Glow Plug for the G-Mark 03

Congratulations !!!!

I don't know you never received the KB crank so I will always
be concerned about shipping to your country, I hope the engine
makes it there safe. Check your PM box I sent you a better photo
of the customs ticket.

I think Kris has a good solution so you can enjoy years of flying with
the engine.

1/2A Nut wrote:Congratulations !!!!

I don't know you never received the KB crank so I will always
be concerned about shipping to your country, I hope the engine
makes it there safe. Check your PM box I sent you a better photo
of the customs ticket.

I think Kris has a good solution so you can enjoy years of flying with
the engine.

Thanks Brad!
Thank you also for taking the time and taking another picture of your shipment. I still do not have news ... (it's already too long)
What I do now is hire a service, they buy for me and bring the products to me. I do not buy directly, this service does it for me and I make sure that things get to me.
If I had known before, I would have told you to send the crank to your MIAMI address and they would bring it to me from there, maybe at another time and if you would sell me something, then we would handle it in this way.
Because of the crank that you sent me, I do not lose hope, although it has been a long time. I will return to claim at the post office .... if I have news I will inform you immediately!

I did some testing to day, the engine runs very hot and really vibrates a lot. This goes for both the stock head and my custom turbo one. The low end of the carb is also well too rich and has no low-end adjustment. So a few things that needs to be amended...

Power seemed okay though, on 10% nitro fuel, running without the muffler, and with a  cox 4.5x2 prop, I got close to 20500rpm and an "idle" of 12000rpm...

The pickup from the rich low-end seemed a little more trublesome with the turbo head compared to the stock one. I was running an OS P3 plug but it feels like the stock glow head is even "hotter".

I only have the stock tank mount for mine, and it is too flexible with all the vibrations that the engine gives, so I will have to try find the direct-mount or make something up for it....

Major plus to go with a aluminum back plate for that heater, also aluminum
carb body more cooling the better. I think the engine truly need 24% castor
mix to help fight off the heat. A good engine for cooler weather.

Here it is! and I have it! ... thanks to Mr. Pablo's Management, I already have it .... my brand new G-MarK .03! ....
Now I ask ... who has a big heart to sell me a spare glow plug? ... so I give it a go and breathe easy!



do not pile up, do not line up, there's no hurry ... I just want a spare glow plug plug! LOL

Hello again !, I raise this post to maintain hope if someone has glow plug G-Mark .03 since the only one I own is the engine itself and I do not want to run if I have no backup.
If there is someone who has and wants to sell to communicate with me, thank you!
If there are more interested in this glow plug, maybe we can see if MECOA can manufacture some pieces to cover that need.

Sorry I cannot help with the glowplug, but I just have a couple of things to say and ask. First, that is a very nice looking little engine. And secondly, what is the thumbtack looking piece in the foam just in front of the engine in the case? Thank you.

How many people need these? Would a turbo head do?

Greg I would go for at least 3 turbo heads myself.

NEW222 wrote:Sorry I cannot help with the glowplug, but I just have a couple of things to say and ask. First, that is a very nice looking little engine. And secondly, what is the thumbtack looking piece in the foam just in front of the engine in the case? Thank you.

Thank you for your appreciation, surely with time someone can solve the problem of the glow plug! I have faith!.
The piece you see is the carburetor needle, which comes separately.
It is really beautiful this engine, its small carburetor is a work of art.

gkamysz wrote:How many people need these? Would a turbo head do?

Friend, thank you for taking an interest in the subject, because I could not say what type of glow plug should be made here, if it was the same as the original I understand that the perfect motor, but if there is the possibility of making a device that supports a spark plug and works , I would be interested, if it really works, I could also ask for 3 units or more depending on the value of each one.
I am in the hands of who can solve it, for my part I think there must be several interested, only it is very possible that they have resigned the issue, I want to support it because I really want to enjoy the engine and share their adventures.
Last night I chatted with Jason, a great motors enthusiast and member of the forum, he may also be interested in some units since he has one of these engines but he does not have a backup glow plug ....

1/2A Nut wrote:Greg I would go for at least 3 turbo heads myself.

Hey Brad, you could be our official Tester!

MauricioB THat is a Fine looking little jewel there you have , What CC are these Gmarks ? Looks small like .020 TD ? I hope you can get some more Glow heads so you can enjoy running and fling !! Thanks to Greg i have the .010 and .020 Alum. back plates he made and they Look GREAT !!

A turbo head will work. I haven't really optimised mine yet but the engine will spin the cox 4.5x2 prop at around 20500rpm (on 10% nitro and without the muffler). That should be strong enough I think, but there is also room for more tuning of the head shape.

