for the german....

 

[#ZERO]

I thought I explained all that on page one. :biggrin:

Yes you were right, I just further expained it in German.

In den Vereinigten Staaten ist Pumpe Oktan ein Durchschnitt von 2 Bewertungen, erforscht Oktan-Zahl (RON) und Bewegungsoktan-Zahl (MON). Wenn Sie irgendeine Gaspumpe in den Vereinigten Staaten betrachten, sehen Sie einen gelben Aufkleber, der "Oktan durch R + M/2" sagt, das die grundlegende Formel für einen Durchschnitt ist. Diese 2 Zahlen bedeuten unterschiedliche Sachen. Der Bewegungsoktan-Test setzt eine höhere Temperatur ein und U/min und ist folglich vermutlich eine bessere Anzeige für heutige Maschinen. In Europa berichten sie nur über das RON. Sie können Leute hören, die in Europa zu besprechen, das Oktan sind höher. Gut ist das nicht genau zutreffend. Sie sehen, in Europa, Sie konnten Oktan 98 an einer lokalen Tankstelle (das Wimmern 98 finden, am höchsten haben wir sind hier 94). Gut diese ist 98 bis 94 hier in den Zuständen gleichwertig. Die Forschung Oktan-Zahl ist immer höher als Bewegungsoktan-Zahl. Der Oktanwert eines Kraftstoffs kann durch einige unterschiedliche Prozesse verändert werden. Er kann zu diesem Wert verfeinert werden (normalerweise teurer) oder mit unterschiedlichen Zusätzen erhöht werden. Unterschiedliche Leute argumentieren, welche Methode besser ist. Selbstverständlich gibt der Forschung Oktantest eine höhere Zahl und der ist, warum die europäischen Hersteller es veranschlagen (RON) und wenn Sie zu wenig Oktan auf einer hohen Kompression Maschine benutzen, nimmt der Motor eine Scheiße.

 

[Matt_E]

Uh yeah, nice "Babelfish" german there. Jens, I agree...100 RON is nowhere near 93 MON, so run AVGas.

Smells nicer anyway. NICE MOTOR!!!

 

[IceRocket1286]

i have 110 on the corner. its red, and my vette likes it

 

[IceRocket1286]

Yes you were right, I just further expained it in German.

In den Vereinigten Staaten ist Pumpe Oktan ein Durchschnitt von 2 Bewertungen, erforscht Oktan-Zahl (RON) und Bewegungsoktan-Zahl (MON). Wenn Sie irgendeine Gaspumpe in den Vereinigten Staaten betrachten, sehen Sie einen gelben Aufkleber, der "Oktan durch R + M/2" sagt, das die grundlegende Formel für einen Durchschnitt ist. Diese 2 Zahlen bedeuten unterschiedliche Sachen. Der Bewegungsoktan-Test setzt eine höhere Temperatur ein und U/min und ist folglich vermutlich eine bessere Anzeige für heutige Maschinen. In Europa berichten sie nur über das RON. Sie können Leute hören, die in Europa zu besprechen, das Oktan sind höher. Gut ist das nicht genau zutreffend. Sie sehen, in Europa, Sie konnten Oktan 98 an einer lokalen Tankstelle (das Wimmern 98 finden, am höchsten haben wir sind hier 94). Gut diese ist 98 bis 94 hier in den Zuständen gleichwertig. Die Forschung Oktan-Zahl ist immer höher als Bewegungsoktan-Zahl. Der Oktanwert eines Kraftstoffs kann durch einige unterschiedliche Prozesse verändert werden. Er kann zu diesem Wert verfeinert werden (normalerweise teurer) oder mit unterschiedlichen Zusätzen erhöht werden. Unterschiedliche Leute argumentieren, welche Methode besser ist. Selbstverständlich gibt der Forschung Oktantest eine höhere Zahl und der ist, warum die europäischen Hersteller es veranschlagen (RON) und wenn Sie zu wenig Oktan auf einer hohen Kompression Maschine benutzen, nimmt der Motor eine Scheiße.

please, no more dumb speak. :Banane01: :cheer:

 

[keefer]

Fortunately I have a station just around the corner that sells 110. It is leaded but it is only $5 a gallon right now. We can also buy it for $4.50 if we pick it up in Nashville in a 55 gal drum. Good enough for rec use. It seems to run very well and the engine is staying clean.

 

[keefer]

Magoo....

Whats the deal with the dry pipe needing higher octane on stock motor then say a Bpipe? I thought the primary idea of high octane was to control premature explosion of the gas under pressure. I had the idea octane was purely a decision of compression psi.

I have a good idea on how pipes works and such, but dont understand why a dry pipe would call for mroe octane.

Thanks

I dont know as much as Paul but I do know that a dry pipe will allow the engine to achieve a higher cylinder pressure at high RPMs. This effectively makes the compression higher at fast engine speeds thus increasing the risk of detonation. The measured cranking compression is just one of several factors that play a part in determining what type of fuel your engine will need.