Starting a G-Mark .03

Is that the stock prop?
Best peak hit 16,876 rpm
I see the yellow feed line goes up out the original hole in the fuselage?


If stock prop here is my data on that prop:
G-Mark .030
Stock prop: 115M x 50M  / 4.53 x 1.97
Static 17,280 Best Peak / 5.64oz thrust / .062hp / 46.3W / 32mph

Silicon fuel line size:
Outside diameter: 3.5 mm
Inside diameter: 2 mm

Mauricio, that G-Mark .03 is a real performer in that plane, excellent work. It is definitely not underpowered, really steps out.
You definitely have a little pocket rocket.

Behold a G-Mark .03 Hummingbird engine flying on a plane!!!! Bravo Mauricio!!!!

 

Congratulations Mauricio!

Thanks guys! ... I'm glad to know that you like the result.
Place the video without comments so that you can see and define your own conclusion regarding this recent project.
In my little experience with G-Mark .03 since it is the first engine that I use of this brand, I think it is another work of art for its time.
Its operation is good and if you take into account all the extra parts such as exhaust gases, and its r / c carburetor, they complement a great engineering work behind this piece.
From my point of view, I would only have it come from the factory with a pressurizer in its exhaust and with cooling fins in its glow plug, in order (in my opinion) to improve the performance of the engine.
I believe that if you have a G-Mark .03, you have an important part of the history of this Hobby-sport and that it deserves to be recognized as a good element to match other outstanding brands of the time.
I am happy with the result and even happier to share all this with you, who are already part of my friends. Sincerely, Mauricio.-

This is a rare vid as it shows what the engine can do unloaded with cool air flow.

Cox Prop 4.5x2 Results from both vids best peak readings from RPM Gauge:
GM 17,622 static / 20,994 unloaded
TD 17,199 static / 22,771 level / 23,498 dive pass.

The TD static reading could have been better but you did not hold full throttle
long enough for the engine to reach it's full potential peak. The iron piston in
the GM engine and it's porting just will not allow it to make the power of a TD.
What you do get is a muffler to help direct the oil without it spraying all over the
plane, a major plus!

I think with a turbo plug and extra cooling fins along with drilling out the carb
barrel to it's max diameter within the throat of the venturi will improve rpm.
Another step would be to polish the bypass ports and cranks fuel / air passage.
Next mill the piston like a cox killer bee where the lower half of the piston skirt
is thinner on the inside walls to reduce weight. I think the engine could gain
up to 2.5k unloaded with these efforts. Then again the same could be done to
the TD engine. KILLER TD .020! You could also wick a fuel channel on the back
side of the flywheel to increase charge pressure / flow up through the bypass ports.
CNC crank case with bearings for both engines vroom vroom  

You have did it Again my friend !! The plane looked very stable in flight for to bee so small and the engine run was great !! You got to love it when landing and engine still idling, Glad to see you got the tank figured out the flat seems to do the job, Nice fling too

getback wrote:You have did it Again my friend !! The plane looked very stable in flight for to bee so small and the engine run was great !! You got to love it when landing and engine still idling, Glad to see you got the tank figured out the flat seems to do the job, Nice fling too  

My dear friend Eric !!! (I'm still waiting for you to visit me and have good pizzas !!) ... thanks for your comment!
It was also possible, because of your encouragement, to find a way to solve the deposit problem and I did so !!
Thanks friend for your support !! ... Remember, the pizzas wait for you!

1/2A Nut wrote:This is a rare vid as it shows what the engine can do unloaded with cool air flow.

Cox Prop 4.5x2 Results from both vids best peak readings from RPM Gauge:
GM 17,622 static / 20,994 unloaded
TD 17,199 static / 22,771 level / 23,498 dive pass.

The TD static reading could have been better but you did not hold full throttle
long enough for the engine to reach it's full potential peak. The iron piston in
the GM engine and it's porting just will not allow it to make the power of a TD.
What you do get is a muffler to help direct the oil without it spraying all over the
plane, a major plus!

I think with a turbo plug and extra cooling fins along with drilling out the carb
barrel to it's max diameter within the throat of the venturi will improve rpm.
Another step would be to polish the bypass ports and cranks fuel / air passage.
Next mill the piston like a cox killer bee where the lower half of the piston skirt
is thinner on the inside walls to reduce weight. I think the engine could gain
up to 2.5k unloaded with these efforts. Then again the same could be done to
the TD engine. KILLER TD .020! You could also wick a fuel channel on the back
side of the flywheel to increase charge pressure / flow up through the bypass ports.
CNC crank case with bearings for both engines vroom vroom  

Friend Brad ... thanks for all this contribution ... if you come with Eric, we eat some pizzas and try to make all those reforms !!!

Well, here I made a video in "static" ... I do not intend to generate polemic, each engine has its benefits, and I love each of them, so, I just try to show what is under the same circumstances for each one.
I hope you enjoy the video, as it happens to me, while I enjoy a good beer !!

Resolution at 240P is not clear enough to read the tach.
You use to post at 480P which is readable.

Thank you for sharing - after warm up saw a peaks:
- 17,280 rpm / TD .020
- 18,249 rpm / GM .030

The more the GM runs the more it breaks in.
It just can't unload like the TD in the air.

   

Nice running engine and excellent flying. That flying vid captures what the .03 can do.