In looking at specs for a number of 20 to 30 cc gas engines to replace my 1.2 4 stroke ($300 + replacement cost) I have determined that the Zenoah G-26 has the best bang for the buck. It turns a 16 x 8 at 8900, my 1.2 4 stroke turns a 15 x 8 at 9300. I realize the G-26 weighs a pound more, but I can use a much smaller fuel load on board the plane. Any comments on this conclusion please?

Check it out at rcshowcase.com
Mine was turning a 17-8 at 9000 before I crashed it and broke the crankshaft.

A G26 turns a Mejzlik 18-6 at 9000 without the muffler, pulls 17.5 lbs on a spring scale, flies 30 minutes on 20 oz of gas....
Verified on a extended wingspan Joss Stick flying in Phoenix, AZ....

with a muffer and about 4 gallons i am getting 83-8500rpm on a rcs 1.4 gasser.

I'd say the RCS140 also but do you realize your looking alot more weight even with a smaller tank? Sometimes a gasser just isn't worth the weight. Remeber you balance most airplanes with an empty tank so while it might have the same weight wet it'll be heavier dry and you balance it dry.

I sure would love to see ACTUAL weights of RCS 1.40/8oz and OS 1.20 Four stroke/16oz tank and see how they match up. Or is that too big of a tank for the 1.20?? Not sure cause I don't like feeding anything bigger than .47 glow.

Would have to include mufflers, prop, and ignition/battery (on the RCS)....

The big savings just comes in the cost of feeding....

High Flights!
CrazyHerb

One thing were missing here is cost. As I see it, the RCS 140 is $345 without muffler and a muffler is at least $50. The G26 comes complete for $299. That is a $100 difference. I am looking hard at the RCS 140 but I also want to buy a new radio.

I'd say buy the radio you want and stick with the 120 4 stroker... save the gasser for your next project in the 40-50cc range.

Take a look at www.gcbmrc.com . Worth a look @ only $210.00 plus shipping, weighs the same as the G26

the rcs 1.4 really is not a heavy motor it still requires a motor mount and muffler like most motors off course you have to run a battery on the ing also. i have mine on a funtana and that baby would have been tail heavy w/o the int battery. in that case i would have had lets say an os-160 on there and running about the same weight less the int battery but now 4-5 oz on the nose with lead to acheive balance. Of course the os-160 would smoke the plane in comparsion to power. yes 8 oz will last a very very long time on the rcs 1.4 sipping the go go juice. My 1.4 will torque roll the plane and pull out of a hover very slow and steady, its not overpowered by any means. I treat the funtana as a fun fly and i keep her in very close and fly moves like rolling elevator/harrier, elevator, t-rolls. i weighed mine at 3 lbs with the motor on a mount with the muffer attached. On some motors with a mount this weight can be beat but again on others once you put that muffler on there along with a mount you are right were the rcs is located......

Go with the RCS 140.
After this motor I am selling all my glo motors.

I just weighed my RCS 140. 2.5 lbs with RCS pitts muffler,C&H ignition and 700 mah battery pack.

WreckRman2,
Are you saying the power to weight ratio is poor until you get to the larger gas engines? I have had bad luck with 4 strokes, the two I have had were so finicky and a pain to maintain. I know other people say the have not had a problem. I can replace the 1.2 FS with a much cheaper good motor like an ST 90 that will pull my 8 lb plane around just fine. I just wanted to try the convience, lack of mess and lower cost of gas.

boy - none of these comparisons are apples to apples -
first off - the 1.2 OS weighs about 30 ozs- and is one helluva good glow engine -
the YS weighs a bit more - is more expensive but more power

The closest in weight and power is the RCS1.40 -and on a pipe is equal to the 1.2 OS and YS (on a 16x8 prop ) cost is also highest.
The new Zenoah -if you don't mind the side carb and clunky muffler and muffler (?) is a bargain.
For many sport flyers and that is where a lot of flying is done - the Z26 is probably the best buy .
But if you are retrofitting a pattern model and like the smooth cowled in look - the RCS is my choice-
We helped a friend setup one on a 10 lb EXCESS and it is a perfect setup -as a pattern model.
quiet , powerful, cheap to feed.

I use Saito and have never had a problem with them. If I could afford it all my smaller planes would run Saito's.

As for power to weight the glow motors will put out motor power for the same displacement however by the time you include engine, muffler, extra battery and switch the weight really adds up fast for a gasser. Don't get me wrong I love my gasser but I wouldn't try to use gas on anything smaller than a 40cc unless I just wanted something to putt around in the sky.

I've heard great things about the RCS140 and if I were to try a small gasser I would buy that over a Zenoah any day. I've heard it will pull a 10-12 lb airplane easy but if the wing loading is so high you loose performance you won't be happy.

The engine weight to power crossover etc---seems to be at 40 cc--
as for the glow stuff over a 1.2- they just are to hungry for my tastes anymore.
my favorite gasser so far is the lowly ZDZ60 - with a RCS can on a very short header .
extremely quiet and turns a MenzS 24x10 at 6200 here and the Mejzlic 24x10 at 6500.
extremely smooth - cheap - etc.
the 40 RE ZDZ is my "pattern plane" engine- it will all fit in a 3" wide cowl - if req'd - very strong - and on a pipe very quiet -
It looks like other manufacturers are now getting on board the rear induction bandwagon - so we will probably see even more higher performance, light weight gas stuff.
The winner this time is -- the customers!

Check your e-mail Richardfast!

Weed Wacker motors are by far the cheapest and no ignition battery is needed. Very reliable and if you trim them down there ain't much weight to them either!

Regards,
Bryan

had OS 120 in 4* 120 with nose weight,changed to RCS 140 and removed weight,plane flies at same weight,more performance,cleaner,and the price of fuel is a very nice change,around 28 minutes on a 26 oz. tank of fuel.

When you compare glow engines to gassers, be sure to include the motor mount and/or muffler in your overall weight. You'll find that the typical 1.20 FS glow + motor mount weigh around 36-42 Oz. Backplate mounted gasser like the G23/G26 don't need a motor mount and may end up weighing only 10 Oz. more overall.

Considering the fact that you'll carry less fuel and the tank can be move off the nose to over the CG, the weigh "penalty" may be trivial at best.

Does anyone have rpm reading and what prop?
Also what muffler were using.

with a muffer and about 4 gallons i am getting 83-8500rpm on a rcs 1.4 gasser.

http://members.cox.net/krayzc/

RCS 140 with 3 gallons of fuel through it (just switched to Amsoil 50:1), and the following props:

APC: 16x8 9100 rpms
APC : 17x6 9000 rpms
Mejzlik: 18x6 8600 rpms

sea157,
How are your flights going? Is it fun? Those are great numbers!

Joe

sea157
those are great number i suppose i need to get ready to adjust my needles so i can get all of the getting while the getting is good.

sea157
are you using the pitts muffler i better make sure we have the same set up he he.........