Wild Foamy

hi guys

would it be possible to use an old glow plug head from a cox 049 or similar, drill a 1/4' hole in it and tap it with a 32tpi ME tap and then screw a standard hot glow plug in there (like the enya #3) and use that instead of replacing the whole head every time a plug dies?

Mr67Stang

Take this questin to the 1/2a 1/8a forum. They are the experts on tiny engines. The smallest I use right now is a .061 so I can't answer for you.

Campgems

There are heads on the market that do just that. I would go with one of them as there may not be enough meat in the Cox head to do the job.

Don

burtcs

Wild Foamy:

Feel free to use the search function for this. Find out from the posts why it is marginal.

regards - Steve B.

tewitt1949

If you go to ebay and search o49 or tee dee you will see then for sale now.

digital_trucker

Wild Foamy - the best bet is to get a Hypercolor turbo head and use turbo plugs.

http://www.hypercolor.biz/index.html

Wild Foamy

the Hypercolor heads do look pretty nice, but i was looking for maybe a little homebrew project or something.

i can use a lathe, mill and have made underheads for my Truck engines before, so im no stranger to this.

if a completely new head is needed then that shouldnt be a problem, would it be too hard to spin one up form alluminum in the lathe? (using the old one as atemplate and maybe adding 1 or 2 mm on top of it to give it more "meat")

Campgems

I would think 5 or 6 mm would be more like what you will need to add. Could be wrong though. Most of the short glow plugs are at least that deep in the threads, and you will still need a little meat above that. I don't have an old cox head right now, but if you have one, you could use a ball bearing inside the combustion chamber and measure from it to the outter part of the head to get and idea of the thickness. For all it trouble though, you can still get the heads. Cox was selling full engines for less than $10 recently. If I were into 1/2A stuff, I would have loaded up. I even though about it for pistons and cylinders for making a multi cylinder engine.

Don

digital_trucker

Using a normal short plug as opposed to a turbo plug will rob you of RPMs.

gcb

Actually, to answer your question...NO. If you drill a 1/4" hole, you can just place the plug in the hole. Remember, 1/4" is the OUTSIDE diameter of the plug threads. You would need a smaller drill.

As others have mentioned, you lose performance with a conventional plug...mostly due to the extra combustion area around the plug since it seals at the top by the plug gasket. Most seem to find the Galbreath head and Nelson plugs work best (they seal at the bottom), but some are trying the Turbo plug setups.

If you do not need the performance and just want to play around, the 1/4" x 32 taps are available from Harry Higley via your LHS or an online store. Perhaps the drill too.

George

digital_trucker

The nice thing about turbo plugs is that a standard plug lighter fits 'em. Nelson plugs are too big for a normal glo-clip. Unfortunately, my Hypercolor head needed to be lathed to allow clearance for the glo-clip.

indoorff

My Feedback: (2)

I bought one of the RJL standard plug conversion heads for one of my 049's just to try. I ran the engine first with the cox glow head, then a second time with the standard plug head and there was no RPM change what-so-ever. It certainly does not seem to decrease performance in any way I can measure.

Chris

digital_trucker

indoorff - as with everything connected to these lil' beasties...your mileage may vary!

ptulmer

My Feedback: (5)

The regular head that comes on the Surestarts is terrible. I'm not surprised you didn't find any difference! Compared to a high compression TD head/ Norvel head/ Galbreath head/ Hypercolor head, you're down anywhere from two to four thousand RPM with a standard plug head.

Neat performance trick: Chuck the head up in your lathe. Turn the bottom fin off, then shorten the seat until the chamber is sized close to a high compression head. Your cheap low comp head works like a TD head for a SS!

gcb

Neat! Make your own squish band.

George

gcb

Chris,

The standard plug provides easier starting and handling to a beginner or sport flyer as well as less stress on the moving parts. TD's were set up with much higher compression for much higher performance than the reedies. If you use high compression heads and trick parts on a reedie, you are going to blow some engines.

If the standard head (or the RJL) gives you the performance you need, by all means enjoy it. Your engines will last longer.

Most compare the conventional 1/4" x 32 plug to the high performance heads.

George