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-   -   Is AVGAS=Aviation Gas Safe to run? (https://www.rx7club.com/rotary-car-performance-77/avgas%3Daviation-gas-safe-run-137696/)

Resource 12-03-02 08:33 AM

Is AVGAS=Aviation Gas Safe to run?
 
AVGAS=100 octane low lead=aviation fuel



My Power Doesn't use my 02 sensor so will this be okay for me to run?I'm just thinking of a way to buy cheap race gas.

A friend of mine will sell it to me for 2.10 a gallon.


Is this safe on the motor?

Thanks

Rotortuner 12-03-02 12:44 PM

It should work allright. ask him if you can get some 100LL thats 100 octan Low Lead. Thats pretty good stuf to use. I htink around here the 100LL runs about $2.40/gallon. Just dont let the DOT catch you using this stuff, i am not sure about where you live but here we have gas tax, and that tax is on fuel that is used for road driving. if they find out people are buying airplane gas thats not being taxed they will get pissed.

CJG

importboi22 12-03-02 01:58 PM

ya i ran 100LL no probs at all... i run usually a mixture not sure if its safe tho 5gals of 100LL and 10 gals of 91... i havent had any problems before... but then agian my motor is tired and has low compression on the front rotor...

fdracer 12-03-02 04:16 PM

where do you get your avgas from importboi? i live pretty close to corona and am interested in some.

Scalliwag 12-03-02 06:50 PM

Only run av if you do not have CAT's!!! This is very important because you will clog a CAT really quick. When they say "low lead" they are meaning low compared to regular av gas. There is still a shite load of lead in this stuff. Guess how I know?

Evil Aviator 12-03-02 08:11 PM


Originally posted by Scalliwag
Only run av if you do not have CAT's!!! This is very important because you will clog a CAT really quick. When they say "low lead" they are meaning low compared to regular av gas. There is still a shite load of lead in this stuff. Guess how I know?
LOL, you are correct, 100LL has about the same amount of lead as did regular leaded automotive pump gas, but I'm afraid to ask how you know that. :D

http://www.eaa.org/education/fuel/autogas_vs_avgas.pdf
http://www.dragracingpinoy.com/tech_avgas.html

Scalliwag 12-03-02 08:37 PM

Like everything else I have ever learned, I learned it the hard way! ;) Messed up a cat about 8 years ago and was not able to get a legit inspection until $250 later. It was not worth it.
But if you don't have cats it is cheap way to get more power.

lane_change 12-03-02 11:02 PM

I ran 100 octane in my Eclipse GSX last year for street racing in KC and on the way home that night, my motor popped. I am not sure if it was the gas, the racing, or the tuning but she took a shit the one and only time that I ever used it. I can get you all sorts of octane from 110, 114, 118 you name it. I can also get methanol if you want.

Resource 12-03-02 11:48 PM

Lanechange,where can you get this and for what price?

lane_change 12-03-02 11:54 PM

I get it right here locally in Kirksville, MO. I will get you some prices. Do you want to know by the gallon or by the barrell?

Rx7carl 12-04-02 09:47 AM

Yea but wouldnt this be a huge waste of $$$ on an n/a rotary?

Rx7carl 12-04-02 09:48 AM

stupid double post

Scalliwag 12-04-02 10:10 AM

Ouch!

Resource 12-04-02 10:12 AM

I need prices on the gallon and by the barrel.

I have zero Cats and no O2 sensor so it doesn't matter what I run.

lane_change 12-04-02 01:30 PM

I'll get you some prices by the gallon and by the barrell. Scott

Scalliwag 12-04-02 01:51 PM

We used to be able to go to a small private airport and fill our cars up. That was the way it was all over. I would guess those days are over. I have not tried to in years.

nimrodTT 12-04-02 02:01 PM


Originally posted by Evil Aviator

http://www.dragracingpinoy.com/tech_avgas.html

After reading this page and more than a few others, it looks like toluene is the way to go instead of avgas. Who's put toluene in their tank?

Scalliwag 12-04-02 02:30 PM

Scalli will wait until someone else tries this! It does sound like the guy knows what he is talking about, but I've been bullshitted before and I will be again I'm sure.

Rx7carl 12-04-02 04:47 PM

What about using 80 octane in an N/A rotary? ANy thoughts? Anyone? Bueller?

Scalliwag 12-04-02 04:59 PM

Why would you want to even if you could? It's lower octane than pump gas.

