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Engine basics => Engine set up tips => Topic started by: frank mccune on February 17, 2020, 09:32:32 AM

Title: Will naphtha or gasoline react with a glow plug.
Post by: frank mccune on February 17, 2020, 09:32:32 AM: Hello All:

These are based on flying in cold weather.

Comments/Suggestions

Frank McCune
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Tim Wescott on February 17, 2020, 01:44:12 PM: I don't know what you mean by "react". A shot of lighter fluid (basically naptha) in the venturi is a great cold-weather starting aid, but I'm not sure if the chemistry of that has much to do with glow plugs.
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Peter in Fairfax, VA on February 18, 2020, 09:19:37 PM: The Wikipedia article describes a catalytic reaction between the methanol and the platinum, but does not answer the question at hand. Link: https://en.wikipedia.org/wiki/Glow_plug_(model_engine) (https://en.wikipedia.org/wiki/Glow_plug_(model_engine))
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: frank mccune on February 19, 2020, 08:09:44 AM: Hi Pete, Tim and Walter:

Thanks for the replies.

The reason that I posed this question was that I see lighter fluid being used as an aid for engine starting in cold weather. I am not convinced that it is beneficial. I have seen it appear to help, and not help. Perhaps the naphtha is masking other problems.

I seem not to have problems starting an engine in 40 degree f weather but my flying mate relies on a shot of naphtha in the Venturi to SOMETIMES start his engine. I know that the test samples are too small to form any opinions, but these mysteries keep me awake at night. Lol. This is what spawned the question re. the interaction between lighter fluid and a glow plug. Will a glow engine run on naphtha? As a child, I heard that it was done. After the run, the engine had no compression!

Frank McCune
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Peter in Fairfax, VA on February 19, 2020, 12:48:09 PM: I'm interested in running, briefly, either denatured alcohol or naptha to flush castor/nitro. Glad that was brought up.
Any comments on good technique and if there should be any oil used?

At present, after flying, I add about five drops of air tool oil to the intake and flip a few times, but no run. And no attention to the tank, at all.
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Dave Adamisin on February 19, 2020, 06:12:50 PM: Hi. When I was working with Pete Bergstrum onthe Evo 60 we came up with the idea to try E85 with a glow plug. It works. The stunt head was a little under compressed. I put the rc head (higher cr) on and it ran great. I was mixing E85 with 15% of Horizons gasoline oil. You will probably need to up the compression ratio.
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Jim Kraft on February 19, 2020, 08:17:02 PM: Glow engines will start easier on gas or stove fuel as it vaporizes much better than alcohol. It is also a great way to add fuel mileage if your tank is not large enough. Adding 10 percent stove fuel will start and run much easier in cold weather, and increase your run time quite a bit. They will run on straight gas if you keep the battery connected, but quit as soon as you remove the battery in most cases. The glow plug needs alcohol to produce the catalyst to make the glow element stay hot.

A few years ago I was going the other way by adding alcohol fuel to my ignition engines to shorten the run time which made the needle easier to set without having an over run or under run. It only takes about 3 ounces or less of stove fuel in 60 size sparkers for the old time pattern and around 5 ounces of alcohol fuel.
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Peter in Fairfax, VA on February 20, 2020, 07:47:28 AM: Good info, but I want to clarify two points.

Regarding stove fuel, there are two types, "white gas" for Coleman stoves, and "denatured alcohol" for alcohol stoves. In general, the white gas is the tank extender.

The catalyst is the coating on the plug, which reacts with the methanol.
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Tim Wescott on February 20, 2020, 01:57:14 PM: I don't know what it does, but I know that a few drops of lighter fluid helps in cold weather.

I also know that a bit of white gas (naphtha) in the tank increases fuel milage -- I've been using it in a couple of planes with oh-so-slightly undersized tanks, in lieu of making bigger tanks.
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: Steve Helmick on February 23, 2020, 07:42:58 PM: Quote from: Tim Wescott on February 20, 2020, 01:57:14 PM
I don't know what it does, but I know that a few drops of lighter fluid helps in cold weather.

I also know that a bit of white gas (naphtha) in the tank increases fuel milage -- I've been using it in a couple of planes with oh-so-slightly undersized tanks, in lieu of making bigger tanks.

Tim, are you sure that white gas is the same thing as Naptha? I thought you (and Dave Royer) added some Coleman fuel to extend the run time. "White gas" is kinda old fashioned. We used to buy it for the Coleman stove at the gas station...when gas stations had lube racks and mechanics on staff. What the heck is "naphtha"? Is that Naptha with an extra hydrogen atom? LL~ Steve
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: John Leidle on February 24, 2020, 10:07:36 AM: Naptha is quite toxic....
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: John Leidle on February 24, 2020, 11:39:50 PM: True enough.
Title: Re: Will naphtha or gasoline react with a glow plug.
Post by: FLOYD CARTER on February 25, 2020, 10:20:29 AM: When it's cold enough to require lighter fluid to start an engine, I stay at home, by the fireplace. Flying is a fair-weather activity.