Glow Plug Idle Bar
 

I'm new to Glow and not overly knowledgeable about glow plugs. What purpose does the idle bar serve on some plugs? What are the advantages/disadvantages of having one?
Thank you for your response.
Ward

RE: Glow Plug Idle Bar
 

Never mind, did a search after asking the question and found lots of answers. Smart huh?

Copied from another post somewhere. Please let me know if this is incorrect information.
Thanks.
Ward

No but. Idle bar plugs came out when engines had a baffle across the piston which directed air from the intake port up into the cylinder. Fuel would stick to the baffle and fling off as small droplets. The idle bar stops the droplets from hitting the element. They do nothing for inverted engines. Since they are largely used on these older engines the heat of the plug is made to suit them, mostly slightly colder than say an OS #8. Unless you are running slightly higher nitro than most then a modern plug would most likely work better.

RE: Glow Plug Idle Bar
 

That sounds about right. I've only heard that the idle bar was there to help keep the fuel from cooling the element when you throttle down. I have never heard about the history of it though.

I've been flying for about 15 years and here's what works for me. In all of my two-strokes I use the OS #8. In my four-strokes I use the OS type F. I also keep a couple K&B long idle bar plugs because I sometimes encounter an engine that seems to run better with that. Often students will come out to the field with some unknown plug in their engine. Sometimes it will work fine, sometimes not. I remember fighting with one guy's engine for an hour trying to get it running right. Finally we put a K&B idle bar plug in and it ran fine.

99% of the time engine problems are due to one (or more) of three things:
1. Engine is out of adjustment (high and/or low end needle).
2. Bad fuel.
3. Bad glowplug.

That's my 2 cents worth...

RE: Glow Plug Idle Bar
 

Thanks for your response,
Yesterday I ordered several O.S. #8's and several #A3's. Figured that a couple different types may be handy.
The Glow Plug that was sent with my .61 Thunder Tiger was some kind of generic I guess as I could not find a maker name on it. It only lasted about 20 minutes of actual run time while I was breaking in the new motor. Went out to actually fly the plane the other day and the darn thing would not light up. Glow Starter was working properly but the plug would not heat up. Of course as I said I'm new to glow and did not have any spares yet and living where I do the closest Hobby shop is 150 miles away and the club is sort of hit and miss as far as anyone else being there. (Mixed blessings!) So now I sit and wait on the U.S. Mail! I was hoping that this type of performance would not be the norm for glow plugs I'm not broke but at $3.00 to $5.00 dollars or more a pop that could send me back to electrics eventually. Ha! Ha!
Thanks again,
Ward

RE: Glow Plug Idle Bar
 

Don't know why there is an idle bar on plugs, but about 4-5 years ago I got tired of trying to keep up with what plug worked best in what motor. OS#*, Enya #*, 2 stroke, 4 stroke, large, motor, small motor!!!!!!! It was crazy, then a fellow flyer suggested trying Fox Miracle plugs. Now I use them in every motor regardless of size, 2 or 4 stroke. I very seldom have starting or tuning problems, and very seldom need to change plugs. I got a good deal on card of them at a swap meet a few years ago, and still have some left. I have about 15 glow motors & they work good in every one, without exception. I still have a lot of other plugs that are takeouts and acquired through trades etc, that I use when breaking in motors.
I'll stick with what works for me.

RE: Glow Plug Idle Bar
 

I use the fox miracles too i am not going to pay a 9$ a plug just for the O.S. name. My uncle had a st 90 and put a number 8 O.s brand new in it and the motor wouldn't half run and we went and got a old 7 year old fox plug out of a old 40 motor and put it in and it ran like a top.. $9 O.S. or $2.56 for a Fox :eek: no brainer

RE: Glow Plug Idle Bar
 

I have never paid $9 for any OS plug, not even the 'F'. You must be shopping at the wrong place. Buy them in quantity from Tower. But like I said, some engines like different plugs.

RE: Glow Plug Idle Bar
 

aww! Geeze! and to think i just dropped $45:00 bucks on a set of 3 plugs for the .91 Saito. I just wanted some back up as I live 150 miles from the nearest LHS too! and the Stock plug that came with the Saito still runs fine after burning 6 gallons of 10% Nitro in it. However the cheaper plugs that are available are still at the $5:95 price. :(

Sometimes it is tuff to be northern canuck!

Rick.

RE: Glow Plug Idle Bar
 

The history that I have heard is that the idle bar is a holdover from the days when glow engines were open exhaust, without mufflers. The idle bar was necessary to get a decent idle, lacking the backpressure a muffler provides.

Like many a beginner(some 21 flying seasons ago) I used some idle bar plugs in my first engine, a K&B .40. That is until the scolding I got from experienced members for using such a plug! I was told then, and I have found, through countless flights and no telling how many engines over that twenty one year period, that idle bar plugs are completely unnecessary in modern engines. I have seen instances, in fact, where the idle bar came off the plug and trashed the piston and sleeve.

I was a serious pylon racer for a number of years (at least I thought I was) and as such, through experimentation, I identified one plug that works the best all around. The plug that delivered the best performance and longevity, even under the brutal conditions of pylon racing is the McCoy MC9 (also marketed as the Hangar 9 MC9). I have flown entire seasons on the same plug, sometimes longer than that! As for idle reliability, well, let me just say that some of the races were won or lost based on whether you were able to earn the bonus point for landing and coming to a complete stop with the engine still running.

As far as for 4-strokes, my plug of choice will always be the OS F. I have flown two seasons with both a YS .63 and an OS 1.20 Surpass III and I am still running the original OS F plugs. By the way, that is with 30% all synthetic oil fuel.