80-CU.IN.T 12-04-02 08:11 PM


Originally posted by lane_change
I ran 100 octane in my Eclipse GSX last year for street racing in KC and on the way home that night, my motor popped. I am not sure if it was the gas, the racing, or the tuning but she took a shit the one and only time that I ever used it. I can get you all sorts of octane from 110, 114, 118 you name it. I can also get methanol if you want.
AV - Gas will work but you have to tune for it. You will run leaner. I don't know the BTUs.

Resource 12-04-02 09:44 PM


Originally posted by 80-CU.IN.T


AV - Gas will work but you have to tune for it. You will run leaner. I don't know the BTUs.

Why would I run leaner?If it's 100 then it should burn slower correct?

HWO 12-04-02 11:25 PM

you can run leaner safer, you can run more advance safer, both of which = MORE HP

but as someone said, you have to tune for it.

Rx7carl 12-05-02 06:47 AM


Originally posted by Scalliwag
Why would you want to even if you could? It's lower octane than pump gas.
Then it'll burn quicker wont it? If 87 is preferred for N/A applications cause its whats availible, then if a lower one is availible maybe theres a gain? I dunno, just asking for any opinions, educated guesses.

Scalliwag 12-05-02 07:30 AM

Hmmm, it is just so far out of the normal paradigm that I cannot see that working. I think the slower burn on the higher octane leads to carbon buildup is the problem. As far as performance I am pretty sure that the higher octane gives it more "go-go".
Of course I could be wrong but even the people running "All-motor" class are running racing fuel.

Rx7carl 12-05-02 10:21 AM

Octane isint the determinante factor of power in a gallon of gas. There must be a "theoretically" correct octane for an N/A rotary at it's stock compression. And I never subscribe to anything that cant be shown to be true. Just cause eveyone runs race gas in "all motor" class doesnt mean anything. I'm sure NSU Wankel and Mazda have studied this during the R&D work.

Scalliwag 12-05-02 02:23 PM

While not subscribing to the normal train of thought on many things may be understandable. I would think that people have ran their NA's on pump gas and if it ran better they would not be paying $10 a gallon to run something that makes their car run slower.

88IntegraLS 12-08-02 02:59 AM


Originally posted by Scalliwag
Hmmm, it is just so far out of the normal paradigm that I cannot see that working. I think the slower burn on the higher octane leads to carbon buildup is the problem. As far as performance I am pretty sure that the higher octane gives it more "go-go".
Of course I could be wrong but even the people running "All-motor" class are running racing fuel.

The efficiency fault of the rotary engine seems to be not burning the fuel fast enough, as the air / fuel mixture will still be burning well after the rotor passes the point of maximum leverage on the eccentric shaft during the combustion cycle. If a quicker burning octane fuel could be used while avoiding preignition and detonation, its greater energy release per unit time could theoretically be set to occur right in the stage of maximum mechanical advantage on the E.C.

I would guess that retarded timing and / or water injection with some clever tuning could make a workable N/A rotary engine on 80 ocatane. Maybe even a tad more power could be extracted if one could harness the quicker burn properties w/o blowing up the motor :hahaha:

Good job on those housings Scalliwag, I would buy a pair if I could afford it:)

HWO 12-08-02 04:14 AM


Originally posted by Scalliwag
Hmmm, it is just so far out of the normal paradigm that I cannot see that working. I think the slower burn on the higher octane leads to carbon buildup is the problem. As far as performance I am pretty sure that the higher octane gives it more "go-go".
Of course I could be wrong but even the people running "All-motor" class are running racing fuel.

Because it combusts slower, you can run more advance, and thats what gives more HP

simply putting higher octane fuel into your car doesn't achieve jack if you dont tune for it

RICE RACING 12-08-02 04:40 AM

yes rotaries are wierd compared to piston engines, you gotta remember that at around 7000rpm a piston engine only realy has say around 4m/s to burn the fuel before the exhaust valve opens, where as a rotary has 6m/s to do the same job (because of the gearing of the rotor relative to the crank) You have allot more time to do the same job, hence some of the timing you can use and the fuels that will or can be burned seem so far from the norm.

