Ed

I'm gonna replace a worn out TT 1.20 glow engine with a 26cc gas engine.

Is this gonna be stronger or weaker then the 1.20 glow that's now in there ?

Would it be like maybe a 1.20 again, or maybe a 1.40, or 1.60 ? Or what ?

Thankyer kindly gents.

Ed

tkg

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MLD 28, stock, APC 17x8 8200+.
Zenoah G 20 aftermarket muffler, 8400 APC 16x8, tuned pipe APC 16x8 9000
What size prop did you use on your 1.20???
In the bigger planes folks are replacing OS 160s with 45CC gassers

Tired Old Man

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No hard and fast rule. The types of planes and flying styles are too diverse to make up a "standardized" size comparison chart. Does it go on a Cub or an Edge? Warbird or seaplane? Lazy Sunday flying or all out 3d and IMAC? The same wing area and weight will require different power levels based upon the airfoil, wing planform, and type of flight.

rmh

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Ed

On the same giant ugly stick airplane, I would convert from a 1.20 glow turning a 16x6 prop, to a 26cc gasser turning a 16x10 wide blade.

In your estimation, , will it fly faster or slower ?

rmh

The

busted blade

Here is a rough idea of what different pitch will do at different rpm and I doubt that the 26cc gasser will spin the 16x10 prop at even 6000rpm.

1. I estimated rpm between gas and glow (actuals will vary greatly)
2. Not sure how acurate Thrust HP is but is good for ideas only.
3. Everything is a factor when comparing and it should only be viewed as an approximation.

j_t01

First of all I am no expert on this but have done a couple of static tests on my 26cc stihl. With a 18x8 prop all I could get was 6200 rpm. second test was with a 16x8 at first was 7000 rpm. I then opened up the stock muffler with two 1/2" holes and got my target rpm of 7500. All test were done with wooded zinger props running gas glow mix. Hope this may help.

Jim

rmh

tkg

My Feedback: (1)

This thread is going in circles.
Input is needed to straighten it out.
OK we got a Ugly stick with a TT 120, turning a 16x6 at ?????
There is 1500 RPM varation in brands of "26cc" engines, what engine do you want to use, are you limited by weight, firewall size, or $$$
Fill in the blanks and you will get a lot more correct information./help.

AA5BY

I agree with TKG that more info is needed. Generally, IMHO when comparing glow to gas, one should keep weight factor in mind. It has been reported that a G26 would not provide unlimited vertical on an Ultra Stick Lite until after it was converted to electronic ignition saving six oz whereas the G20ei will provide unlimited with stock muffler. Obviously weight is the factor. The magneto version of the G26 weighs 1lb2oz more than the G20ei considering both can be balanced in the aircraft without additional weight. Obviously the extra power of the G26 magneto is not enough to overcome the weight difference when considering vertical performance. The G26ei saves 6oz.

An 18oz difference on a 1.20 size plane can't be trivialized when considering all around flying performance.

The G20ei will give long flights on 8oz of fuel, and I don't know the tank size requirement for a G26, but it may be 2-4 oz greater. If the big stick is less than 10lb 12oz auw, the G20 will yield unlimited vertical and might be a better replacement for a 1.20 glow.

In another report comparing the G20 to a MLD 28 in an advertised 1.20 size Yak but weighing 12+lbs, the MLD 28 was reported to be a far better performer. The MLD specs more prop but less weight than the G20.

rotccapt

just to give an example i have a 1/7 scale midwest super stearman that is powered with a zenoha g26 magneto version and an all up weight of 14 lbs. running 32:1 pump gas no ethanol and spinning an apc 17X8 i got 14 lbs of static thrust using a digital fish scale tied between the tail of my plane and a flag pole. in the air it has almost unlimited vertical it will go up several hundred feet and it was almost too small to see and it was still going. this plane was designed for a 90-120 size glow 4 stroke. hope this helps