Hey people, ive seen this term, but i dont know what it means!!

i know that it has something to do with how the aircraft is powered but thats all....

please help..

desil engine basicly only it uses nitromethane instead of desil (ok... so i cant spell or type) go to www.towerhobbies.com and look at engines. youl see.

a glow engine is a piston engine that pops from the heat of combustion (caused by the glow plug). very similar in some ways to a gasoline engine (which pops from the spark of a spark plug).

Most glow engines run on alcohol. Most spark engines run on gasoline.

... was my corilation to desil which is exactly like glow with a different compresion rate incorect? (they ahve "glow" plugs to ya no...

thanks guys, your help is much appreciated

Glow just gives you that feeling of "authencitity" (Balsa Master : I can't type either.) that can never be achieved with electric.

I like da real sound.

you could turn your car on and stand next to it when you fly

Glow and diesel (Thanks spell checker) are not the same. Diesel uses a variation of gasoline. It sucks in AIR (not an air/fuel mix) and has extreemly high compression. Once it reaches max compression, fuel is SLAMMED into the cylinder (That's that god-awful knocking sound you hear from big trucks). The high compression heats the air to the point where the fuel is immediately ignited upon injection.

The Glow Plug in a diesel engine is only used for cold weather starts when the heat of compression needs a little help.

A Glow Fuel Engine works through a chemical reaction between the fuel and the Platinum filament in the plug. Heat only augments the reaction.

note that i mentioned the fule difference...both engines compres the fule to a point of self detonation with no "spark" liek in most cars.

True for diesels but not for glow. If a glow engine used the heat of compression to ignite the fuel, we wouldn't need the glow igniters (except in the winter).

Our glow engines are actually closer to gasoline engines than diesels.
Dennis-

I'll go with your definition MinnFlyer. A glow engine will fire (not very often) with no glow starter attached, just the pure chemical reaction. The heat just helps the odds is all. After it fires a bit the platinum gets hot and no starter is needed to sustain the reaction. It's a lot like a gas engine, you just need glowing platinum, no spark, to ignite the fuel. Now here's a question. Would a glow plug with a plain steel red hot filament fire? I'm guessing not, if it's really just a chemical reaction of the platinum and methenol? - Joe

Check my other post.
I deleted a mistake here..

Mike,

I have this same discussion with my son (a distributor for big diesel wreckers) who claims that a glow engine is just a diesel. Can't convince him of the difference. I will show him this discussion next time, however I detect a slight difference of opion here.

Larry

There are RC Diesel engines. You replace the glow plug and head with a head that allows for adjustable compression. In an RC diesel engine it's compression that ignites the fuel (as in a true Diesel engine).
Dennis-

I admit, I messed up.
Here is the definition of diesel:

A gasoline engine intakes a mixture of gas and air, compresses it and ignites the mixture with a spark. A diesel engine takes in just air, compresses it and then injects fuel into the compressed air. The heat of the compressed air lights the fuel spontaneously.
A gasoline engine compresses at a ratio of 8:1 to 12:1, while a diesel engine compresses at a ratio of 14:1 to as high as 25:1. The higher compression ratio of the diesel engine leads to better efficiency.

heres the web sight:
http://auto.howstuffworks.com/diesel1.htm

Actually, a diesel is more efficient because it's closer to a constant pressure combustion cycle than a spark ignition engine.

The fuel is injected, not in one big lump, but as the piston is going down on the power stroke, so keeping the force on the top of the piston for longer, making it more efficient.

So, within the bounds of practicality, a spark ignition engine is a constant volume cycle and a diesel a constant pressure cycle.

-David C.

Show this to your son Larry:

http://www.fly-imaa.org/imaa/hfartic.../v11-1-44.html

A diesel only needs a glow plug to help it warm up on cold days, but a model engine can't run without one. Bottom line... It's not a diesel

PS, They can, however be converted to diesel (which again proves that they are not diesels to begin with)

http://www.justengines.unseen.org/Davis.htm

GLOW,that is me after flying a new plane all day with friends all day with no wrecks.

Hey Terrell, what happened to that nice avatar of the Seduction?

[Would a glow plug with a plain steel red hot filament fire? I'm guessing not, if it's really just a chemical reaction of the platinum and methenol? - Joe
[/quote]

In discussions with the late Great Johnny Clemence (SP?) of Texas. He showed me the first spark plug that functioned as a glow plug in the 40's or 50's He had filed it down to get a hotter spark, and the tip began to glow red hot. So when he removed the coil/ignition the engine kept running.

It's just the heat from the coil not a chemical reaction. Platinum is used because it will stay hot.

Hi Mike,long time no hear from,I got business this summer, never had a avatar[sm=confused.gif]

There is a catalytic reaction between the fuel and a HOT filament that improves the combustion and makes it occur at a "lower" temperature. But, if the platinum wire never got hot, then there would be no combustion. If you crank over your engine enough, you may heat the filament enough to get the engine to start. This is because the piston is compressing the air which causes it to heat up. The heat is then transfered to the filament. Usually this is not sufficient to get the methanol to burn. That's why we use a "glow stick". This heats up the filament and gets combustion started. Glow plug engines run so fast that the filament stays hot once the engine is running. But be careful. If you idle your engine too long the filament may get too cool and the engine will stop.

Heat is the key to igniting the methanol. Platinum is used because it is stronger at high temperatures than most metals. Plain steel heated up high enough will definitely do the job. It just might not do it very long.

Hope this helps explain things.

Kerry

Couldn't resist having a go at this one. Most model aircraft engines are designated 2 cycle. Briefly, (2) cycle signifys that the fuel/air mixture is ignited EVERYTIME the piston comes to the top of the cylinder. However, what ignites the fuel/air mixture when the piston gets to the top of the cylinder is the, "glow plug". A conventional 2 cycle engine would use a, "spark plug". The glo plug retains enough heat from the previous ignition to ignite the fresh fuel/air (cylinder) charge when the piston comes to the top of the cylinder; the properties of compression make the fuel/air mixture much more volatile (explosive). The fuel/ air is ignited and the, "glow plug", retains enough heat to, do-it-again, the next time the piston comes to the top of the cylinder. The, glo-starter that is employed is just a battery connected across the cold glo-plug. Once ignition takes place the glo-starter can be removed and the ignition cycle repeats as described above, eh?

Platinum is not used simply because it is stronger than most metals at high temperature.

It is used because there is a catalytic reaction between hydrogen and platinum that lowers the activation energy of the 2H2+O2 => 2H20 reaction (combustion!).

... the same reason it is used in fuel cells, the catalytic converter in your car, and these nifty Coleman heaters: http://www.sleepingbagsandtents.com/...g.asp?prdc=148

while glow ignitors make combustion far easier, it is actually possible to start your glow engine without one. i know a guy up at the flying field that i belong to who one day was having trouble starting his engine. he got it to start once after much difficulty, he flew it, shut it off, and he gave up trying to start it again. he figured his glow ignitor battery must be low so he opened it up to put it on the charger and noticed there was no battery inside. he had forgot to take it off the charger at home and put it back in the ignitor. also, the filament is not just platinum. it is a platinum irridium alloy. two stroke lpugs have more irridium in the alloy than four stroke plugs do because platinum retains heat better. if there was a pure platinum brand and you put it in a two stroke, it would preignite every single stroke.