Saito running on gasoline!

[Martin Quartim]

Just watched Peter Bergstrom on I-HobbyExpo 2008 talking about the new Saito FG20 that runs on gas and he mentioned that Saito is working on adapting the same fuel system for the smaller engines. Now I am wondering if we will be able to use these new gas engines for CL. We pay down here U$ 45 for a gallon of Byron Y/S 20/20 !!!!  The savings would be incredible for us, heck I'd fly everyday 

Martin

[john e. holliday]

That would be great for some people, but, gasoline is very dangerous if not used peoperly.  Have fun,  DOC Holliday

[Howard Rush]

Where Martin lives they use gasoline to propel motorcycles between lanes of automobile traffic.  Saito operation would be tame in comparison.

[Jim Kraft]

I run both fuel and gasoline at times in my old spark ign. engines, and one thing I have found is when gasoline catches fire you can see the flame. When alky catches fire, all you see is the paint crinkling up on the cowl. Gives new meaning to the Spitfire, although my Madewell was the worst for this.

[Martin Quartim]

why gasoline is more dangerous then a gallon of glow with 20% nitro?

Martin

[Ralph Wenzel (d)]

why gasoline is more dangerous then a gallon of glow with 20% nitro?

Martin

Three reasons, at least. First, the vapor pressure (volatility) of gasoline is far greater than that of either methanol or nitromethane. Second, gasoline combusts through a wider range of fuel-to-air ratios. Third, gasoline burns much hotter than alcohol or alconol/nitromethane.

[Larry Cunningham]

Alcohol has greater energy density, right? It seems like the fuels with the more energy
density are less volatile (e.g. diesel). Or do I have that bassackwards?

I know that F1 cars run on alcohol. My question is: do they add nitromethane? I'm
guessing not. Same answer for castor oil.. ;->

I heard someone saying that if the Hindenburg had been filled with gasoline, it would have
been much more dangerous. Shoot, the thing wouldn't even fly!

L.

"If you're going to do something tonight that you'll be sorry for tomorrow morning,
sleep late." -Henny Youngman

[Ralph Wenzel (d)]

Alcohol has greater energy density, right? It seems like the fuels with the more energy
density are less volatile (e.g. diesel). Or do I have that bassackwards?

Not so. Gasoline produces much greater energy during combustion than methanol (or ethanol). I should have put this link in my prior response:

http://www.p2pays.org/ref%5C05/04432.htmhttp://www.p2pays.org/ref%5C05/04432.htm

I know that F1 cars run on alcohol. My question is: do they add nitromethane? I'm
guessing not. Same answer for castor oil.. ;->

Right - No Nitro in F1

I heard someone saying that if the Hindenburg had been filled with gasoline, it would have
been much more dangerous. Shoot, the thing wouldn't even fly!

Did you see the Mythbusters episode covering the Hindenburg? Apparently, the skin treatment/finish caused as much (maybe more) of the problem as the hydrogen!

L.

"If you're going to do something tonight that you'll be sorry for tomorrow morning,
sleep late." -Henny Youngman

[L0U CRANE]

Alcohol has greater energy density, right? It seems like the fuels with the more energy
density are less volatile (e.g. diesel). Or do I have that bassackwards?

Larry,

I'm not sure what you mean by energy density. If it is like BTU/lb, then, ideally, gasoline and kerosene produce more heat per unit weight. Gasoline about 20,000 BTU/lb; alcohols closer to 11,000 (with ethanol slightly 'hotter.')

Volatility at atmospheric pressure is not a factor inside our engines, where we compress the fuel/air mix to some sort of an optimum before we burn it. At atmospheric pressure, gasoline is fairly easy to light, and will burn fiercely.

High performance combustion engines can produce more power from alcohol fuel for two prime reasons:

The alcohols chill more when being vaporized - that improves/controls cooling better than the less volatile gasolines and kerosenes.

Methanol/ethanol can burn in engine combustion conditions over a much greater fuel/air ratio range.

...So, we can offset the lower specific heat yield of alcohol fuels by passing twice as much or more through the engine, and pick up the added cooling advantage. Gasoline- or kerosene-based fuels are much less tolerant of f/a ratio. They will stop burning at too rich a mixture setting. At the lean end, power is affected because all of the burnable fuel has combined with the atmospheric oxygen present, and some oxygen is left over.

Gasoline, kerosene and ethanol or methanol are all less dense than water by quite a bit. Gasoline and kerosene do not evaporate or vaporize as readily as the alcohols in our engine conditions. So, since the amount of fuel we can burn is dependent on tolerable fuel/air ratios, we can burn LESS gasoline or kerosene per revolution than we can alcohol. The quantity of air going through the engine's cycles sets more of a limit with them than with alcohol.

[Mike Greb]

Actually, F1 cars run on gasoline.  Indy cars used to run on methanol. They now run on ethanol.  The reason for alcohol is that plain water will put out fires.

[Martin Quartim]

in Brazil we have been runing cars on alchahol since the 80s and for sure alcahol gives the engine a lot more torque and power then gasoline, and my "guess" is that methanol is even stronger.

Perhaps I am wrong but i think I will need a Saito 91S gasoline to replace my Saito 72 running on 20/20.

In our cars we get greater milage with Gasoline , I am not sure how that would be on the Saitos FGs. But  if it also burn less fuel, we can count on have to carry less fuel weight in the nose.


Martin

[Andrew Borgogna]

My understand of the difference between gasoline and methanol is gasoline has more BTUs of energy per unit of measurement than methanol, but it runs at a much higher air to gasoline mixture ration.  Therefore for a unit volume of air you burn a much smaller amount of gas.  Gas runs at somewhere near 16 to 1 air to gas where methanol runs somewhere near 6 to 1 air to gas.  So even though gas has more BTUs of energy you can burn almost three times as much methanol before the mixture becomes so rich that additional fuel get tossed out the exhaust as unburned hydrocarbons.  This also explains why gas gives much better milage it runs much leaner.  At least that's the way I remember how it works.  Back in the days when I flew on the Dark Side I had gasoline powered planes (read chain saw motors) and never found it to be anymore dangerous.  It just required more care in the plumbing and different materials for the hoses.  I do confess I kept a fire extinguisher next to the plane when I fired it up.
Andy

[Scott Hartford]

I know a few guys that tried to convert some smaller Saitos to gas and found out real quick why they don't offer them from the factory. They ran way too hot and don't carry enough oil into the crankcase so the rod bottom wears quickly, or breaks.

[Wayne Collier]

I'm no chemist and don't pretend to be.  It is my understanding that we are primarily burning carbon to get power from gasoline or alcohol.  Gasoline has much more carbon per molecule so it takes less molecules to get the same power.  Methanol and ethanol are names of particular chemicals in the alcohol family.  Gasoline is the name of a chemical family that includes several particular chemicals.  Methanol is pretty much methanol.  Ethanol is pretty much ethanol.  Not all gasoline is the same.  It is usually a blend of chemicals with from seven to ten carbon atoms per molecule along with detergents and other ingredients intended to help give a consistent burn rate.  Many geographic areas of the U.S. have different blends of gasline depending on the season of the year and the emissions laws of the area.  If an engine is set up to run well on alcohol it may not run as well on gasoline.  If it is set up to run on gasoline it may not run as well on alcohol.  Some auto computers can compensate to a point by varying the air fuel mixture to achieve reasonable power on either fuel, but may still do better overall on one or the other fuel.  I have found that if you run a glow engine on fuels that are more energy dense than methanol you have to really up the lube.  When I was using a blend of ethanol and camp fuel (such as Coleman) I had to use about thirty percent castor to both control temperature and increase overall the volume of fuel to facilitate a reasonable needle setting.

Why can't I see the spelling errors before I hit the post button?

[dirty dan]

Actually, F1 cars run on gasoline.  Indy cars used to run on methanol. They now run on ethanol.  The reason for alcohol is that plain water will put out fires.

Well, I suppose one could refer to the fuel F1 cars use as gasoline--but it's not like any gasoline you and I can buy. Still, it is better today than it was several years when some of the F1 teams were using "gasoline" which cost several hundred dollars per liter.

Dan

[Martin Quartim]

Saito unveil a new Saito FG14 which is an Saito 82

http://translate.google.com.br/translate?u=http%3A%2F%2Fwww.saito-mfg.com%2Ffg14%2Ffg14.html&sl=ja&tl=en&hl=pt-BR&ie=UTF-8

I don't understand the basics of how this engine operates, but I'd love to have a engine that could use cheap fuel.

Martin

[Bob Reeves]

Just remember these are ignition engines requiring the added weight and complexity of the ignition componets.

