glow plug life

[Dan Berry]

Setup: Tower 40.
5% nitro, 20% synthetic oil. Plug is a SIG idle bar.

Question: How many flights should I expect from a glow plug?

[Brett Buck]

dupe, disregard

[Brett Buck]

Setup: Tower 40.
5% nitro, 20% synthetic oil. Plug is a SIG idle bar.

Question: How many flights should I expect from a glow plug?

   500-1000, at which point it will start losing power. It should *never* blow. Unless it is SIG or you add Armor-All, and then you may lose power in about 50 flights as the plug develops "taters".


    Brett

[Dan Berry]

It's a Sig plug and I hafta use Armor All for foaming.
I ain't gettin' 500 flights, that's certain.

I'm not used to running engines for six minutes. FF stuff doesn't run that long.

[pat king]

Armor All contains Silicone. At combustion temperatures that deposits Silicon Dioxide (Quartz) on the element. The Silicon Dioxide coating kills the catalytic action of the plug element. The element will glow brightly, but without the catalytic action the plug is worthless.

Pat

[Perry Rose]

Fix the vibration problem and the foaming won't be a problem.

[big ron]

In the last bunch of sig plugs that me and Brent Rogillio bought we had some that were bad out of the pack. I have some that are over a year old in other planes that have a lot of flights on them.

[Brett Buck]

It's a Sig plug and I hafta use Armor All for foaming.
I ain't gettin' 500 flights, that's certain.

I'm not used to running engines for six minutes. FF stuff doesn't run that long.

  Does it blow, or does it just lose power?

    Brett

[Fredvon4]

Some times I try to use logic when thinking about why many "wives tale " fixes are so prevalent

Or, Why if something is so simple, why would NOT the manufacturers use it

I posted on another forum about fixing a foaming problem before resorting to questionable additives like Armor-all

Got blasted fairly soundly by the folks who swear by the additive

I blend my own fuel 80% or the time and only use Sig Champion (Cox engines) or Riche's Brew (Nelson Combat engines) as delivered

I have not yet decided if I ever have or had a foaming issue

That all said...I gotta believe that if foaming was as big a deal as it sounds---- the chemistry EXPERTS who design fuel blends would use something as cheap as Armor All----- IF it made sense and caused NO adverse reactions

The fact that THEY DO NOT ADD this one or two drops per gallon speaks volumes to me

I have only blown plugs from over volt or over compressed high Nitro...they are too darned expensive to screw with 'taters from some questionable additive

Add to this the FACT that Armor-All 20 years ago and today are NOT the same formulation

I think I will stay with my regimen of building solid aircraft,  balancing props, and padding fuel systems to PREVENT vibration induced heavy foaming

jest me thinking logically

Don't know if an (anti foaming) additive is IN the BLEND but I can take a Gallon Jug of Riche's brew right now shake it hard and fast and not see any serious foaming...yes tiny bubbles that dissipate rapidly

The Sig Quarts are all castor blends and have slightly larger bubbles but same fast dissipation...not what I would call foaming

Add to that I had a hard time finding many plugs you guys recommended for my engines and they were a bit pricey so I do not have many of them...I gotta believe clean pure fuel (even if foaming some) will not kill them

The again I am a sport non competition flier... and I tend to giggle and not get POed when I crash a model

[Randy Cuberly]

Fred,
I think your logic is perfect.  Armor All is a poor solution to a non-problem.  If vibration is a problem, fix the vibration!

Most of the so called "foaming" issues I've seen in the past were actually tank problems or severe vibration that will eventually and surely destroy more than the fuel!

Armor All works really good on motorcycle seats and automobile dash boards...not for the inside of engines!

Randy Cuberly

[Brett Buck]

Some times I try to use logic when thinking about why many "wives tale " fixes are so prevalent

Or, Why if something is so simple, why would NOT the manufacturers use it

I posted on another forum about fixing a foaming problem before resorting to questionable additives like Armor-all

Got blasted fairly soundly by the folks who swear by the additive

I blend my own fuel 80% or the time and only use Sig Champion (Cox engines) or Riche's Brew (Nelson Combat engines) as delivered

   The ability of silicone additives to reduce foaming is certainly not an old wives tail, it is easily demonstrated just like Keith Trsotle recently suggested.  Whether or not it causes additional issues (like plug taters) also seems pretty clear to me, but far less obvious. And in fact, SIG does (or at least did) contain something that acted as an anti-foaming agent of unknown type. Some of us have convinced ourselves that this anti-foaming agent caused the issues we had with plug taters using SIG, which disappear completely when we use Powermaster, or home brews that are otherwise identical to SIG that we know do not contain any anti-foaming agent. Note that tatering only became a problem when we went to 61s and larger. The smaller engines (like the 40VF) don't seem to do it. Our guess is that the higher temperatures in the middle of the cylinder are enough higher to polymerize whatever causes the tater, but that's just a guess. There is no doubt that the larger engines run generally hotter.

   There are other anti-foaming agents that people have tried (like Kodak Photo-Flo, which may actually make MORE foam since it's kind of like soap) with unknown effects on plug issues.

   I haven't had any detectable foaming issues for many many years so I don't need anti-foaming agents, so I am set. If you *do* have a foaming problem, it is best corrected some other way. But, in a pinch, foaming is a lot worse than a periodic plug tater, so I wouldn't fault anyone from trying. 

     Brett

[Dan Berry]

It's a profile Oriental.
I don't think it has a severe vibration problem. The wing to fuse joint shows no signs of stress. It doesn't feel too 'vibratey'.

I was having a problem with the engine run about half way through the flight. It just sped up and ran way. Fuel foaming was diagnosed. I did fix a tank mount and added the ArmorAll. The fuel has no anti-foam ingredients that I know of. It is by RedMax and I didn't spec any anti-foam.

I have had a couple plugs-not the SIG- go bad and cause all sorts of needling issues. It took me several flights to realize it was a wonky plug. On my Free Flight stuff I can diagnose a bad plug pretty quick.

The most recent was in the hourglass. It just quit.
This plane will lean out a bit for several laps before running empty, as well as barking a couple of times. It just quit like a switch was thrown. The meter says the plug is good but I'm pretty skeptical that it will run. That plug had maybe 70 flights.

I do wonder if it might be a bit overcompressed.

I am by myself when flying and there is nobody near me with any knowledge about what I'm doing.

[Randy Cuberly]

Look at the plug element under a good magnifying glass.  If the problem is "taters" as Brett says the little hard usually round deposits on the plug wire will be fairly obvious.

If you can get one try a Enya number 3 or a thunderbolt R/C plug!  I believe they are hotter and more consistent than the Sig plugs.

If you're running a uniflo tank system a tiny hole somewhere in the tank (probably about halfway over from the fuselage) could cause what you're experiencing.  Even a small hole in the fuel tubing etc could cause this condition.

Being over compressed could be an issue.  It can cause excess heat that could result in what you're seeing but I would believe a small hole in the fuel system is more likely.

Randy Cuberly

[Lauri Malila]

Brett,

What colour are those taters that you have experienced?
I use 20/80% fuel with Motul Micro oil. It says "synthetic" in oil bottle but I have some doubts.
My engine (.77)is quite efficient, I use about 80ml/2,8oz fuel per flight.
There is no real carbon buildup problem in the engine, but after 20..30 flights the plug (Enya#3) shows signs of carbon; slight lack of power at richer setting and a small drop of rpm when glow is removed.
At that point the filament is perfectly clean except for first 0,5..1mm in very root near the point where it is spot welded to plug body. There is some reddish brown residue. When I scrape it off, the engine works normally again.
Also the team race people who have used Motul Micro have complained about "red carbon", which makes me ponder if it is not caused the oil itself but the red colour in the oil. L

[Dan Berry]

I'll look at the plug under a lens.
The ArmorAll did solve the runaway engine issue. The tank and plumbing seem to be leak tight.
I'm busy prepping some stuff for FF at the Nats.......something I know how to do.
Two stunt flights is more run time than 40 or 50 FF flights so it's a different world.

[Randy Cuberly]

I'll look at the plug under a lens.
The ArmorAll did solve the runaway engine issue. The tank and plumbing seem to be leak tight.
I'm busy prepping some stuff for FF at the Nats.......something I know how to do.
Two stunt flights is more run time than 40 or 50 FF flights so it's a different world.

When you say that the tank and plumbing seem to be leak tight...have you actually checked it under pressure under water?  It's usually nearly impossible to find a small leak any other way.

Remove the tank and attendant fuel lines plug them all except one, using a syringe pressurize the open one with air while holding the tank and lines under water.  If there are no air bubbles then you can say there are no leaks...visual inspection counts for nothing when it comes to leaks.

Randy Cuberly

[Brett Buck]

Brett,

What colour are those taters that you have experienced?

   Very dark red, very dark brown, or black. When you scrape off the surface, it is a medium tan underneath.

     Brett

[RandySmith]

   Very dark red, very dark brown, or black. When you scrape off the surface, it is a medium tan underneath.

     Brett

What Brett  said  and   ..In addition  I have grown white  and  red  taters  on occasion??  brownish red is most common

More castor grows  more  taters

Randy

[Dan Berry]

When you say that the tank and plumbing seem to be leak tight...have you actually checked it under pressure under water?  It's usually nearly impossible to find a small leak any other way.

Remove the tank and attendant fuel lines plug them all except one, using a syringe pressurize the open one with air while holding the tank and lines under water.  If there are no air bubbles then you can say there are no leaks...visual inspection counts for nothing when it comes to leaks.

Randy Cuberly

Did it. With the ArmorAll it runs steady. I have used a few plugs. I didn't know that the silicone would knosh the plugs but I will look at them.
It is a uniflow tank.

[Brett Buck]

What Brett  said  and   ..In addition  I have grown white  and  red  taters  on occasion??  brownish red is most common

  I think the white ones are the same as the others, except that the black outer crust hasn't formed or got knocked off. I was just looking at old glow plugs for taters, but I don't have any that show the classic look. I have one proto-tater that does indeed look bright white with a rough appearance. Fully formed, the look like smooth plastic drops melted on to the element, then maybe charred on the outer surface.

    Brett

[Lauri Malila]

I went through quite a pile of used plugs today and found 2 differend things:
-brown/black buildup near the root of filament, where the spot welding is. It must be just some organic stuff from oil, like castor residue. (At least infrared spectrometer found signs of castor in my "synthetic" Motul oil but propably we need gas cromatography to verify it) It forms because the plug body sucks heat from filament thus it is not hot enough to burn away. Deeper in the coil all organic will burn away. After I scrape it away with my small carbide scraper, the plug works well again.
-some plugs had gray or allmost transparent white growth deeper in the filament, starting at about halfway of first coil. Especially the grey is very difficult to scrape away, partially because it is not possible to use so much force further away from spot welding. Whiter one is very hard, like glass, it chips away quite easily.

To prevent heat from escaping from the filament, I made a following experiment (picture). Ideally the plug body should be something else than whatever mild steel it is, like titanium, but I don't know how the welding would work then.. I'll try to find some time to test the plug soon, if I find any difference from standard plug.

L

[Derek Barry]

  500-1000, at which point it will start losing power. It should *never* blow. Unless it is SIG or you add Armor-All, and then you may lose power in about 50 flights as the plug develops "taters".


    Brett

500-1000??? I never get more than 20-30 per plug. I have used an exacto to scrape off the taters, which got me another 10-15 flights before they came back. I don't notice much if any drop in power but the engine gets harder to start as the taters grow.

Derek

[Brett Buck]

500-1000??? I never get more than 20-30 per plug. I have used an exacto to scrape off the taters, which got me another 10-15 flights before they came back. I don't notice much if any drop in power but the engine gets harder to start as the taters grow.

Derek

  SIG, I take it?  Because that's pretty much exactly what I was getting with SIG. It varies from engine to engine, too. The engine you got from me was one of the better ones in terms of taters. Bill Fitzgerald's engine (which I used at the 99 NATs) would go about 15 flights, and then the power would start fading. When I first installed it, I did about 5 flights and figured I would go back to the 40VF for more power. Then I saw the glow plug with a tater almost filling up the hole where the wire goes, changed it, and massive difference.

   All of that went away completely when we went to Powermaster.

   Brett

[Mark Scarborough]

It's a profile Oriental.
I don't think it has a severe vibration problem. The wing to fuse joint shows no signs of stress. It doesn't feel too 'vibratey'.

I was having a problem with the engine run about half way through the flight. It just sped up and ran way. Fuel foaming was diagnosed. I did fix a tank mount and added the ArmorAll. The fuel has no anti-foam ingredients that I know of. It is by RedMax and I didn't spec any anti-foam.

that sounds like a heat problem to me.
I think the solution for this is a few ounces of castor to help control the heat in the motor

[Derek Barry]

 SIG, I take it?  Because that's pretty much exactly what I was getting with SIG. It varies from engine to engine, too. The engine you got from me was one of the better ones in terms of taters. Bill Fitzgerald's engine (which I used at the 99 NATs) would go about 15 flights, and then the power would start fading. When I first installed it, I did about 5 flights and figured I would go back to the 40VF for more power. Then I saw the glow plug with a tater almost filling up the hole where the wire goes, changed it, and massive difference.

   All of that went away completely when we went to Powermaster.

   Brett

Yep, Sig. I get more flights using synthetic but it's still no where near 500. I have not tried Powermaster in years but maybe it's time to try again. I always felt like I needed to run a higher nitro Powermaster to get the same run as Sig. As of late I have been upping the nitro in Sig, the more I add the better it gets. My baseline is 15% now...

