Glow fuel is getting too expensive. But I dont want to fly giant scale gassers. I have a Super Tiger G90 sitting around. Is it feasable for a newbie to convert this engine to gas without machine tools? If so, what would it take and how would I do it? Could it be left a glow engine and run on gas with the addition of a pumper carb?


Thanks
Jim

Definitely feasable. I am running my old Super tigre S2000 on gas glow. walbro carb with a 3 to 1 mix. tapped the crank and ran a line to the pump cover. running 16% oil with 15% nitro. Would like to find 10% with that oil content and try that.

worth doing but I think machining is required, there are some videos on my site

Depending where you are buying from the fuel. Try 20-25% castor and 80-75% methanol and no nitro.
And you can get them at Very Low price if you just drive around the factories who use them for their
own products:
Castor you will find where they make Paint, or Food products like chocolate etc.
Price is below 4 Euro/liter and last week I found a place they promissed me 2 Euro per liter if I buy 10 liters
or more; they just do not want to bother with small quantities, they use something like 200 liters per day
in their production line.
Methanol is used massively by washing liquid makers and many paint making factories where they use like
300-1000 liters per day. The best price so far I got is 0.8 Euro per liter.
And with the price of Gasoline going up, added the weight of the Gas-carb + Ignition system and their
cost I abandoned my plans for flying on gas. In fast I just purchased OS BGX-1 one more engine and
I am going to keep it glow(35cc).
Cheers,
Nick

Hi Ken,

Been back to New Boston lately?

How did you convert your G90 to gas? Would it not be possible to just put a walbro carb on it and leave it glow? If so, what would I have to do to the fuel to make it function with a glow plug?

Thanks
Jim

See this thread: http://www.rcuniverse.com/forum/m_1267448/tm.htm

Also, BME engines sells Super Tiger .90 engines converted and ready to run. I have one running on Gas/Glow and it works great!

AV8TOR

I was there a couple weeks ago and will be there this coming week if things work out. Why would you want a wabro carb and still run glow? You can put one on and drill the jets so it will get enough fule

Walbro was reported to not(!) take well the Methanol/Nitro fuels on its membranes
and also on other parts even if you wahs it after the flights everyday with gasoline
it will still brake down. In general seems anything desinged to resist gas does not
resist Methanol/Nitro and the Other Way Arround. Well, the time matters indeed,
it is maybe OK for couple days prior destriction.

Ken,

Two reasons for the walbro. First, it is a pumper carb. Second, I was talking about running gasoline with a glow ignition. Saw the video on your website of the G90 on gas.

Only reason I am considering this to start with is that our clubs local supply of glow fuel has decided to get out of the business. Now if i want glow fuel I will have to order from Tower or some other source. I would have to order at least 4 gallons at a time and with hazardous fees and all looking at almost $25.00 a gallon with a minimum of 4 gallons per order, thats an outlay of $100.00. When compared to the price of gasoline, well you get the picture. All my planes and equipment are set up to fly 60-90 size glow and I dont have the budget to go shelve all my equipment and try to reoutfit into larger planes. Therefore the need to find an economical way to convert some glow engines to run on gasoline.

So I have a choice of converting them to run on electronic ignition or glow ignition. If I go with electronic ignition, the price of the ignition system is just as much or more than the engine cost to begin with. And would be a fairly complicated process where a lot of machine work would be needed to change the head to accept a spark plug and put bearins on the rod to accomodate less oil in the fuel.
If I can convert it to gas/glow, there will be no changes to the head. If I can find an adpater plate for the carb, all I would have to do is swap out the carbs. Using glow, I will be using gasoline with more oil content so I wouldn't have to change out the rod bearings.

I have been trying to read a little on the gas/glow thread but with only short times to read, the thread is so long that I am having a hard time following it. Looks like to run gasoline on a glow ignition, I would still need to mix in some glow fuel to keep the glow plug hot. What type of fuel mixture would I need? If a lot of glow fuel(nitro/methanol) is needed, the whole project may not be worth it anyway. What do yall think?

