Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» Medallion .049
by GallopingGhostler Today at 11:29 am

» Question re. Helldiver fuel tank
by Cox International Today at 10:49 am

» ebay Cox Mercedes, rough.....but check out that glow head.
by rsv1cox Today at 10:43 am

» Brodak 1/2A Flite Streak getting busy
by Ken Cook Today at 4:27 am

» cox recoil cord
by 944_Jim Yesterday at 8:43 pm

» Diy tanks in MS
by Ken Cook Yesterday at 7:51 pm

» Cameron .19 Marine Engine
by Ken Cook Yesterday at 7:45 pm

» treaded rod 5-40
by 944_Jim Yesterday at 6:26 pm

» CEF Honors All Who Served
by GallopingGhostler Yesterday at 5:18 pm

» Off topic - Tire pressure monitoring system
by GallopingGhostler Yesterday at 4:57 pm

Cox Engine of The Month
October-2018
Mudhen's

"Prototype T.D. .010 c.1960"



PAST WINNERS
Speed Contest 2018
CEF Traveling Engine

Win This Engine!
The Traveling Prop
Gallery


World of Aviation

Starting a G-Mark .03

Page 4 of 4 Previous  1, 2, 3, 4

Go down

Re: Starting a G-Mark .03

Post  1/2A Nut on Sun Oct 28, 2018 8:27 pm

Also be careful of fuel line size and aluminum tube size going into the tank.
Too big of a straw will cause fuel draw issues, get a small diameter straw and
a larger dia. straw draw in a drink with them you can tell just how much more
work it takes to get the drink.

RC Plane
avatar
1/2A Nut
Diamond Member
Diamond Member

Posts : 1976
Join date : 2013-10-20
Age : 55
Location : Brad in Texas

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  MauricioB on Sun Oct 28, 2018 10:41 pm

Well my friends, thanks to ALL for collaborating with their opinions and information, this is the best configuration I have achieved. Remember that I do not have much space in the model, it would be ideal to put it 10 mm higher to the fuel tank, but, there is no physical space to do it, so ... from 1 to 10 ... I think I'm in an 7.55!! , the engine works, and I think I'm going to leave ... I let you give your opinion ...
Hugs! ... Mauricio.-

Before:


Now:


So:
avatar
MauricioB
Diamond Member
Diamond Member

Posts : 1772
Join date : 2016-02-16
Age : 47

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  1/2A Nut on Sun Oct 28, 2018 11:16 pm

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
avatar
1/2A Nut
Diamond Member
Diamond Member

Posts : 1976
Join date : 2013-10-20
Age : 55
Location : Brad in Texas

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  MauricioB on Mon Oct 29, 2018 9:10 pm

avatar
MauricioB
Diamond Member
Diamond Member

Posts : 1772
Join date : 2016-02-16
Age : 47

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  GallopingGhostler on Mon Oct 29, 2018 11:01 pm

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. cheers Thumbs Up Beer Cheers
avatar
GallopingGhostler
Diamond Member
Diamond Member

Posts : 1713
Join date : 2013-07-13
Age : 64
Location : Clovis, New Mexico

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  1/2A Nut on Tue Oct 30, 2018 12:20 am

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

Thumbs Up  RC Plane Thumbs Up
avatar
1/2A Nut
Diamond Member
Diamond Member

Posts : 1976
Join date : 2013-10-20
Age : 55
Location : Brad in Texas

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  balogh on Tue Oct 30, 2018 2:38 am

Congratulations Mauricio!
avatar
balogh
Diamond Member
Diamond Member

Posts : 1974
Join date : 2011-11-06
Age : 60
Location : Budapest

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  MauricioB on Tue Oct 30, 2018 4:48 am

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.-


avatar
MauricioB
Diamond Member
Diamond Member

Posts : 1772
Join date : 2016-02-16
Age : 47

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  1/2A Nut on Tue Oct 30, 2018 5:06 am

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  Cool



Very Happy RC Plane Very Happy


Last edited by 1/2A Nut on Tue Oct 30, 2018 10:18 am; edited 1 time in total
avatar
1/2A Nut
Diamond Member
Diamond Member

Posts : 1976
Join date : 2013-10-20
Age : 55
Location : Brad in Texas

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  getback on Tue Oct 30, 2018 9:25 am

You have did it Again my friend !! Clapping Clapping Clapping Beer Cheers 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 Smile sunny
avatar
getback
Top Poster
Top Poster

Posts : 5065
Join date : 2013-01-18
Age : 61
Location : julian

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  MauricioB on Tue Oct 30, 2018 9:39 pm

getback wrote:You have did it Again my friend !! Clapping Clapping Clapping Beer Cheers 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 Smile sunny  

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!


Last edited by MauricioB on Tue Oct 30, 2018 11:12 pm; edited 1 time in total
avatar
MauricioB
Diamond Member
Diamond Member

Posts : 1772
Join date : 2016-02-16
Age : 47

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  MauricioB on Tue Oct 30, 2018 9:45 pm

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  Cool



Very Happy RC Plane Very Happy

Friend Brad ... thanks for all this contribution ... if you come with Eric, we eat some pizzas and try to make all those reforms !!! Very Happy Thumbs Up Beer Cheers
avatar
MauricioB
Diamond Member
Diamond Member

Posts : 1772
Join date : 2016-02-16
Age : 47

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  MauricioB on Tue Oct 30, 2018 9:48 pm

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 !!
avatar
MauricioB
Diamond Member
Diamond Member

Posts : 1772
Join date : 2016-02-16
Age : 47

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  1/2A Nut on Tue Oct 30, 2018 11:18 pm

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: Thumbs Up
- 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.

Beer Cheers   Airplane  sunny
avatar
1/2A Nut
Diamond Member
Diamond Member

Posts : 1976
Join date : 2013-10-20
Age : 55
Location : Brad in Texas

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  Jason_WI on Tue Oct 30, 2018 11:31 pm

Nice running engine and excellent flying. That flying vid captures what the .03 can do.
avatar
Jason_WI
Diamond Member
Diamond Member

I Support My Forum

Posts : 2313
Join date : 2011-10-09
Age : 43
Location : Neenah, WI

View user profile

Back to top Go down

Re: Starting a G-Mark .03

Post  Sponsored content


Sponsored content


Back to top Go down

Page 4 of 4 Previous  1, 2, 3, 4

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum