I was talking about de-carbonizing my engine with a piston-head friend of mine, and he suggested 110 octane gas to do the job. So, can a 12a with 132k, sterling carb, racing beat exhaust and no rats nest handle it, and if so would it even be any help in a rotary engine, or should I not bother?

 

the only thing higher octane does is run the engine hotter alowing less gas to be used.

 

why use a higher octane than u need 2??? unless you have higher compression than standard there is no need to. if you cannot compress this awesome fuel to what it's suposed be be compressed, you won't gain anything.it's a waste of $$$$$$.

 

My friend tells me that in a piston engine, burning hotter helps knock loose any carbon deposits, so, would it work on a rotary?

 

I thought higher octane ment it burnt slower, meaning less heat and less pinging?

 

Octane is only a measure of a fuels resistance to knock. To put it simply, it depends on the fuels molecular structure and how easy it is to break down. It doesn't necessarily mean it burns any faster or slower or performs better than a lower octane fuel. There are many other factors that determine how a fuel will perform in a given situation. There's been some very long threads on the subject so do a search.

 

Yeah from what I heard the reason for using higher octane fuel, is to prevent detonation, in turbo engines anyways.....Therefore wouldn't the fuel be harder to ignite, as the octane % gets higher? I am not 100% on this, don't flame if I am wrong...
If thats how it works, how would it burn hotter in a rotary or any other engine? Unless you have higher compression engine or a turbo setup.

 

anybody know if it's okay to run 87 octane in a streetported 12a?

Dan

 

87 Octane is all a NA rotary needs. Anything else is a waste of money.

This is assuming your timing is stock of course.

 

sooooo back to the SP question

 

i made a post on this a long time ago. basically came up with its useless, actually worse to run anything other than 87 unless your running turbo, S/C, or nitrous.

also, FYI, someone posted that when mazda ran the 787B, and alot of the first gen race cars, they had to bring their own "race gas" (87 octane) because the track didnt carry that low of octane. yes, the 787B won by 3 laps at la manes running on 87 octane.

 

People do listen to me! You made my day REVHED!

There's a thread called "another fuel octane thread" where I explain the differences between octane rating and fuel energy. As REVHED says, octane is independent of the energy stored in the fuel so you can't make any connections between the two.

 

Considering that the IMSA RXs and the 787B ran on pump gas, I would say there is no point to running 110. If you really want to heat **** up run a quarter gallon of denatured alcohol through it.

 

cool, I had a feeling that you guys would think it was useless. Thanks for the info.

 

yuh unless you are running boost, you will lose power with that high of an octane

 

Not only is 110 octain counterproductive in a rotary, I kinda doubt you would want to pay for 110 with the gas prices the way they are now.

 

MARVEL MYSTERY OIL

IS THE ROTARY SAVIOR!

ive restarted locked motors at 230,000 miles with that stuff and i put a full can in with EVERY oil change.

 

so yaaa that gas idea of 110 is a joke and a waste, ur compression/12a isnt made for that, waste, waste, the mystery oil will break it all up, change ur oil, put it in first, and 6-7500 rpm it highway style for 30 min, drive it like a mad man...

 

I've read on a Wankel Motor website that rotory motors ALLOW the use of lower octain. But I've run 110 and It ran better and faster. I could be wrong, but then again I noticed a difference. Unfortunatly 110 is about $2.60 a gallon where I get it and ...well... why spend that much money unless you going to the track. One things for sure, it will not run worse or slower w/ 110.

Oh and maybe this is just me but I would never run my car at 7500 rpm for anylonger than the time that it takes to get the revs up that high in order to hit the next gear really hard. I like my car and want it to last for a long time. I don't see how redlining your engine for a long period of time would help anything. I guess it would give you more reason to rebuild you motor soon

 

EVERY rotary race car I have ever read about runs on 87, unless it has forced induction. There is absolutely no need for anything higher on an NA motor.

 

as in reving high under load, go fast, blow out carbon. u rotary likes high rpms

 

You gotta remember these engines are completely different. While you can run a piston engine hard, say like on the highway and help loosen up the carbon that's built up on the valve springs/covers, you cannot do this on a rotary as there are no valves. haha

 

So if you run avanced timing on a bridgeport does that mean I should run high octane? I went to turbo my motor and the bloke said it would ping at anything higher then 3-4psi. So i must have a high compression motor right? tis a 12ab.

 

I would love to know who on the Gold Coast told you this because they are full of ****.

 

I thought the IMSA racers were using 80 octane at the track, not sure about the 787B though. Mmmm 80 octane.