Derek

[david beazley]

Armor All works really good on motorcycle seats and automobile dash boards...not for the inside of engines!

Randy Cuberly

Dash boards, yes, motorcycle seats, I'm not a fan.  When I had my BMW R75/5 I used it on the seat once but I thought it made it too slippery and didn't like it.

[Steve Helmick]

Pre-VP ownership, Powermaster was known to be lower than rated in nitro content. VP bought them, and corrected that problem, but added some dye to make it purple, which caused finish tinting problems. They're supposed to have corrected that, too.

I've run a lot of Powermaster and Wildcat, neither seemed to cause any problems with potatoes or yams. I've never added ArmorAll for any reason, and only one time had an obvious vibration issue...caused by the fuel tank being loose. I always use Thunderbolt glowplugs, most often the old 4-Cycle variety, but sometimes the idlebar ones. One will usually work fine for the whole season, usually multiple seasons. Once, I had one not work come Spring...but only once.

If your glowplugs are "burning out" frequently, look for internal wear, typically on the backplate from pushing on the electric finger and having worn out the wear washers behind the prop driver.  Aluminum shavings do that, for some reason.   Steve

PS: Also not a fan of ArmorAll on motorcycle seats. Used it once on my dirt bike seat and tank, and almost slid off the back...

[Brett Buck]

Yep, Sig. I get more flights using synthetic but it's still no where near 500. I have not tried Powermaster in years but maybe it's time to try again. I always felt like I needed to run a higher nitro Powermaster to get the same run as Sig. As of late I have been upping the nitro in Sig, the more I add the better it gets. My baseline is 15% now...

    The 500 is just a WAG, I have had only one outright failure (apparently dinged when a bit of chipped bearing flew out, since it happened simultaneously with the engine suddenly sounding like a coffee grinder). Otherwise I will change the plug every few years just on principle, and I can't really point to any degeneration in performance.

    Don't worry about the nitro now. For a while, the old pre-VP Powermaster was the same as SIG, but later they snuck down the nitro to maybe 7-8% for the "10%". VP fixed it, and it's back to full power now. Even if it wasn't, you just pick whatever you need and ignore what it says on the can. I routinely run the 15% VP Powermaster in the midwest. It was a little jumpy the last few years when it was cool, but really good when it was hot.  I have occasionally gone down to 12.5%.

     I generally take 3 gallons of 15, 2 gallons of 10%, and a can of YS 20/20 to I can mix anything from 10 to 20. I seem to recall using 17.5 for a few really hot days and have run YS20/20 for tests. YS 20/20 straight out of the can is one of the tricks for flying at Tucson and Ted ran it at the 2004 WC.

   As long as you stay away from the 4-2 break, you can more-or-less run whatever nitro you want and not have to worry about compression. If you are attempting to run across the break, then, you might have to play off the compression and the nitro to get an acceptable mix of boost/brake and overall power. Every time I tried it, I found it a lot better to have lots of nitro and compression and no break, VS, less nitro and adjusting the compression for an acceptable boost/brake. It also needles very nicely with more nitro.

     Brett

[Howard Rush]

It is by RedMax and I didn't spec any anti-foam.

I'd try a different brand. 

[Dan Berry]

Well, I finally pulled the plug. I cannot see anything out of whack. It's a good shape, shiny and I see no spuds. And it lights up just fine.
I might get to fly tomorrow.
Decisions, decisions.

[Skip Chernoff]

While we are talking about fuel and glo plugs what I don't understand is why most folks don't mix their own fuel? It's so simple and that way you know exactly what you've got. I've been doing it for the last 40 years or so. I don't add any additives,don't believe in them.

One other thing....unless you are mixing your fuel in larger quantities buying "PowerMaster(very good fuel) is cheaper. I just like knowing what I have.....Skip

[phil c]

There are tons on non-silicon antifoams available, but might be hard to get in small quantities:  https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma/Product_Information_Sheet/a5757pis.pdf   and others.  It may take a lot of experimenting to find the right one.  Anti-foams can be very finicky.

Foaming can happen from other problems than a wiggly front end.  Both the old Supertigre and the OS style needle valves can resonate with the engine frequency and form bubbles right in the needle valve.  It's highly dependent on how tight the valve is cinched(ST) or how much it is worn(0S).  OS and Enya style needle valves can often draw air in through the threads(can happen on other designs too).  An o ring or a short piece of fuel line can provide a seal over the exposed thread.  They can also occasionally draw air around the needle(its a press fit) which require a bit of soldering on the outside to fix.

