I am looking for a gas engine to put into a 60" bipe that should come out around 10lbs with out engine. This plane use to fly with a Webra 120 (30oz with muffler) but did not have the power to fly out of a hover though it could do just about everything else. I know the g-23 and the 3w-24 does not have the vertical that I am looking for so:

My question is what is available?

Is 40cc's to much? That is really the next level. The only 30cc I've seen is the RCS 1.8. Would that be enough?

Suggestions.

Which Bipe do you have?

What type prop, size and rpm was the Webra turning. I'd compare the numbers to reported numbers of other engines. You will indeed end up with a heavier model with a gasser. I'd suggest your looking at close to an additional lb. dependent on what engine package you choose, maybe even more.

If the plane is 10lbs. I'd be surprised if the 3W 24 would not do what your looking for...

The plane is a Cermark Pitts. And before anyone flames the plane I am very happy with it.

I flew it for two years with the webra and tried a lot of different props from 14-8 to 16-8 and even an 18-4. Tried wood, carbon fiber and nylon.

I have no complaints about the Webra other that the mess and that I could not get the "pull" I wanted.

Since I have not flow it for a couple of seasons and sold the Webra I'm stripping down the plane and will be recovering it. So if I need to beef it up alittle to put a gasser in it now is the time. I just want to get away from glow engines.

Any recommendations?

Two different charts, rcfaq and ThrustHp

Webra 120, 18-6 MA prop, 9100 rpm from rcfaq, 25.3 thrust from ThrustHp chart
RCS 1.8, 20-8 prop, 6800 rpm from RCS,21+ thrust from same chart
Something wrong with this picture.....
And the RCS is heavier than the Webra....

If you want a gas engine that will provide more pull than your Webra 1.20 provided, you'll have to move up to around 40cc in displacement. The ZDZ 40 (not the reed engine) would be my first choice.

Thanks for the info.

I had seen a lot of postings of people putting this size engine on a several 120 size planes.

I have the ISC Pitts II which is not that much bigger (64"ws vs 60"ws) and it uses a 4.0+ engine. I figured the RCS might not be the right choice.

I'm glad I stripping it down so I can beef up some of the structure to handle the gas engine.

THX's for you help.

Unfortunately, I think that u wil not find a gasser for this plane that will both out perform the Webra AND maintain a reasonable weight for this airframe.

Fortunately , there are many 120 size glow engines that are more powerful than the Webra, Infact the Webra is one of the weaker 120's available and yes , I have owned the Webra, and can tell u that the Thunder Tiger 120 , and Saito 150 (which I have also owned) are far more powerful.

I would also recommend the Moki 1.35 and I am sure that there r others.

I have flown the Cermark pitts with the Saito 150 combo and it is very impressive.

I've also owned a ZDZ 40 and IMO, it is WAY too much power and vibration for the Pitts to take.

Best gasser would be the RCS 1.4 but, only expect the same power out put of your Webra unless you're willing to hang a tuned exhaust under the aircraft.

Sincerely,

Mike

DK jens on this site had a cermark pitts with a saito 1.80 hover at 1/2 throttle flew great...........

Just want to put in my plug for the 3W24! I fly a couple of them and THEY ARE NOT comparable to the G23. I've got them swinging 18 X 10 props at 6,900, or just a coupla hundred shy of what a G38 will do. And they weigh almost 2 lbs less than the G38.

On a 10 lb plane, you should get plenty of vertical with a 3W24.

RC Report did a good review several years ago, if you'd like to see how well they swing different props.

My only criticism is that they're considerably louder than the G23.

mt

If only we could get the Europeans to drop those multi-bolt hubs and revert to the traditional single threaded shaft with a single nut. The multi-bolt hubs represent unnecessary extra work with no practical advantage. More work is not appreciated by this OF.

Thrust charts are fine, but 9100 with and 18-6 on a Webra. Sure.......

My webra flew best on a 16-8 APC turning 8800 and according to ThrustHP that is 14.79 lbs of thrust. This was on 10% nitro. We tried 15% 20% and the engine was never reliable. I was told this was because this engine was made for the European Market and as such was not designed for high nitro content. Whether it is or not I do not know. I loved the engine for its ease of start and reliability and would buy another in the future. But the reality was that "the motor I had" never pulled the Pitts very well in the up lines.

How about the RCS 1.8? Are the numbers that they list on rcfraq and on the rcshowcase real? If so this might be the engine and its a gas burner. What would be a good three blade if ground clearance is and issue?

One thing i can tell you i have researched and looked in to the moki 30cc and i can tell you now there would be no slouch in power for your 60" Biplane. The moki engines are incredibly compact and very light.
And there not all that exspencive you can get one from germany without paying import tax (persuming you live in the uk)

WARNING WARNING!! DO NOT GO NEAR ZENOAH, THEY ARE FAR TO HEAVY AND THEY ONLY HAVE HALF THE POWER AS OTHER MODELS OF THE SAME SIZE.

Another Typical Zenoah basher...Yo Paddy..Get your head out of wherever it is and look around..My new ZENOAH G260PU 25.4cc weighs 3 lbs, INCLUDING the muffler, ignition, and battery...Turns 9000 rpm with a Zinger 18-6..At 7000 feet..
Show me what's lighter and has twice the power ...
I just ran a 3W 24 this morning..18-6 prop, 8400 rpm...18-8 prop, 6900 rpm....
Have you even SEEN a G26 ??????

RS Allen...I SAID the chart was wrong, it's just for comparing...FWIW..the same chart shows 25 lbs for a G260 with an [email protected] WILL do this, and at 9000 feet...
More than the RCS, but slower plane speed......

rcign:

My apologies if I misread you post. To me it seem to indicate that the webra should have be doing more.

Friends?

Yup...I thought the chart looked too high, too..It shows 9800(?) with a tuned pipe.....

RCIGN, is the g-26 you are refering to one of your glow conversions I have read about on your other posts?

Nope..The old style turned 8200 on glow, 7200 gas.. the g26 is 9000 on gas, same exact prop...Haven't tried the G26 on glow yet, I don't think Zenoah does that...Will try my next 26 on glow...Should be really interesting....

Horizon's web site claims up to 8900rpm on the g-26 , this is only marginally better than the Webra 120 , if at all, and the weight claim is 53oz, that makes it as heavy as the some of the 40cc-50cc gassers. Pls don't get me wrong, I'm not saying it's not a good engine, just not ideal for the Cermark Pitts.


Also Rcign, U mention a battery with the Zenoah, did u convert it to electronic igniton?

Mike

Maybe my 3 lb (that's 48 oz with ignition, muffler, and battery) G26 is an aberration...Or my TNC tach is wrong ..Or my Zinger 18-6 prop is not 18-6..Ordered a Mejzlik 18-6 from Dave at DA yesterday, should have it tomorrow...
Taking off the source coil and mag rotor saves weight, and replacing the stock muffler with an Abell muffler gets 600 more rpm and less weight....

rcign, when will you be selling your version of the 26? I believe you and want one!!!

Check your PM

i hate that i wanna know what he said!!!!!!!!!! lol

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