Hello Everyone, I have an idea and I want to know if its feasible before starting.

I have several old 60 size engines from the times of pattern flying (Rossi, Webra, OPS, HP, and others)

Im thinking in converting them to gas, but I would really want to avoid the Electronig Ignition,

My idea would be to attach a Walbro carb and connect the regular glow plug to a 1.2 v battery to maintaing it ignited.....

Is this feasible.....???

In advances thanks a lot for your help.

VĂ*ctor

A constant HOT wire and gasoline do not mix well. That's why a spark plug only sparks when the gas vapors are fully compressed at top dead center.  Doing what you suggest would result in flames and a possible small explosion. Don't even try it.

Um. What about the new NV 40 that runs on gas and castor with a glow plug?

There is a LONG thread on running engines on a glow/gas mix with a glow plug.
http://www.rcuniverse.com/forum/m_8009384/tm.htm.

To remove all acid combustion traces from my glow engines, I used to run them on gasoline mixed 50/50 with ATF at the end of the day . They ran fine as long as the plug was lit. Extra oil in the mix also reduced needle sensitivity when running gas. Using 50% ATF oil in the mix allowed about the same needle setting as for glow fuel.

There is a member here in the forum that has been doing just as you suggest, but with gasoline engines. I generally do not recommend converting glow engines to gasoline because they will run too hot on gasoline, and be very finicky on the needle valve adjustments. (There usually isn't room for a Walbro carb to be fitted on .60 size engines, and if you do manage it, it will block a lot of the cooling airflow.)

Just the same, this thread might interest you: http://www.rcuniverse.com/forum/m_80..._1/key_/tm.htm

Your best option would probably be to sell your glow engines, and invest in gasoline specific engines.

AV8TOR

The better way around is sticking to glow fuel, and fit an Rcexl ignition + 1/4"x32 spark plug. Learn how to adjust the needles. One click sometimes  is plenty.
So far, all who converted to spark ignition with glow fuel were raving about it. Ease of starting, lower reliable idle, smoother running, lower fuel consumption.

I'd be interested in doing this. What glow engines are good candidates for this and can methanol castor fuels be used?
Any links for this?
Thanks,
-Gary

Yes you can put a Walbro carb on a engine. I did it here with a 9cc gas engine. You need to make an adapter for it of course, but it works. Using a glow plug and keeping it lit up with a on board glow ignitor works too. You may be able to get a extra hot heat range glow plug and only need to keep it lit at lower RPMS too. You can also use muffler pressure if you don't use a Walbro carb. Maybe adapting a Evolution gas engine carb from their 10cc gas engine.

NV engines GX40 uses a ultra Hot Turbo glow plug along with other modifications to get their little engine to run gasoline with a glow plug. It actually works pretty good like that too.

For 10cc gas engines I would suggest running at least a 25:1 fuel too oil ratio as the bushed connecting rod still needs the oil a 20:1 ratio if the engine needs to be run in. I use Stihl Ultra synthetic oil in my small gas engines. But In my NV engines GX 40 or 6.5cc engine I use Klotz Benol at a 14% oil level as the manufacturer suggests using it with that engine.

You cna also contact the folks at CH Ignitions about getting a engine converted to using Spark Ignition. Their slip ring adapters for the engines works really good too. I would suggest using a engine that has more cooling fins on it for a gas conversion.Some glow engines have very little in the way of cooling fins and may not make the best choice for a gasoline conversion. But it depends on what you are doing of course.

I still say unless you modify the engine internals to run gas I think the basic glow engine will eventually destroy itself. Just throwing a Walbro type carb on and just firing it up won't work very well.   Short term , maybe .    Could be wrong....but.

If it looks like an engine, smells like an engine, and sounds like an engine... It's an engine. They do not care what they run on as they are fancy air pumps. I've ran gas engines on a glow plug... 4hp Briggs and Stratton lawnmower on gasoline and hot glow plug. It ran decent. Weed wacker needed glow heat kept on it to stay running until I put some glow fuel in the gas. Ran well.