But I think allot of guys forget that you realy have a 1/3 more time available to do "work" combine that with allot of other factors such as spark configuration and different burn (heat release) rates of various compositions of fuels and you got a fair few variables to play with :D

Some "unconventional" methods can be exploited, such as low octane combined with less advanced spark lead combined with T&L firing together (which increases burn speed) and there are many options available for increased performance while still getting efficient combustion, what is the exact best method/combination ? There are many ways to skin a cat :D

nimrodTT 12-08-02 04:48 AM

Given everything else is equal: running lower octane gas will give no benefit. It has been said already in this thread that octane rating is not a power rating. The octane rating also tells you nothing about the speed of the fuel's flame front. Octane only tells you its resistance to pre-ignition. Here is how it goes; I'll try to keep it short:

1. You need a higher energy fuel to make more power (all other things being equal). This higher energy fuel has the potential to burn stronger in the chamber of the engine, which can create more power.
2. You need a higher-octane fuel to run more timing advance without pre-ignition (all other things being equal). This additional timing advance can allow the fuel that is in the chamber to burn earlier and/or more completely. This also has the potential to make your engine more efficient and/or powerful.

The way I see it, you put the two together and you've got a pretty good combination.

Rx7carl 12-08-02 08:34 AM


Originally posted by 88IntegraLS


The efficiency fault of the rotary engine seems to be not burning the fuel fast enough, as the air / fuel mixture will still be burning well after the rotor passes the point of maximum leverage on the eccentric shaft during the combustion cycle. If a quicker burning octane fuel could be used while avoiding preignition and detonation, its greater energy release per unit time could theoretically be set to occur right in the stage of maximum mechanical advantage on the E.C.

I would guess that retarded timing and / or water injection with some clever tuning could make a workable N/A rotary engine on 80 ocatane. Maybe even a tad more power could be extracted if one could harness the quicker burn properties w/o blowing up the motor :hahaha:

Good job on those housings Scalliwag, I would buy a pair if I could afford it:)

Thank you, you get what I'm saying. I'm talking about not using H2O inj however, and setting the timing to what the engine needs to make its best power. Basically REALLY tuning the ign for best power.

Rx7carl 12-08-02 08:46 AM


Originally posted by HWO
Because it combusts slower, you can run more advance, and thats what gives more HP

WRONG!!!!!!!! more advance = more negative work in the engine. Higher octanes dictate more spark advance because they burn slower, so they need more time to burn, so you start the spark earlier. The downside of the early spark is that the start of the burn is too early and is actually trying to STOP the engine and reverse it! Especially in a rotary because of its narrow long combustion chamber we have a long burn which dictates a quick burning fuel to extract the maximum energy (i.e. burn it all) without having to advance the spark into the realm of negative work.

Scalliwag 12-08-02 10:02 AM

There is a lot of very interesting thought here. Since our motors do use such a unique combustion process gasoline is probably not even the best fuel to use. What I mean by that is that with the optimum tuning and the optimum fuel to achieve the highest amount of horsepower there is probably a more desirable fuel or blend of fuel to achieve this. I just doubt that lower grade pump gas is the trick. The link refered to earlier that talks about how racing fuel is made may explain why all the "all motor" class rotaries run racing fuel. Maybe it is not the octane but the additives?
The biggest problem would be all the testing and tuning and blowing shit up trying to come up with this. To find advisors in this field would probably be a royal bitch.
But I think most of us are pretty used to knowing that we have to rely on ourselves much of the time.

A professionally built engine dyno, a lot of extra time, and good beer would be needed to really be able to get a project like this to work. You need something generating numbers in real time. You would also need a bullet proof motor. Probably some specially made one piece apex seals from a high strength stainless to hold up to as much abuse as possible.
If a temp sensor could be tapped into the rotor housing with a small tube going to the inner wall of the rotor housing you could at least stay a little ahead of failure.
My idea is that if you ran it tuned to pump gas so you could get an idea of where the temperature can safely be. At least that gives a starting point.
Otherwise you could find out what makes the most horsepower may just melt the motor at the end of the first pass.
I have never had first hand experience with an engine dyno so I don't know if there is a temperature sensor for the exhaust or not. If there is then the only place the sensors would come in handy would be running in your car. You could use the same setup I drew up for having a constant compression reading for testing my housing resurfacing mainly during breakin.
Here is an exaggerated view of what it would look like. You would change out the fitting with a sensor.
You would use a length of stainless brake line (because it is strong enough to withstand press fitting for sealing in the water jacket) Note that where the hole breaks the inner wall it is smaller than the tube.

