chris6414

My Feedback: (10)

Anyone ever tapped an old spark plug for a glow adapter? I could buy one for $14 but just wanted to experiment on my 33cc Poulan

Also, what if you don't increase the area of the walbro jets for glow fuel? Will it not run?, be low power? I don't know if I like the idea of messing with the carb. Any easy ways to do this?




El Cheapo

Antique

My Feedback: (4)

You can tap a 14 mm plug for a CM6, but not a 1/4 32 glow plug...
Most standard carbs won't pass enough fuel for glow..Check with Dick at B&B, I think he has some info on making glow carbs .....
www.bennettbuilt.com

Captain Ramius

If the hole left from removing the porcelin is small enough you can tap the hole directly. If not then the hole needs to be filled and then drilled and tapped for the glow plug.
The carb if not modifed will be lean.

chris6414

My Feedback: (10)

Thanks for the info. I guess I'll have check out modifying my carb

chris6414

My Feedback: (10)

Tried to tap the plug last night. Holy moly is that porcelan tough! I destroyed the plug getting it out. Either way, my plug's hole was tad too big. I'll have to pick up an adapter.

av8tor1977

My Feedback: (6)

You can gut a spark plug if you're careful. I've done a number of them to make a fitting to inject air into cylinders. You have to clamp it in a vise and work slowly, and with protective glasses. Just keep chipping away at the porcelin until you get it and the center electrode out. If you drive out the center electrode first, then it's easier to collapse and knock out the porcelin. My thought for making a glow plug adapter would be to then make a small piece of metal and weld or braze it into the end of the spark plug. Then drill and tap that for a glow plug. You may have to drill the upper metal part of the spark plug for your glow plug wrench depending on how thick it is.

Just my ideas,
AV8TOR

Antique

My Feedback: (4)

If you have a lathe you just turn down the top part of the metal and the porcelain falls out in one piece

Turbobeaver

Out of curiosity,where abouts should the glow plug be located inside the spark plug adapter?Should it be level with the bottom,slightly out the bottom,up inside?Has anyone got a picture of one of these things for us to study up close and use as a reference?

Rupurt

If you have a lathe you can make the whole adapter out of ally in about 20 minutes.(granted it has to be a thread cutting lathe)

chris6414

My Feedback: (10)

I don't think the specs would be that strigent as the glow plug just needs to ignite the fuel and it is hot all the time when starting and running. Probably as close to the inner tip as you could get would be best in order to stay hot.

Antique

My Feedback: (4)

Best to make it as close to flush as possible...I put a CM6 NGK spark plug, short reach, in a G26 to make it shorter from the crank to the top of the spark plug...Lost 2 or 300 rpm because of the loss of compression due to the extra space in the combustion chamber...

av8tor1977

My Feedback: (6)

Yes, you don't want to lose any compression. Just be sure however, that no threads of the glow plug stick down into the combustion chamber as this can cause other problems.

Good luck,
Av8tor

captinjohn

I do not think you even need a thread cutting lathe. Just turn the stock to the right dia and use a thread die to make the external threads. Tap for internat threads. You may not even need a lathe...if you can find stock the right dia. Added..... another Idea.....find a bolt with the same threads as the spark plug you took out and cut it to right length and drill & tap it to make a adapter. Capt,n

tripp3d

I read this thread yesterday and after exhausting myself for about 20 minutes trying to drill the electrode out of an old spark plug, my mind started wondering if there was anything else that would work better...A 14 mm piston stop for adjusting valves on a 4 stroke. Its all aluminum and a much easier conversion. I also drilled the seat for the needle valve and the high speed adj screw in the carb to flow more fuel. The engine is still in a Stihl weedeater as of now but even with a clutch, driveshaft, gearbox, and cutting head it had good power on 15% nitro. Now if I could only find a purpose for doing this...

chris6414

My Feedback: (10)

Will drilling the adjustment seat allow the added fuel flow for glow operation. I keep hearing about twice the area not twice the diameter and I really don't want to go popping the plugs out to drill them.

tripp3d

Yes you can run glow fuel through a walboro or zama carb if you drill out the port where the needle valve rests. These needles have a viton (rubber) tip and dont require a rubber seat. This allows you to actually ream out the hole just a litte. one or two drill bit sizes. The needle will fall into the hole a little farther after you ream it so be sure to bend the tang down that holds the needle to counter the modification. Also you may want to ream the high speed mix screw as well to flow more fuel. And one last note, correct me if I'm wrong but it seems to me since nitro carries its own oxygen and we are trying to cut down on the amount of air in the air/fuel mix a lower nitro content might help. I ran mine on 15% which may be a bit on the high side? Anyone?

Turbobeaver

Don't know if your aware already or not but Peter at Wacker Engines does sell a glow plug adapter($15) as well as the glow prop hub($20) designed to fit straight onto the end of the crankshaft:

http://prophub.tripod.com/

The Zenoah glow plug adapter designed to fit the G23 or G26 is also available from Horizon for $9.95(ZEN23445).I guess it all depends on what size engine and plug your trying to convert.

chris6414

My Feedback: (10)

I saw the one on Wacker engines and will probably get that one. About the nitro, I read a thread about a ryobi on glow that ran with as little as 3% Nitro with no carb mods.

Turbobeaver

Wonder why you just couldn't make an intake manifold adapter to take a large Supre Tiger glow carb(ST2500 etc?) and just use muffler pressure to pressurize the gas tank like any other glow airplane 2 stroke?

captinjohn

Turbo B: I am sure you can. A perry pump or any pump will get the fuel to carb and may make for more steady running over muffler pressure. You can also make a pump from a old walbro carb. There is pics how...look in search mode. Capt,n

chris6414

My Feedback: (10)

About the St carb idea. It would work but I'm going to experiment with the stock WT-324 to see what kind of performance I get. I'm a cheap SOB and would have to purchase the carb and fabricate the manifold. As soon as I can get everything together annd fired up I'll post my results.

Turbobeaver

RCIGN1,when you are referring to the top part of the metal,what area is that exactly and could a dremel tool with a cutting disc be used to do the same job and still have the center porcelain come out in one piece.A picture here would sure be worth a thousand words right about now.

oslim

Does anyone have any actual experience using any petroleum-based fuel with platinum-wire glow plugs? I remember some earlier threads ( Spark-to-Glo Conversions ) that referred to using unleaded gasoline, white gas, naphtha, Coleman stove fuel, or Walmart Yukon Trail camp fuel alone or mixed with alcohol. I understand that the platinum-wire glo plugs are primarily intended to ignite alcohol. Will they ignite any petroleum products at all? The reason for my interest is not so much to save fuel cost, but to use the gasoline fuel jetting and avoid damage to carburetor gaskets caused by alcohol. Thank you.

chris6414

My Feedback: (10)

I would love to hear any advice regarding that question as I am concerned about if I go to glow, that I will most likely have to rebuild the carb annually due to alcohol deteriorating the gaskets and pump parts.

Antique

My Feedback: (4)

5 minutes once a year to replace $5 worth of parts...What a chore....
The part of the spark plug just above the hex is what you cut off to take the porcelain out..A Dremel will do it just fine, just takes longer......The porcelain is cemented in but comes out easily when the metal is cut off..I usually take about half the hex off, leaving just enough for a wrench to tighten it in the head....
A glow plug won't ignite gasoline.....