Gas versus glow engine. I have been in RC for a while and have always used glow engines, starting with 2 strokes now mostly 4 stroke engines. I would like to try gas but I am not sure what the trade offs are. In the 26 cc or 1.5 cu. in. size I know the gas engines weights more and gas is allot cheaper than glow fuel but what are the other trade off such as power or thrust, transition time and smoothest. What about over all ease of operation and RF interference. I want to try gas in a Cermark Pitts. What would be a good choice and how would it compare to 140 or 160 4 stroke glow engine?

Thanks for any help
Lee

lee1010,

I have just about fully made the transition from glow to gas. I think a [link=http://www.scottellingson.com/]Brillelli[/link] 26cc swinging an APC 17X6 prop at 8400 rpm would be just fine for the Cermark Pitts. I'm running a [link=http://www.scottellingson.com/]Brillelli[/link] 26cc on a GSP Giles 202 140 at 12.5 + lbs and if flys fine. It wont 3D at that weight but it fly fine other wise. I guess the equivalent to the 26cc would be like a 150-180 4 stroke. I fly mine with an FM radio but I'm going to a PCM, using FM is fine with the proper setup. The pros for gas are cheaper fuel, no batteries to lug around for a starter, no glow igniter, more reliable and last longer, and virtually no clean-up. One more thing, you can't beat the sound of a gasser . These little gassers run very smooth and maybe smoother than most glow of equal size and are easy to maintain and operate. It made a believer out of me.

Thanks Zippi that is great info, I was looking for that kind of input!
Lee

Get a Zenoah G-26. Its a better, more reliable, easier to set up engine than any brilleli will ever be. If you like to tinker with engines, and do maintenance, get the brilleri or similar exotic engine. If you like to fly all day, and never have to even think about your engine year after year then get the Zenoah

Have you ever owned a Brillelli ? I have seen more than a few people tinker and tinker on thier G26's. The brillelli is no worse than any other engine for tinkering and maintinence.

FWIW, not your size but to give you some sort of yardstick to start with. The Zenoah G20 (1.20) is designed to replace .90 sized 4c. So as you scale up to your size glow you can use the same ratio to get what size gasser you will need.
The take off weight on a glow will often be more due to the fuel needed in your size range, but the landing weight will be less cause you have burned off 18oz of fuel where the gaser is using 8-9 oz for the same flight.
This size range its hard to make a choice, larger and gas is it, smaller glow wins. Good luck

A g-26 would be good in that plane, or if you want more power a 3w28 would do the job well

p.s., ignore jettpilots comments on the Brilelli, he is full of sh@t

Crusty,

I second that, I like the Brillelli engines so much, thats why I'm switching to all gas. The engines are great and reliable and you can't beat the customer service. Just love the little 40cc.

If you like exotic engines try the RCS 140. Its a great match for the Cermark Pitts. But be prepared to tinker.

Thanks for all the commences and help. What is the weight deference of the Zenoah 26 and the Brillelli 26?

Thanks
Lee

on a whole you are not going to notice any reliability differences between the g26 and Brillelli. the main differences are weight and ignition system. both will be reliable but the brillelli will be lighter and easier to start because of its electronic ignition. both will perform in the same range however.

Hi could someone give me advice on a gas burner for this aircraft its a Sukoi Su-31M Arf I beleave was a Fun-Key Arf Kit No. FF 2003
sold by Yellow Aircraft. The specs are
Length 63.5
Wingspan 72.5
Wing Area 945 sq .in.Hi could someone give me advice on a gas burner for this aircraft its a Sukoi Su-31M Arf I beleave was a Fun-Key Arf Kit No. FF 2003
sold by Yellow Aircraft. The specs are
Length 63.5
Wingspan 72.5
Wing Area 945 sq .in.
weight 11-12 lbs
Engine 1.08-1.5 2cycle 1.20-1.8 4-cycle
Airframe bare weight 8 lbs
I don't intended to do any 3D flying Just aerobatic. but to fly with descent authority any help will be appreciated Thanks Greg.
weight 11-12 lbs
Engine 1.08-1.5 2cycle 1.20-1.8 4-cycle
Airframe bare weight 8 lbs
I don't intened to do any 3D flying Just aerobatic. but to fly with desent authority any help will be apprisiated Thanks Greg.

EI is nice for starting and smoother idleing. maybe less weight. On the other side of the coin you have to maintain a battery, switch that should be replaced every year if used a lot, and more wiring etc. Find a place to put it and so on. With glow all you do is tune it up and go. I have never had a glow plug go bad in flight. And they are cheap. Have had numerous problems with ignition systems over the years. I think it's just my bad luck. But EVERY ignition plane I have had either had an ignition box go bad or has had radio interference problems. And yes I followed all the proper procedures. Not one mag engine has ever given me problems. One plane with ignition even narrowed down to the engine itself. Every thing else in the plane was eliminated. And it took me 2 years to do it. I finally gave up on it and put in a Poulan on mag and never looked back, problem gone.
Another ignition plane would die every time I put it in the air with in a minute or less. But it would run till the tank was empty on the ground. I fought it for 2 years also figuring I must be overlooking something. I finally sent it back and got a replacement. That fixed it. For 2 years my Cub landed dead stick every flight. Never had to worry about refueling, it wouldn't run that long. Works good now though.
Another plane crashed on take off, not sure why, all I do know is the engine died. 25% scale Yak totaled. Sent the ignition box in to get the lead fixed and had to buy a whole new box, they said it can't be replaced on their model.
Have had a GP Giles 25% for several years now with a gasser in it. Last year when I put it away for the winter it was fine as always. This spring it suddenly has interference problems. Still does. I had it out today running it. Never flew of course. Now I have to try to figure this one out.
Not knocking any ones product. there are a lot of them out there working fine. Just letting ya know anything can cause problems. I just seem to be plauged with them.

