Remby

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I have tried to do this, have one that was drilled out and tapped. It was done to see if a H.C. ,burned out head could be used to hold a glow plug.

It ran the engine I tried it with, but not very good as the plug is a short, I need to get a long and give it a try.

The work is not as easy as it looks because of Glow head construction, finding a way to hold the work, etc..

Some others try this ? Also, what would the proper drill bit size be, along with the tap thread size needed?

Will this work at all, or a bad use of time?

Let me/us know the thoughts here..
Thanks!

Andrew

Remby --

Use a Galbreath head/NELSON plug combination. Both may be purchased from Larry Driskill at [link=http://www.kittingittogether.com]Kitting It Together[/link].

Tim Wiltse-RCU

Remby,

It's been tried many many times by people over the years. ALL have failed. Power will be way way down.

Later,
Tim

burtcs

Do what Andrew just told you. The Galbreath head and Nelson glow plugs work GREAT! Not only that but the Nelson plugs are a heck of alot cheaper than the ripoff Cox glow heads and will actuallyl add more power (RPM). How many times do you need to ask this question?

HTH - Steve B.

Remby

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burtcs;

Only once as I did !

Thanks for the info, all.

Tim Wiltse-RCU;

Perhaps you could inform as to the failures, why is this so hard to make? I purchased a few of Hobblers .049 adapters from Ebay, and they work as well as the standard Cox head.

Something to do with the H.C. needs?

Also, the tap size and drill for a standard plug would be helpful.

I would think with the level of expertise shown on this forum, somebody here may have had some suscess, I never like to here it can't be done..

Andrew;

Thanks for the link! He has the glow plug for the glow bee head as well, how will this compare to the Galbreth?

Thxs again all!

bsindel

Hi Remby,

After lurking about this forum for the last couple of years, my understanding of this is that
the opening around the glow element in standard glow plugs is so large that it makes the
combustion chamber to large to get the kind of compression that the cox engines need in
order to turn up good rpm's. Also, the seal around the standard glow plug is at the top
of the threads which allows more space to lose compression around the threads of the glow
plug. It may be a small area, but these little engines are apparently sensitive to it.
If you take a look at the base of the Nelson plug you will note that it is chamfered and that
the bottom of the glow plug hole in the Galbreath head is cut to match it. This seals off some of the
space that would be added in using a regular glow plug. It's kinda hard to tell from the pictures,
but if you can look in the end of the Nelson plug you would see that the open area around the glow
element is reduced when compared to a standard glow plug.
As for the thread size of the standard glow plug, I believe it is a 1/4-32. If I've got it wrong
I know someone will chime in and let us know. This topic has been discussed a number of
times on this forum, so a search for this topic will yield more info if you want.


Experiment anyway, what the heck,

Bill S. (the other Bill)

Andrew

Remby --

I cannot comment on GloBee head -- I believe there were some posts some time back that were not too complimentary on its performance.

Bill S. has pretty well covered the bases WRT the plug differences. The NELSON plug was developed by Henry Nelson, of pylon engine fame. Nelson engines have been dominant in Formula I, Q40 and Quickie 500 -- if a .40 doesn't turn 22,000 on the ground, it may not be competitive. Bottom line is that the plugs are designed for high power, high RPM. On our engines, they just loaf.

The NELSON plug is 11/32 x 32. Harry Higley sells the 1/4 x 32 and McMaster-Carr has them also.

Remby

My Feedback: (3)

Thanks for the info guys.

Yes, it would look to be workable, and I hate to waist things. I just tried to give it a go. Again, the Hobblers adapters from Ebay work good, but are more like the standard glow head, and I still have some new cox H.C. heads for now.

The Galbreath looks like the way to go, then. He has Fox plugs on the site, do those work with the Galbreath adapter, or just the Nelson plugs ?

Thanks again for the info everyone !

Bipe Flyer

Has anyone tried the Nelson plug on an .020? I tried a standard, but not enough compression.

Andrew

Only the NELSON plugs will work with the Galbreath head -- the thread is 11/32 x 32 and the Fox is 1/4 x 32. The NELSON also seals at the base and the FOX seals like all standard plugs - at the compression washer.

Remby

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Thank you Andrew, copy that on the washer.

That Galbreath adapter plug is the only down side, then. If the Nelson plugs ever stop production then the adapter becomes a paper weight?

Would like adapters that use the "Fox" standards type for the ability to purchase anywhere. But then, as was stated above that won't work anyway, at least not with the H.C.

Did not Glo Bee make a H.C. type head adapter that used standard glow plugs?

Andrew

That's true, but the entire 1/2A engine market is pretty shaky right now and the options are limited. SIG tells us that the NORVELs are back in production, but they remain as scarce as hen's teeth. Since SIG dropped their dealer network pricing scheme, your only choice is to find a LHS or On-Line seller that stocks SIG products or pay the higher SIG pricing.

The CS engine has not been well received. Brodak is now importing a .049 with a .061 listed "Not for Sale", but these look to be CS engines -- or at least of the same linage. Both will probably be C/L only.

Your options are to lay back a supply of NELSON plugs to keep your stock of engines running if the market collapses completely.

The pylon market is a small, but well financed group of flyers -- you can't be competitive without owning a gold mine somewhere. If NELSON gets out of the game, someone will probably pick up the slack.

Remby

My Feedback: (3)

Andrew;
Thanks for the info. 1/2a, and the engines have always been a "niche" market, at least to some. Think if Cox engines were first marketed by Leroy in the mid 90's, how different it all would be.

I will look into the Galbreath with the nelson plugs, then. How do these compare to the H.C. glowheads from Cox?

Also, I do have a couple of the old Glo Bee sport heads, but the plug is burnt out. Are these long gone, or can they be found anywhere? Even burned out, they look kinda cool on that fresh, vintage motor.

One thing leads to another, I will look into the CS engines, to see the scoop about them.

Thxs !