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Engine basics => Engine set up tips => Topic started by: Art Neto on June 07, 2019, 08:21:39 AM
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Hi guys
I just got a very nice O&R .23 with what seems to be the original glow plug. My question is... what voltage does it require to fully light up? My modern ni-start barely works on it. Thanks for any info..
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While SOME (very few) glow plugs will take 2.0 VDC -----most of them should not feel any voltage above 1.5 VDC......seriously.....especially vintage glow plugs
THERE are glow drivers that can provide a safe 1.5 VDC and a variable current (RCATS)
Some are simple (power panels) and YOU set the current
in almost all cases two or more 1.5 VDC large format primary cells---(like a D cells) soldered in parallel....same volts, max current....is very solid ignitor for a full season of flying......
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Back in the old days, every one used one or two 1-1/2 volt door bell batteries, dry cells, either in parallel or alone. They were a full 1-1/2 volt where our nicads or NIMH are only 1.2 volts. The old Olsson and Champion glow plugs do not work well with less voltage. It should work fine on 1-1/2 volts if you have plenty of current available. I have several of the Ohlsson 3/8 glow plugs, and some Champion glow plugs of both sizes.
They are a little unhandy because a normal glow driver will not fit any of them. There again, in the old days we used alligator clips for the plug connection. A lot of this spilled over from the ignition days where two batteries were used in series for 3 volts for a booster to start. it was a natural thing to use alligator clips on glow.
Just a little history as I remember it from before dirt was invented.
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Jim
Would you sell a couple of the Ohlsson plugs? I live in Brazil and it's virtually impossible to find them here..plus I only have the one that came with my engine..
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I need to round up all the old plugs that are sitting in junk boxes and mount them on something. I have at least one or two that look like this one. I thought that maybe they were an Arden plug. Never tried to make one glow. I just find them interesting and cool to look at. Just a small but vital part of our hobby's history.
Type at you later,
Dan McEntee
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Are the OK plugs same vintage as the ORs?
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Hey Art. All of the ones I have are the 3/8 24 thread. Sorry, I do not have any of the 1/4" Ohlsson plugs. I do have some Champions though I believe.
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Bill, the OK plugs are about the same vintage. I started flying OK Cubs in about 1950. The glow plug came out in about 47 so the OK plugs would be about the same vintage.
I have an old AirTrails Annual, from 55 that has the results of the Nats in it. it is interesting to note that many control line planes fitted with Fox 35's used OK plugs. They gave a lot of info on the planes that were flown. Like how many coats of what brand of dope. What prop, starting battery, wt. of the plane, what brand of wheels, and a host of other stuff. Very interesting reading.
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Mine is the 3/8"... 😊
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Hey Art,
That may be a cold plug. My cold plugs don't light as bright as hot plugs with the same power settings. I have to turn the juice up on cold plugs to get them lit as bright as hot plugs.
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Hey Art. That is a 3/8 plug after I looked a little closer. I had never seen any Ohlsson's from the 33 and smaller with a 3/8 plug. But you have one. I only have two which I would like to keep for my collection.
Larry Davidson makes a 3/8 to 1/4 adapter bushing to convert them to 1/4. That would be your best bet for running on glow. Then you could use a standard glow driver.
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Although the cylinder head looks like aluminum, the glo plug actually screws into the steel cylinder. Hard to strip these threads, but someone has re-drilled and tapped for the large 3/8" glo plug. All O&R engines, except for the 60, came with 1/4" spark plugs or glo plugs.
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Thanks everyone!😊