Great reply Eagleflyer - you have brought to light many issues generally neglected by the so called serious modellers.
I have gone through a similar set of experiences - and so now when I go to the field, I put it a few models - The show model with the big engine and bold color scheme and 3D potential, The smaller fun model, with a glow engine and everyday 3D performance, The smaller electric with brushless and LIPO, and perhaps another one for slow puttering around.
At the field I assemble the big model first - for everyone to notice, I have arrived. But its the glow one which is first to fly. Many times the gas model is not even started - and when it is, everthing has to be perfect. No cluttered sky or noisy flight line, everyone anticipating almost another miracle - the biggie is about to fly now. HE is going to start the BIG one now. And thats what keeps me going, first sorting all sort of 'LITTLE' bugs, then swinging the prop hard over till arms feel like bags full of dead mice, pacing up and down the flight line doing a range check, and the list goes on
And then it finally flies - and when it does, everything falls silent - even the jet-skiers at the lakeshore stop and watch - it is just qualitatively different - the gasser beast.
So if you allow me, If you are flyer who wants to fly almost on a daily basis - stick with glow. If you are a flyer who needs to fly in order to live, and dont really mind some public attention at the cost of a LOT more work, go get some gas. OR, why not pack'em all together in your sunday picnic basket, glow-gas-electric and have a ball.

Cheerios
Sid

Sid you make it sound like Gas is harder to deal with than glow, really you are stating the difference between large complex models and small simple ones...there is a crossover point
of large glow v small gas

Gas can be simple...scale up a wot 4 and put a 35-50cc gas in it, believe me no dramatics needed

Thats correct crusty, you could do that. But any scaling up to accept a gasser increases the weight, which needs bigger servos, larger batteries, perhaps a powerbaord, more thorough checks and all in all deserves a lot more care. You are right, no need for dramatics at all, but the heavier gas powered models (even a giant stick with a direct bolt on weed whacker) have a lot more potential for dissaster. A few years ago we had a large 32 lb. model fly away while the modeller was standing just outside pit area adjusting an on-board camera at full throttle. Somehow the battery pack came loose and pulled out the connector, he panicked and wiggled the sticks while the model ran across the runway full throttle, got airborne in less distance than we had ever seen it do before, shot skyward, did a nice wingover before being smashed to smitherines on the pavement along the runway.
It was a sobering lesson for all of us.
I know, this could well have been a 40 sized trainer, and I have seen accidents with trainers as well, but the larger airplane deserves a lillte more respect, a lot more care and considerably more work to make them safe and enjoyable.
my 2 cents.

That's JettPilot. He just loves to put an extra pound of weight in his planes.

Bob

Yeah, I understand your point Sid, Ive even enjoyed the odd small electric and they gotta be the least troublesome way to go
I spent most of my modelling time so far on glow planes, then glow helicopters,...now I prefer petrol and dont find it hard to get a reasonably trouble free setup, but appreciate here is bit more to consider

Wow, there are a lot of old school guys here. Good gas engines (Electronic ignition, with auto advance) are far far more realiable, easer to start, better idle, smoother midrange, and longer lasting than any glow or maginito engine. Most of these engines have a life span at least 5 times that of a glow engine. They are much easer to start than a glow or maginito engine (will not kick back, and will easely hand start and you dont need a big spring, or have to wack or slap the prop)

Here is an example:

Brison 3.2, five years, 30+ gallons:
Dead sticks = 0
Hard starts = 0
replaced spark plug= 0
Adjusted needles = 0
Changed the switch = never
Replaced the ign battery once just because I thought it was getting old

Saito 180, 3 years about five gallons
Dead sticks 5-7
Hard starts, not with the starter, however kicked back several times throwing the prop, wasn't hurt
Replaced glow plug 3 or 4 times with type F
Adjusted needels 4 or 5 times a year
replaced berings once

ST 140, 5 years, 4 or 5 gallons
Dead sticks = too many to count
Hard starts, never
Adjust needles = every day of flight
Replaced carb & added fuel pump trying to get fewer dead sticks.
Replaced glow plugs= many, many times.

US 41, less than two gallons, sold
Hard starts, every time
Broken spring starter
no dead sticks
no needle adjustments

Hi Lee,

I'd like to add two other answers to your original question. First, in my own opinion and experiences, gas engines are less sensitive to mounting orientation than glow engines. For example, if a gas engine is mounted inverted in a war bird, I have found that the inverted mounting does not cause any issues with respect to how the engine runs or is tuned. I get the same nice, slow reliable idle regardless of the mounting orientation. I have found that four stroke glow engines mounted inverted are more difficult to tune for a sustained low idle and sometimes I have had to use a glow driver to get a nice, slow, reliable idle. Second, I have found that gas engines don't change how rich or lean they are running from the beginning to an end of a flight. Most of my glow engines would run leaner at the end of the flight than at the beginning. Not a big deal generally, but on some warbirds this would increase the idle to a point that was higher than I preferred, so I found myslef puting in a few clicks of down throttle trim at the end of each flight. I don't have to do this with gas engines.

Good luck in whatever choice you make!

-Ed

has eneyone ever trided to use gas in a glow engine? I have a Sato 180 on egnition system and I would like to run gas to get rid of the problems it causes with bearings. My engine is fully inclosed and is a real pain to get any after run oil in.