The plastic cap thingies a lot of people use to cap vents can also leak enough to mess up a uniflow tank.  They are more a slip fit, rather than the press fit of a piece of fuel line.

[John Leidle]

    I go along with what Phil said about the needle shaking things up. Way back I had a few  ST .51s     #3 just wouldnt hold a setting I tried every thing. One day I grabbed the needle to richen it up & it goes flat into a solid 4 cycle I let go & back into occilationing 2 & 3 cycles.. grab the needle & a solid 4 stroke.  I installed a different NVA & the engine was great .  Not all NVA are created equal.
  John

[john e. holliday]

Depending on brand of needle assembly a piece of fuel tubing or Teflon tape does miricals.

[Brett Buck]

    I go along with what Phil said about the needle shaking things up. Way back I had a few  ST .51s     #3 just wouldnt hold a setting I tried every thing. One day I grabbed the needle to richen it up & it goes flat into a solid 4 cycle I let go & back into occilationing 2 & 3 cycles.. grab the needle & a solid 4 stroke.  I installed a different NVA & the engine was great .  Not all NVA are created equal.

  Ted told me about that one, but I think he heard it from Big Jim. I had similar issues a few times. The problem is that the ST needle is suspended from the very end of the threads in the spraybar. In some conditions it resonates like a tuning fork. The solution is to tighten the collet until you can barely move the needle.

    Brett

[John Leidle]

   I try to do just that  but in that one case the NVA  was a dog so I sent it to the metal scrap yard.  It wasnt a ST NVA  some off brand that fit ( The old John , trying to save a buck ).  It only happened that one time.
     John L.

[Steve Helmick]

While we are talking about fuel and glo plugs what I don't understand is why most folks don't mix their own fuel? It's so simple and that way you know exactly what you've got. I've been doing it for the last 40 years or so. I don't add any additives,don't believe in them.

One other thing....unless you are mixing your fuel in larger quantities buying "PowerMaster(very good fuel) is cheaper. I just like knowing what I have.....Skip

It's not easy to source Nitro Methane for a lot of folks. Good Methanol can also be a problem to obtain. Back in the late '60's, it wasn't nearly as difficult. We had a source of good Nitro and Methanol pretty close. Not easy now, so our solution is normally to buy some quality fuel brand and fiddle with it by adding castor or (in my case) Randy Aero's "snake oil". "Aero-1", I think is his name for it. Better than using LiPo batteries, anyway!  Steve   

[Fredvon4]

In the USA Nitro gallon jugs are a mouse click or three away at Torco on e-bay...a bit pricey for folks who blend and burn a LOT of fuel

http://www.ebay.com/itm/like/141965943333?lpid=82&chn=ps&ul_noapp=true

I see price has increased since I bought a gallon earlier this year

I have all the components to blend.... some of my blends start out as local sourced lower Nitro and oil content fuel making the quarts of oil(s) and Gallon of Nitro go a long way

[John Leidle]

   I go along with what Fred said about buying the components from Torco  I dont remember the oil  if they sell it but they do sell the other stuff. I tried  Torcos fuel in my IC engines last Spring & couldn't be happier. The local hobby shop quit bussiness & the other one that sells Wildcat wont get Byrons for me so I tried Torco & its very easy to make the sale on Ebay.
                 John

[Carl Cisneros]

I have been using the Odonnel brand plugs in all my racing monos and hydros over the past 30 yrs. and
I started flying CL again about 2 yrs. ago and am using them as well in all
my nitro burning planes. I could not be happier. As of this writing, I have not had to replace any plug to date.  Odonnel number   ODO 008

My fuel is a home brew of 10% nitro and either 22% oil (50/50 mix) or 10% nitro 25% castor depending on the motors
the fuel is used in.

Just a bit of info as to another brand that can be used other than the ones mentioned here on the thread.

[john e. holliday]

Where do you get the Odonnelplugs?

[Steve Helmick]

Tower...and it's "O'Donnell". They sell fuel, too, but basically they're an R/C car company. It'd be interesting to know who makes their glowplugs, assuming that they're outsourced. Might be Ohlsson Corp., or PRC, who knows? Anybody have a contact at Ohlsson Corp., to ask what brands they make? They make many of the US brands.    Steve

http://www.towerhobbies.com/catalog/2011/pdfs/1001064-tcat-p208.pdf

[Carl Cisneros]

I get mine from the local hobby shop.
They carry model racings cars and have a good selection of glow plugs.

you can also get them from hobbytown usa.

also another good HOT plug is the McCoy # MC-59 Long plug.