What Gas do you Put In..?

[redliner1973]

The only thing insulating the exhaust pipe or header does is to keep the temps INSIDE the pipe high enough so that the burned gasses does not lose velocity going out the port. You may realise something, but remember that you have to compare it to a header without a coating. Example:

If header A has no coating, Gas moves at oh, say 400fps out the pipe (example only) whilst cooler ethanol runs at say, 350fps

So now you go out and coat the header.

Now, header blows out gas at 450fps. whilst ethanol, goes 400fps Yes, a coated header moved the ethanol out faster. but you have to comapre it to waht the gasoline does, not waht the coating will do. The Gas is still faster. the coating will effect BOTH fuel types equally. I hope this makes sense, as I have trouble explaining it!... :twisted:

[Anonymous]

No, you explained it very well. What I was trying to determine was that if gas with ethanol is a given then insulating the pipes might give back some of the loss. Obviously, if this helps a mixture, then it would definitely help with staight gas.

Harrison

[Anonymous]

Well...I used the handy dandy search feature to try and figure out what grade gas I should be running in my '83 550L. I was confused cause everyone I know around here (Boston) was telling me something different, and it seems as though that is what's happening in the forum. SO..My questions are...what exactly should I look for to determine if my engine is knocking/pinging? I know what it sounds like in a car, but as this is my first motorcycle I'm not sure if there is a difference.

Sorry to go back to this discussion, but I really do appreciate the help.

David

[Anonymous]

just listen for the same noises although they may be of a slightly different pitch. usually you wont have these kinds of problems as these engines are much more efficient than your car. if you do hear some sounds check to see that your carbs havent become either too lean or too rich by looking at your plugs. ( white is lean, black is rich, tan is about right).

[Pete's GS]

In the GS550 Chevron Unleaded 87 (about one cut above tomato juice). Bike runs fine. When the carbs were clogged and gunky when I first rescued it I put in premium, which has more detergents. Our mechanic recommended Chevron for the Acura and it's been fine. Supposedly it both prevents and removes deposits on the backside of intake valves. In So CA Union 76 is also said to have good premium as well. The XS650 gets only premium because it's 10:1 compression.

[Anonymous]

like someone said in one of the first posts, you should use the minimum rated gas that doesn't cause knocking... from my understanding of the internal combustion engine, none of our bikes will "perform" better with higher octane unless you're getting more compression in the cylinders. actually, i've heard this is how a lot of "racing" chips in cars work... compression ratios are set at the factory with the thought that most people will just put the cheapest gas in the car and expect it to run properly... the chip lets the engine know that you're not using the cheap stuff, so you can get more compression w/o any knocking. more compression = more power...

[Hoomgar]

Many theories. Here is mine as I have posted before. My experience is my "engines" in all my cars/bikes run much better on higher octane fuels. They also seem to run cleaner between oil changes but the best thing I can point to as any kind of proof for my findings is the fact that I definitely get better fuel economy with better fuels. Some engines more than others. Some may vary 1 or 2 mpg average but still run better. Most of my engines will give several mpg more on higher octane fuels and you can actually notice the performance increase as well as an overall quieter engine.

In my GS and my Chevy it actually works out to cost less to run the higher grade fuels than it does the lower ones due simply to the better fuel economy which I attribute more to the increased performance than anything else.

Other guys have not had the same experience so I encourage anyone that ever asks this question to keep an open mind to the possibilities of either way of going and see what you find for yourself.

[Planecrazy]

As I have stated in an earlier post, I always run premium in my bikes and small engines. They seem to run better and more efficiently (same experience as Hoomgar mentions) but, more importantly, if there is any truth to the claims that the "better" fuels help to keep the engine cleaner I see absolutely no reason to take a chance with lesser grade fuel. In my small engines, the presumed price penalty is more than made up for in reduced maintenance costs. ie(cleaner engine requires fewer expensive carb rebuilds over time than one that runs dirtier with lower grade fuel).

Is this true? I have no idea, but for the small difference in price (and the fact that my improved gas mileage balances this difference out to some degree), it's not worth taking a chance...

Regards,
Steve 8)