I could make another head or too but I'm in no position to start producing these for an after-market. If Gkamysz can do it that sounds great, I can possibly help with the dimensions of mine. The thread for the head is an M11x0.5, and it is best to adjust it a little larger to get a nicer fit in the cylinder. There is very little space for both a clamp and an insert, so a commercial product might be better of with a solid head instead (to avoid having warranty issues from ham-fisted users)

Another thing to produce would be a metal backplate, the stock plastic tank is simply too soft and the engine vibrates a lot, that will wear out the carb mount in the long run.

The engine really has a lot of SPI, I don't know why they made it so much, it doesn't make sense together with a carb. I have shimed the cylinder a little but would like to try more. The reduced compression ratio is then easily gained back with a lower head volume. So in the even of a short-run production one should deside what to aim for. Or simply produce two different heads, one for maximum SPI and one for a greatly reduced SPI setting.

The carb also needs and adjustable low-end, the stock carb has no compensation at all, from what I can tell. This means that the Turbo head will run a little colder at "idle" I feel, even with a hot plug like the OS P3.

Here are two different Turbo inserts that I have made, the one to the right is closer to the stock head shape and works well with one or two head shims. The left hand one needed about four head shims, if the cylinder is not shimmed at all:

These engines run very hot and could do with aluminum backplates to aid in cooling
that and the plastic carb body tends to leak the fit leaves you with a loose carb.
Again there the aluminum would aid in more cooling making these engines a leap
over the TD .020 in power in conjunction with a turbo plug that maintains or slightly
improves the existing compression of the original plug. Here castor should be high
I would not run this one under 16% it truly gets too hot my tests at the time was
done with 18% I would go with 22% in the summer.

getback wrote:MauricioB THat is a Fine looking little jewel there you have , What CC are these Gmarks ? Looks small like .020 TD ? I hope you can get some more Glow heads so you can enjoy running and fling !! Thanks to Greg i have the .010 and .020 Alum. back plates he made and they Look GREAT !!

Thanks my dear friend Eric! ... the G-Mark that I show here is a .03, so you have a better appreciation place the G-Mark .03 next to a Tee Dee .020 and a Pee Wee r / c .020 , in order that you can appreciate the size in the best way.
I love small engines and especially if I can control their speed !! ...
By the way, if Mr. Matt developed a carburetor for Tee Dee .020 I would be a firm candidate !!!

gkamysz wrote:How many people need these? Would a turbo head do?

Mr. if in addition to manufacturing the device for the glow plug, you manufacture a back plate for this engine, I would also be interested, I had already thought about making a plate here, but I can wait for if you decide to do the whole, I would buy it to you....

The part has been designed for years. I even have a prototype that didn't quite turn out. It would run in an engine, but I never got around to testing it. A Gmark backplate would be easy enough.

Making two versions of such a low volume part is problematic. I know there are millions of Cox .049 out there. I doubt I would ever sell 100 Gmark heads.

Some of my digital engine collection.

That's a fancy software you have there. Below are my notes as a comparison...

What design did you make for the G.mark .030 engine?

I initially though about making three cooling fins but then settled on two. The engine still runs a bit on the hot side though, not sure why, perhaps there are some issues in the timing with it too.

gkamysz wrote:The part has been designed for years. I even have a prototype that didn't quite turn out. It would run in an engine, but I never got around to testing it. A Gmark backplate would be easy enough.

Making two versions of such a low volume part is problematic. I know there are millions of Cox .049 out there. I doubt I would ever sell 100 Gmark heads.

Some of my digital engine collection.

I can not see the link you left, is it my problem or does the same thing happen to the rest?

On the side of the device for the G-Mark, for your comment You say that you do not think you would make them, since you would sell very few?

Mauricio, if you can't see the image, it's your browser. It refers to an image in my google photos. https://photos.app.goo.gl/kIl9mNuOmqhSVydU2
I probably wouldn't make two types of heads for Gmark .03, only one. I could make one and sell it, but to make it worth my time it would cost a fortune.

Kris, It has three fins now and I was going to start with volume equal to stock. I should get to make a few for testing next week along with TD.020 heads.

Thanks for teh new picture Mauricio. I now see my 'thumbtack' was the needle. My bad, and now I feel stupid. I should have known....

Surfer_kris wrote:That's a fancy software you have there. Below are my notes as a comparison...

What design did you make for the G.mark .030 engine?

I initially though about making three cooling fins but then settled on two. The engine still runs a bit on the hot side though, not sure why, perhaps there are some issues in the timing with it too.

Thank you, it is a valuable contribution, I regret not having the right tools to try it, I do not say that I would succeed, I say I would try ...
Thanks again for your contribution!