[sleepy gomez]

This discussion is very interesting.  I recall some 30 plus years ago I raced my 100 cc Parilla kart engine using a constant lit glow plug on the standard gas/oil mix that the rules called for in a stock class.  I never pursued  development but initial testing showed it ran about as well as the spark ignition.

[bob branch]

In RC gas motors use cheaper gas, true. But they have a lot less power. You have to really go up motor size wise to get even. That means weight. Also you are going to have to carry an ignition system with a battery and that is all weight. That means more weight. Nothing comes as a free lunch. I fly an OS 1.60 on a 79 inch span 3D RC plane. That is 26.2 cc. It takes a 40cc  gas motor to give the same flight performance on the airplane. All up weight is about 11 pounds. Add to that they stink to high heaven as will your hands and clothes from the fuel. Plus their mufflers are pretty loud. They have cost a lot of clubs their fields. One of our local clubs just lost theirs last week due to the noise level of gas planes. Not trying to  shoot anyone down. Just trying to provide real world info. We  saw the prototype  at one of the local club's meetings just before the Toledo show when the gang from Horizon came and shared their new stuff. There would be a major balance issue with most stunt designs with a motor that heavy up front. My guess is a dedicated design would required.

bob branch

[Martin Quartim]

In RC gas motors use cheaper gas, true. But they have a lot less power. You have to really go up motor size wise to get even. That means weight. Also you are going to have to carry an ignition system with a battery and that is all weight. That means more weight. Nothing comes as a free lunch. I fly an OS 1.60 on a 79 inch span 3D RC plane. That is 26.2 cc. It takes a 40cc  gas motor to give the same flight performance on the airplane. All up weight is about 11 pounds. Add to that they stink to high heaven as will your hands and clothes from the fuel. Plus their mufflers are pretty loud. They have cost a lot of clubs their fields. One of our local clubs just lost theirs last week due to the noise level of gas planes. Not trying to  shoot anyone down. Just trying to provide real world info. We  saw the prototype  at one of the local club's meetings just before the Toledo show when the gang from Horizon came and shared their new stuff. There would be a major balance issue with most stunt designs with a motor that heavy up front. My guess is a dedicated design would required.

bob branch

Hi Bob,

for us there are several benefits of a big engine, so a low power fuel like gasoline makes sense to me. The problem is the weight, if we could custom make a light ignition system and make a 90 size engine work for C/L I think it would be very very interesting.

Martin

Martin

[FLOYD CARTER]

These days, the weight penalty for running spark ignition is a mere 2 ounces.  The spark coil (Larry Davidson) is just under 1 oz, and a Li-Po cell of about 800 mAh is another ounce.  Most people use a transistor coil driver, so add about 8 gm for that.

Remember that you need only about 1/2 the fuel load of gasoline, vs glo fuel.  So fuel weight savings makes up for the ignition weight.

Unfortunately, converted engines are no longer legal for competition.  However, there are many good spark engines of .40-.60 cuin available at reasonable cost.

Floyd in OR

[Martin Quartim]

Thanks Floyd for pointing me in the right direction, I just googled Larry Davidson) and found his list very interesting.

http://www.modelflight.com/larrydavidson.html 

Thre must be a good reason why converted engines are not legal. Why would that be?

Gas is very common among R/C modelers now days, have anything changed?

Who makes .40 .60 spark engines?

Martin

[john e. holliday]

Why can't we run the modern converted sparkers in stunt competition?  It has always amazed me when Jim Lee was running the old time sparkers how easy he made it look.  I see Davidson lists polyspan in new sizes.  DOC Holliday

[Steve Fitton]

Well, I suppose one could refer to the fuel F1 cars use as gasoline--but it's not like any gasoline you and I can buy. Still, it is better today than it was several years when some of the F1 teams were using "gasoline" which cost several hundred dollars per liter.

Dan

You must be referring to when Benetton was running the "special" fuel in Schumi's car....

[keith varley]

When I was a much younger guy , the glow plug was considered new technology , and the first one that was regularly available for modelers was brought out by Irving Ohlsonn.  Since the cost of early glow fuel was too rich for us poor kids and since our models , that where finished with nitrate dope , where not at all fuel proof for alchohol fuels , some of us used gas and 70 weight oil (just like the sparkie engines) , but by adding nitro propane , they ran on glow plugs . Is  this an idea that could be used in this day and age? Inquiring minds (cheap guys)would like to know. Keith Varley