I know this is a lot of jabber but if any of you guys are serious on trying to find an optimal fuel this may help you save motors in the process. This experiment could cost a lot of money before fruition is gained depending upon a lot of luck. Oh, and if you can stand behind a safety barrier during testing woukd be a big plus. Just in case you use a fuel that creates a rotary pipe bomb! ;)

http://webpages.charter.net/mikeroberts/compdrawing.jpg

Scalliwag 12-08-02 10:16 AM


Originally posted by 88IntegraLS

Good job on those housings Scalliwag, I would buy a pair if I could afford it:)

Even at this stage of the game they would be $300 each to do them. If it works out and I get the spray equipment that price "should" come down though.
If you haven't visited the thread lately you may want to check out who offered to help test them ;)

ASE_Joe 12-08-02 10:49 AM

yes, most engine dynos are equiped with multiple EGT probes. At least all of the ones i have used have them. I havnt dynoed a rotary, ,but have done many piston engines. I have seen exhaust temps range from the low 500*Fs (very rich alcohol engine) all the way up past 1300*F. I dont think fuel had much to do with this though. Never experimented with just that. The mixture and timing seemed to be the contributing factor.

Scalliwag 12-08-02 11:25 AM


Originally posted by ASE_Joe
I dont think fuel had much to do with this though. Never experimented with just that. The mixture and timing seemed to be the contributing factor.
Right. I doubt that very many people setup motors on dyno's for testing homemade fuel blends. Even less have tried it with rotaries probably.
But the biggest danger in this testing is going to be detonation and high combustion temperature.
The first numbers I would want to see and monitor when the motor started would be these temperatures though. Otherwise testing may be over before it even gets started. If they are little high make it richer and see if it plays out.

So has anybody dumped toluene in there tank after reading the link?

Rx7carl 12-08-02 11:35 AM

Good points Scalliwag. I think the truth is that we really don't know, hell maybe even they dont know why they run that fuel except that it makes more power. I was just throwing out q's with some educated guesses. And thats why I was wondering if NSU or Mazda data on the subject was availible. Your right that it would be a MAJOR undertaking to try to solve this correctly. And prolly not worth it realistically. :)

88IntegraLS 12-08-02 12:06 PM


Originally posted by Scalliwag


Even at this stage of the game they would be $300 each to do them. If it works out and I get the spray equipment that price "should" come down though.
If you haven't visited the thread lately you may want to check out who offered to help test them ;)


If that surface you spray and machine on is as good as it sounds, $300 each is still a bargain. They are cheaper than stock and milled to the same tolerance, but with a surface with less friction and more resistance to wear.

It all comes down to my lack of funds! Same sad FC story :sad:

Scalliwag 12-08-02 12:55 PM

Just be sure to tell all your friends not to throw away their galled housings! Hopefully at the end of the testing phase you will have $600 (plus the shipping) I can do a set for you ;)
I may start buying galled and chrome flaked housings and some of you may be able to get sets done by trading in useable cores, or at least bring the cost down that way.

So if we want fuels that burn off quickly I would venture to guess that if we used something that burned off to quickly we could control that a lubricating material to help reduce the inherant friction on the internal components. That would seem to be a good trade-off to me. You slow the combustion process with a lubricant.

I always wanted to throw some graphite in a tank to see how and if that would work. My dufus ass theory would probably only work if you did not use a fuel filter.
Of course that is a really fugged up idea, but hear this out. The fuel would burn off and the graphite residue would penetrate all cavaties down to the smallest pore.
That SHOULD reduce a lot of friction and possible restore compression and possibly oil seal.
I never had a motor I disliked enout to try that on though.
When I get in my garage I think I will mix some in some gas and put a small amount in an open container and ignite it.
So be sure to watch the news just in case this goes bad! I would like to see what the graphite residue was like after the fuel burned off. If it became sticky or just burned off it would not be a good thing. If it kept it's original properties that would be promising.

My neighbors always like me to tell them when I am going to be experimenting so they can get their kids in the house! It ain't that bad but they do get puzzled looks on their faces sometimes when they see all the weird shit in my garage ;)

nocab72 12-08-02 08:30 PM

There have been a couple threads in the past months with some people sharing their "toluene" experiences.

K

Scalliwag 12-08-02 08:40 PM

good bad or both?

protlewski 12-08-02 08:58 PM

Hell scalliwag If I lived next door to you i would help you with those exps. I like seeing things blow up! :devil:

Scalliwag 12-08-02 09:06 PM

Damn, if I lived in Key West I would be scuba diving so much I would not have any time for my wankel projects! Do you have any buddies with a dive boat? ;)


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