Modified cox 049 glow head
 

Hey guys i was cruising ebay a while ago and saw a cox 049 head modified to accept long glow plugs. Well being the resourceful person that I am, Not to mention the burned out glow plugs I had stashed for the " I'll find a use for them someday" box. I mad a jig to drill the hole straight and located the proper taps and viola. Please enjoy the fruits of my labor.

Modified cox 049 glow head
 

Here is the bottom view

head
 

you will probably have to countersink the plug a bit to get the compression ratio right, but they work pretty good otherwise. the best one I had was for a queen bee 074 that I ran on my td 09. it ran right up there with the stock head.

Modified cox 049 glow head
 

I would agree with Wild Fred, make the counter bore deeper to get the plug flush with the inside of the head.

I have tried this several times over the years and found the performance to be below that of a stock Cox glow head, less RPM. I don't know why. Although they are cheaper to replace.

Modified cox 049 glow head
 

Yep, you'll get a power loss even after you trim the recess to let the plug sit at the right depth. It's mostly related to the little ridge. Fine for sport flying if your models aren't meant for speed though. With them down where they should be you'll loose about 800 to 1000 rpm if I remember right.

Some control line speed guys did a few heads with a flat bottomed blind hole so the regular plug just barely touched the base of the threaded hole as the gasket tightened. The idea being to keep the shape of the high compression trumpet plug. Worked pretty well but the fit was critical and the plugs weren't the same size between brands to that tolerance. Net result? Very mixed performance depending on the plug and gasket fit.

Modified cox 049 glow head
 

I just ordered a head and Nelson plugs ($10 for the head, $3 each for plugs) from Doug Galbreath. I'll let you know how they work.
Bob Peterson

Galbreath Glow heads
 

I use the Galbreath Heads & am very satisfied. The compression ratio is better than the original Cox head. The Nelson plug replacement is only $3.00 compaired to the $10.00 to replace the Cox head. The Nelson plugs are designed to accept a lot of nitro without failure. I run 65% nitro in my Cox engines, & they really turn on with the rpm.

Gene Wicks

Nelson plugs
 

Am looking for a better alternative for my COX 049. How would I order one of these Galbreath or Nelson heads and plugs ??

John

Cox 049 head rpl
 

John

Doug Galbreath's web site is:
[email protected]
click on his Free Flight Stiff.


This head will only accept the nelson plug which he sells. Nelson plugs have a special thread size, therefore reg plugs will not fit. The plugs are very durable & do not blow as easy as the Cox plugs.

These plugs will accept 65% nitro. I am not going to state rpm ratings, since engine set ups can differ. You will however notice a large increase with the Nelson plug.

Gene

Modified cox 049 glow head
 

Thanks for the info, Gene. I'd definitely like to check this out.

Tried the address you gave me and it seems to be Doug's E-mail address. Is there a URL for the web site ?

John

Modified Cox heads
 

John

Galbreath's url is:

www.the.printer.net/

The Nelson plugs are made & used in the Nelson Racing engines that turn very high rpm's. That's the quality of these plugs.

modified cox heads
 

John

Sorry I had an error in the url. Try this

www.the-printer.net