Leaded or Unleaded Fuel

[peterjank]

Hi all,

Is the Sunoco fuel sold at Norway\CHMS leaded or unleaded?

If it is leaded, does anyone know if a Rotax engine can burn unleaded fuel?

[JET Karting - Andy Finke]

The Sunoco Standard that is spec for everything but Rotax is leaded, and is the same spec fuel as the Manufacturers Cup runs.

Rotax spec is Sunoco 260GTX, which is unleaded. Rotax spec oil is the motul that Rotax national has you run.

We have both in stock.


Andy

[JAYKAY]

Here is a link to the Sunoco website:

http://www.sunocoinc.com/site/Consumer/RaceFuels/TraditionalFuels/

The "Standard" is their 110 octane leaded race fuel, and it has a couple of properties that make it pretty different from the usual unleaded pump gas. Besides obvious lead and higher octane it has a very low Reid Vapor Pressure (RVP) of 5.6 lbs and contains no oxygenate. I am not sure that a kart engine would operate at its peak with pump gas, but I would bet that an unleaded race fuel would be fine.

As a starting point, some stations around us sell 100 Octane Sunoco 260 GT Unleaded (under the Cam2 label) at the pump. It has less octane, and is not oxygenated but the RVP is in the 6.6 range. I cannot believe that these engines are getting the most out of the 110, so octane will probably not be a problem, and RVP is still low enough to prevent vapor locking. I am not sure if that is too much of a problem in karts since the carb is hanging off the side of the engine and not locked away in a hot engine compartment.

Long story short, my thought (and Martin, jump in if you feel differently) is that there is no reason that the engine would be ruined, but it would require different jetting to run at its best. Since a 2-stroke has no valve seats, I am not sure why we burn leaded in the first place, other than the fact that the Sunoco man makes a delivery and that ensures that we are all running the same fuel and takes more voodoo out of the setup.

Jim

[JET Karting - Andy Finke]

Jim-

Your on the right track. The main reason for the spec fuel, oil, and tires is to take the big budget testing and 'chemistry' out of the equation. We spec the 110 mostly because it is the same when you run nationals, if you choose to race that level some day.

Rotax needs to run unleaded to keep from gumming up the exhaust valve. They also run the Motul oil at a recommended 3oz. per gallon. You'd torch the Leopard at those ratios, but the Rotax does fine, and you can't get in to scrape buildup off the head since it is sealed.

For practice, we don't care what you run. I advise against pump fuel becasue it is not consistant at all, but most race fuels would work well.


Andy

[Jim R]

Anyone concerned about CANCER!!!! And please do tell me the amount is so minor it will not affect us.
Jim

[peterjank]

Hi guys,

Thanks for the info!