I am a sportsman pattern flier who is tired of paying $14/gal for glo fuel and wiping off the gooey mess. It sure looks like the RCS 140 gasser will nicely replace my OS Surpass 120 with only a slight weight penalty. Any words of wisdom will be appreciated. The RCS 140 turns an APC 16X8 at 8800 RPM and gives over 15 pounds of static thrust (so they advertise). Thats a lot more than my 120 is doing.

The 140 - brokein -in on a pipe -is equal to a 1.20 YS setup right -
in a 9-10 lb model -it does work very well - we have used one in one of our EXCESS models
You must not build a heavy large model for best performance - about 900-1000 squares tops
I made three gas pattern models using the ZDZ40 - these are at 11 lbs - incredible power-1280 sq inches .

Hi Dick,

Have you posted or taken any more pictures of the Petrol or the newer (improved) design you had previously posted about? I am saving up for a ZDZ 40-50 just incase you make a run of planes....:>)
The gas power seems the way to go. No fuss, no muss, low cost of the fuel, and RELIABILITY! I hope we see a lot more of them.

Regards
Bill

hope you don't mind me posting a picture of the Petrol.

Hi Dick, could you list gas engines that are equivalent to 90, 120, 140, and 160 two-stroke glow engines. Hope this is not asking too much. Thanks !

Not exactly gass.. but I have seen a Webra 1.20 powered 2x2 with a Davis Desiel head conversion.
It was very, very powerfull!!! and quiet to boot!

There used to be a story going around about a well known(ish) pilot who sponsors threatened to pull out if he didn't stop playing around with his DD converted engine.

Forgive me if this is a silly question, but is a 40cc gas engine legal for competition? (I have no idea of rules or restrictions)

If not, I guess these would make a really good practice plane,
if you do alot of flying that is.

Any size gas or glo engine is legal for pattern so long as wingspan is 2M or less and weight is 11lbs or less.

I wonder if we will see a new breed of lightweight gassers for the pattern and FG1 scene?

Or are engines like the ZDZ 40 already as light as reasonably possible?

Other than the weight, what are the other downsides to a gasser as compared to a glow motor? (ie ys dz140, os140,etc)

I think that the day that 40cc gassers are used, is when there will be a 40CC YS, because yes, they will still sell sell thousands.

Downside?
weight -
other than that - smoother running -especially at idle --
less fuel costs - huge difference-
no goof ball fuel induction system like the fool injection now being fobbed off as necessary .
I have been runing a 40 powered pattern plane all fall now and the engine has never once killed even at lowest idles - and power is way overkill- if the engine were say - 80% of what it is -weight/power -etc -it would be perfect for the present models.
I never had problems with the glow -I figured out what they needed -did it and away we went - BUT the cost of operation simply became a big sore point with me - $15.00 a day !
Now it actually costs more to drive the 30 mile round trip than fly all afternoon And the engine maintenance costs are ZERO No plug problems - no rebuild s - Am I sold ? absolutely .

Yes I understand exactly what you are saying Dick, I only run a couple of .46 size planes at the moment, and my pocket is already hurting from the cost of fuel. ( I have a strip at my house and fly alot).

And I have been wondering how I could ever afford to opperate a ys 140 dz powered plane? Other than the astronomical upfront cost of this type of plane, the fuel bill would be outrageous, especially with all that nitro.

Sounds to me like a gasser is the way to go for me in the near future.
Lots of practice for not alot of dough.

What type of oil is commonly run in these gassers?

Robert , a 40cc ys !!!!!!!!!! That would be scary!!!!!!!!!!
Youd have to have a 44 gallon drum of fuel in your flight box!!!!!!
hehe.

oil any good synthetic- the AMSOIL which many flyers use is quite inexpensive.
A gallon of fuel mixed up is under 3bucks
One gallon of gasoline -- 3 ozs of oil
128 ozs in a quart
so figure 60cents for oil and 1.50 for the gasoline = $2.10
Even if gasoline doubles and oil doubles - that's 4.20- as a goofy example.
My 40 CC ZDZRE pulls a special 20x10 prop - on a pipe in the mid 6000 range - (an ordinary 20x10 - in the 7000 range)
and I can fly for 11 min on about 12 ozs of fuel - I am throttled waaay back a lot .
Power is only added on uplines
On stuff like double vertical snaps - I use full power and the plane actually accelerates out of them.
Again - why would I want to go back---

Dick, thanks for your input. Just curious, what is the cost of a 40cc zdzre? What does it weigh? Who sells them? Thanks again for your input.

