[Guest]

i have 2 1/5 scale planes a cub and a 182 .
i have a os 91 4 stroke in the cub.im considering going with gas for both.
doing the math with engine size i figure a 20cc with do the job.
what i want to know is there a physical size differance between a 20cc and a 26cc gas engine? or is a 26 just a punched out 20?
i also notice that rear carb gas engines seem to put out a lot more hp than there side mount counterparts,though this can be a big issue if you have limited space under the cowl .(meaning rear mount carbs make the engine that much longer).

thoughts and comments please.

[Redbaron]

If money is not a restriction, then Saito make some beautiful 4 stroke gassers. The Evoultion GT26 would be another option & very easy to install with its beam mount. I have an Evo 26 & it is a great engine, very user friendly. The extra power of the GT26 would not bother either of those planes. Hope this helps.

[Nev]

If price is a factor talk to Raymond at PRC about his V2 26cc CRRC. or his new SV line....you can get almost two for the price of 1 Evolution. Granted they are not the same animals but may work for you as they do for many others in scale planes. Good luck.

SV line
http://www.prcmodel.com/modeng/name/...re/category/48

V2 26cc CRRC
http://www.prcmodel.com/modeng/name/...od/product/305

[Guest]

thx for the info guys
here are some info i was working on.

O.S. FS-91 II Surpass 4-Stroke
Power Output: 1.6 BHP at 11,000 RPM
Weight-With Muffler: 24.2oz (1.5 lbs)
.93 lbs per hp

Fuji Imvac BT-24A 23.9cc Gas Engine
Output: 2.2 bhp @ 10,000 RPM
Weight: 3.43 lbs (1,557 g) with muffler
1.55 lbs per hp

so a difference of 1.93 lbs and only a gain of .6 bhp seems hardly worth it weight wise.
it would seem the real advantage of going gas would be price, the cost of fuel and ease of
maintenance.

now if you were to take a CRRC GF26i gasoline Engine compared to the os 91 here is what you get.

CRRC GF26i gasoline Engine

Dry Weight: 1.165kg/2.56lbs. (With standoffs, muffler and CDI)
Maximum Output: 2.42 hps/7200rpm or
1.05 lbs per hp

O.S. FS-91 II Surpass 4-Stroke
Power Output: 1.6 BHP at 11,000 RPM
Weight-With Muffler: 24.2oz (1.5 lbs)

O.S. 110FS-a Ringed 4-Stroke
Power Output: 1.8 hp / 10,000 RPM
Weight: 19.2oz (600g)
Muffler Weight: 2.3oz (72g) total weight with muffler 21.5oz = 1.34 lbs
a .7lbs per hp so far that's the best power to weight ratio



now i know i,m comparing apples to oranges but it also boils down to weight to power.the heaver the engine the faster one has to fly to sustain flight

[RCplanman]

Goundcrew, You might want to look at AEROVATE RC. They are in NIG. FALLS,US.
HENRY, has both a 20&28CC rear carb. that might answer some of your desires.

[Gary Maker]

I have 2 of the CRRC Pro gf26cc gas engines, both are/will be in 1/4 scale WW1 aircraft. From all the research I've done on these engines, so far, everyone who ownes one is very happy with the performance....relyable running, good throttle transisition & lots of power for the application.

I purchased my first one directly from the company and with the upgraded electronic ignition, tax and delivery, I paid $260 delivered to my door. Can't beat the price!

I love four stroke engines but you just can't beat the overall cost savings both in purchase price and running of gassers.