Gas engines will run glow fuel fine as long as the carb can flow enough. Glow engines will run on gasoline fine so long as the needle has fine enough threads. Glow carbs on gas tend to be touchy; as Earl said one click can be quite enough. However, glow engines running on gas will lose 15-35% of its power on gasoline. Will a glow engine on gasoline and a glow plug start a fire? Only if you're an idiot.

If you can deal with the loss of power on gas, go for it. IMHO the better thing to do is CDI on glow fuel. More power yet, better fuel economy, better idle and transition characteristics.

Likely has been answered already, but does the nitro content of glow fuel ignited with a ECDI have the same effect as with glow plug ignition? Still a function of compression ratio of the engine (Hi comp = low nitro and vice versa)? Or, is detonation/pre-ignition obviated by the proper timing of the ECDI?

Thank you very much.

Well, those who converted their glow engines over to use spark ignition report better idling, better throttle response, and upwards of a 6% improvement in performance. That is using glow fuel for both methods if ignition. Now then the twin engine and multi-cylinder folks converted a number of glow engines over to spark ignition so that they could make the engines more reliable as one cylinder is always too rich and the other tends to be too lean. So spark ignition appears to improve on that considerably.

Yes the compression ratio is still important. Higher compression less nitromethane in the glow fuel and vice versa. Similar effects with gasoline where higher compression can result in detonation or pre-ignition too. So one has to come up with a balance or compromise as to how much of a compression ratio they can use. It would vary depending on the propeller size and pitch too. Ignition timing of course is still a factor as well. If you advance the timing too much you get pre-ignition too. Or you retard it too much and the engine looses power and overheats.

The engine does not care if it is gasoline or glow used for the fuel as long as it gets ignited to it can burn properly. Glow engine carbs have to flow more fuel as the air to fuel mixture is very rich. But gasoline engine carbs has to work at much more lean air fuel ratios and the proper ratio is at a very narrow range which is why you see more complicated carburetor setups for gasoline engines. Now the connecting rod and the cylinder plating method governs how much oil you can use in the fuel though. Some modern gas engines can run as little as a 100:1 fuel too oil ratio and work fine where other engines may need a 20:1 ratio with more oil to work OK.

Interesting that apparently some .60 size glow engines have room for a Walbro carb. When fitting a Walbro carb to my Super Tiger .90, I had to grind away at certain areas of the front of the engine, and turn the carb slightly sideways to get it to fit.

I still don't recommend converting glow engines to gasoline, but if you are determined to do so, here's a hint. The Zama carbs have somewhat smaller outside dimensions than the Walbro carbs.

For people who want to go the other way, converting a gas engine to alcohol or glow fuel, the WT-499 Walbro carb is made for use with alcohol and has larger fuel passages. When converting a gas engine to alcohol, you will usually see a nice power gain, and the engine will run cooler as well. You should check on the availablity of menthanol in your area if thinking of doing this as some people have problems finding it. It can usually be found at automotive speed shops, or at go kart racing supply outlets. An engine will consume double the amount of methanol than it does on gasoline. (Your airplane fuel tank will last 1/2 the time it would when running gasoline.)

AV8TOR

Stay on glow fuel, and use spark ignition. That is the easy way which has many advantages.
A glow engine on gasoline is disaster, unless a few adaptations are made to the engine, of which increased cooling capacity is the hardest.

+1

AV8TOR

to anyone if you want gas just buy a gas engine>> i sold my nitro engines at a swap meet most where beginners getting started>> some i sold the plane and engine very easy way to get a gas engine

I sent you an e-mail.
Thanks,
-Gary

That is total bull. My friend has been flying the OS GGas 15 and 10 for months and they run great. Flew one of DL 30s Sunday with OS Gas Glo plug.Run better then it did on the Ignition. I could not fault in any way and I built ignitions for 35 years. I will admit I had a bad Ignition in this plane.
could not believe how well it run. Neither could any one else at the field.
BCCHI Tired old CH guy.