In the USA RCShowcase - their ads are on the Universe -look at a few headers
above various pages on engines etc..

Just now I read in the APA (Australian Pattern Association) newsletter, that a proposal to remove weight resrictions to allow the use of Gasoline engines, may have been put forward at the 2002 European Championships.

This is because- "apparently Methanol is a problem in some influential areas".

There was also talk of scraping the noise restrictions altogether.

Apparently though, even if these proposals are accepted, they can not be implemented for at least 2 years.

But at least there is thought to accomodate these engines, even if it is for reasons other than simply running costs.

Frankly --I see it as a necessary move .
Nitro fuels are simply too expensive for most of the world.
The gasoline engines are still -in many cases - quite undertuned.
Ignitions are now appearing on the market - far in advance, design wise, of the ignition units so common in the USA for a number of years.
This doesn't mean that they are superior for most current applications
But - they can be programmed into curves for responses desired -- tachs can be "built in". and I really expect to see some miniaturization happening fairly soon.
We tried a nice little setup made from very current bits -- where we had the coil mounted on the engine and the electronics literally suspended in a wire to the coil.
It worked quite well.
Al Diem made and assembled it for me.
If we had some better quality miniature spark plugs - then we would be in even better shape.
I am speaking of plugs , the same size as glow plugs -- not the 12mm
An alky and oil engine on spark works very well but current carbs are really not commonly available for this arrangement.
As gasoline and oil tho I expect to see the switch from 1.5 and larger glow - to go to gas - at an increased rate.
Any bets as to when the FAI does shift?

Dick, I am SERIOUSLY considering taking up Pattern full-time again (means actually practicing and going to meets), all this talk of cheap gas pattern is really intriguing me. I know the forum went round and round before with .60 size pattern and whatnot, and I was heavily leaning that way. But, the 2 meter ships fly so darned well! But, I'm reluctant to begin feeding the YS monster again. Not to mention $120 digital servos, etc.

Would a neat 2M ship like a Focus or something work well with your ZDZ40, or the RCS 1.4, or ??? Pattern season is almost upon us, and I know I could get something together quickly enough, and start getting some flying in before the meets crank up. I don't need an ARF, but obviously time is coming up on me quickly, so would need a quick build kit, or something...

I guess I'm looking for some serious opinions on what will work.


Thanks,
Phil in Austin

The Focus or other ARF/ARC planes are unlikely candidates for gas because of the fixed wing location. I've not seen a gas setup for pattern at less than 40+ oz, which means the wing needs to be located forward, relative to glow power, to balance the engine. If the wing isn't moved you have to add weight to the rear to balance for CG to accomodate the substantial weigh you've added to the front.

You could use gas with a kit type plane, just make sure that the kit is capable of building out to a light airframe and again, that you move the wing forward. I've got a hunch that our Temptation kit could work for gas, though no one has indicated to me that they're trying it.

However, to some extent I have to question the actual cost saving amounts people are using. I guess some still buy fuel by the gallon, but if you're a pattern flyer, practicing on a regular basis, I would think you've figured out some kind of deal. Personally, I use 15%/17% Red Max with the Webra (cheaper than their sport fuel because of the lower oil content). I go in with a friend and buy a barrel. It ends up costing around $7.25/gal. True, not as cheap as gas, but hardly a prohibitive expense.

With a great deal of respect for Lee I beg to differ. The Focus is ideal for ZDZ40 with the ignition module as far back as plug wire will allow and ignition battery on wing tube. Also using 2 368 digital servos for elevator 1 9411 on rudder in the tail. Receiver and battery at rear of wing. Balance seems to be very close at this stage.

It will be 1lb heavier flying weight so it needs 125 more sq in of wing area.

I have Focus wing 899 sq in and a EMC wing 1012 sq to test on this set up. do not know the airfoils used on the 2 wings or if there is much difference.

I have 1 week till am finished with dreaded Tax return then will finish testing pipe setup. I hope to have this finished and flying in about 3 weeks.

Good luck with the Focus/gas experiment! You're fine on wing area as long as you're within the 11 lb legal weight limit.