Thanks
Jim

I haven't been watching that forum, my opinion to get away from glow is to go to gas. if you fry enough you will save enough to pay for the ignition and will not have the mess, plus you pullup to any gas pump and get it. I haven't flown glow in years , I still have some engines but they don't get flown, I have some 60-120 sized planes and fly them all the time on gas, well worth the conversion!

One of the reason you want to use ignition instead of glow plug is you can set your ignition timing. With glow plug and gas you may get premature ignition and lost of power.

Borna

Borna,

Saw some of your conversion of the GMS 120. What did you do to the head of the 120 to accomodate the spark plug? BTW, I have a GMS 47. An awesome little engine. Even after 25 flights, when cold the piston still squeaks st TDC. Gobs of power and idles really low. If your 120 runs as well, you will be really happy.


Thanks
Jim

C-H sells 1/4"-28 spark plugs that they call Rim Fire for $16.95

Exactlly, that is what I used in my GMS 120. Same thread size as glow plug.

I think you are confused , the videos on my site have the same ignition as the big gassers the 2300 has a 10 mm cm6 plug the 90 has a 1'4 32 plug because there is not enough material to bore the head for a 10 mm plug.

Just to add a thought. I have been experimenting with E85 in my ST 51 ring. It seems to run great although it is down about 200 rpm's from 15% glow. It is a little more sensitive on the needles although not bad. Right now I have only run it on the bench and am getting ready to put it on my Super Sportster and fly it. Seems to be a practical solution as E85 is about the same price as premium gasoline here in the Houston area. I am adding about 5% nitro though which drives up the cost a little. It seems to idle better with the nitro and I also had to switch to an OS A3 plug from a number 8 to help the idle. Transition is not perfect but not that bad either. It is better from a low idle than snapping full open from mid throttle. More when I fly it. One last note - it uses less E85 per minute of run time over methanol fuel. I will have to time it to get an exact time difference but it seems to be a lot longer run on the same tank. Kinda makes sense because Stoich on Methanol is about 6.5:1, Ethanol is 12:1 and Gasoline is 14:1.

Would it be possible to leave the bushing/bearing if I add more oil to the fuel and go with the electronic ignition?

Does anyone sell a carb adapter for this engine?

Thanks
Jim

yes the bronze bushing works fine as long as you have 12-15% oil in your fuel.
contact http://www.nelsonhobby.com see if he has one for sale.

You also need to make the sensor housing and a hole to press fit the magent in drive washer.
Oh and don't forget the hole somewhere in the backplate or somewhere else for the pressure line to fuel pump on the carb.



Borna

They touched on this a little in the gas/glow thread. The problem with running that much oil in a gas engine is the carbon that will be produced. Glow fuel burns cool enough that the oil is not burned. Gas is hot enough to burn the oil, producing carbon buildup.

Wow,

The Nelson Hobby website says all I need to do is put the electronic ignition on it and use the Super tiger carb. Just need to run 15% oil in gasoline. What type of oil should be added to the gasoline? This would seem to be too easy. They actually showed pictures of a Super Tiger engine with the conversion on it. And made specific reference to the G90. If this would work it may be just what I have been looking for.

Borna,
Is that the ignition you used on your GMS 120?

Thanks
Jim

That'll be a very sensitive needle valve?

Jim I am in new boston now till about 4 tommarow evening if you want to see some parts call 903-277-2290

Jim, my ignition is from C.H. Ignitions

http://www.ch-ignitions.com/#cat
27. Single ignition 14mm spark plug Bosch resistor cap.

Borna

Just met with Ken a few minutes ago. Super nice guy. Showed me a couple of the ST conversions he had done. And explained a lot of how they were done to me.

I have one more question that I forgot to ask him. Does the magnet for the ignition system come with the ignition or do you have to find it separately and if so what kind of magnet is it? Oh, and where would I get one?

Ok, so thats more than one question. They just kind of built on each other.


Thanks
Jim

1/8" diameter rod magnet 1/8" long

http://www.rare-earth-magnets.com/detail-ID-100.html

From CH ignitions

41. Magnet, alinco nickle 5, 3/16 X 3/8 .................................................. ................................. $1.50
42. Magnet, selenium cobalt 8, 1/8 X 1/4 .................................................. .............................. $2.50