RunRyder RC
WATCH
 1 page 761 views POST REPLY
HomeAircraftHelicopterEngines Plugs Mufflers Fuel › Flameout Causes?
06-19-2014 02:06 AM  4 years agoPost 1
Rob43

rrKey Veteran

Midland, MI USA

My Posts: All  Forum  Topic

I was flying the X50 last weekend, and on second flight, engine popped. I was just sure it was a seizure, hole in the piston or something bad. Landed safely. I have a Venom Digital Temp monitor (not ideal since the thermocouple is exposed to the cooling air) and in the few seconds it took to walk out to where the model sat, it read 340F! Oh No!

Back in the pits, I just let it cool off. A few mins later, I put the starter on it to see if compression remained. To my amazement, it was normal! I checked all fittings for a leak. All was good. No leaks, good pressure, fuel delivery was proper to the carb.

I refilled the tank (was about 1/2 full, and running stock header tank) and fired the engine. Fired right up without issue. flew another 1/2 gallon or so that afternoon, all things seemed great.

Plug had also looked fine, except the coil was severed. No surprise there. It was a nice bronze color and slightly wet looking.

What else could explain a sudden overheat and flameout like that? I presume whatever caused the overheat, damaged the plug. I assume something caused it to go lean all of a sudden. The filter looks fine too. Maybe simply an air bubble trapped in the fuel line to the carb?

I removed the engine and dismantled it. Everything looked fine. No really significant evidence of lean running.

Any thoughts guys?

Rob

PM  EMAIL  Attn:RR  Quote
06-19-2014 02:37 PM  4 years agoPost 2
datidun

rrKey Veteran

N Ireland

My Posts: All  Forum  Topic

When last did you change the battery in the Venom,at that temp the engine would have blown up,get yourself a bubbless fuel filter,no air getting to the carb,peace of mind,for the next flight.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-19-2014 05:50 PM  4 years agoPost 3
mustang67ford

rrKey Veteran

Central Pennsylvania

My Posts: All  Forum  Topic

Possibly some silicone from the muffler broke loose and shorted the plug? I had that happen. Will a shorted (power lead goes to motor case) remote glow plug cause the motor to shut off?

Team HeliProz - Retired
AMA #513507
IRCHA #4011

PM  EMAIL  GALLERY  Attn:RR  Quote
06-19-2014 06:05 PM  4 years agoPost 4
Rob43

rrKey Veteran

Midland, MI USA

My Posts: All  Forum  Topic

Thanks guys.

Already have bubbeless clunks in both main and header tanks. No observed stuff in the filter either. Only vapor/air-free method of fuel delivery is the bladder. Period. No other devices are "fuel proof"...LOL.

The remote glow only operates during starting. I think it glows the plug for 12 seconds and shuts itself off, which means nothing is in effect after that. The ground wire was still in-tact and secured, as it fired the engine properly afterwards.

My only other suspicion is fuel itself. I had just a flight or so earlier topped off the tank with Rotor Rage 30 after running Cool Power 30. I wonder if an incompatibility exists between these two fuels? If so, it would explain it.

The next question would be how to flush fuel from the system, when switching over to an alternate product, as I will soon burn the rest of my Rotor Rage and have to switch back to Cool Power.

Rob

PM  EMAIL  Attn:RR  Quote
06-19-2014 06:19 PM  4 years agoPost 5
Tyler

rrElite Veteran

Chicagoland area

My Posts: All  Forum  Topic

You are making this too complicated.

Fuels work, regardless of brand if you know how to tune an engine.

Glow plugs sometimes fail, but most often when the engine is not tuned properly.

Change the plug and retune using the owner's manual from the engine.

Don't overspeed the engine.

The more you change at once the more difficult it is to get the model flying well again.

Glow plugs are consumables.

Don't ever use silicone for anything on your model, especially for mufflers. Glow plugs hate silicone, and so do helicopters.

Enjoy things that money can buy IF you don't lose the things money can't buy.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-20-2014 01:51 AM  4 years agoPost 6
GREYEAGLE

rrElite Veteran

Flat Land's

My Posts: All  Forum  Topic

For what it's worth :

Hard to believe but the Poly Jug is a permeable plastic resin, moisture can go thru it and visa versa. When you take them from a air conditioned cool basement to a Hot Warm environment you can get moisture condensation in the fuel itself.

Why shaking a Jug with FIZZy Bubbles tells you it got a LOT of good stuff - Just like shaking a jar of moon shine - REAL = No Bubbles it could be flat. In the chemical industry they actually have desiccant in either a sock or sponge form to pull moisture out of high solvent base's. Most of the product's are kept under a inert gas blanket.

You may have swallowed a bit of water

Why in the ancient of day's : When mixing contest fuel on site for the event, they used what is known as a Sling Hydrometer. Temp and Humidity and amount of Nitro.

Far as a weird plug issue " I have also reached the 340 degree club "

Plugs are manufactured in actually two pieces

Once had a plug in a plank that the insulator around the pin, broke it's press fit seal -the plug absolutely had the Motor jinxed

Once we could see bubbles forming around it : " the pin" - that sucker was toast !

I put it in my used plug collection - for loan too some unsuspecting

greyeagle

PM  EMAIL  GALLERY  Attn:RR  Quote
06-20-2014 02:32 AM  4 years agoPost 7
RaptorMan23

rrKey Veteran

Sioux City, IA

My Posts: All  Forum  Topic

Ive witnessed his 340+ degrees, its almost rediculus that the ol girl still runs. Runs stronger than most regardless of the beating

If you only have to bend over once to pick it up it's a good landing.

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
06-20-2014 02:08 PM  4 years agoPost 8
Brian C

rrNovice

Houston, TX

My Posts: All  Forum  Topic

Random Engine Flameout
You did not say which engine model is causing problems,
but when the rear bearing is failing and making metal
flakes, they sometimes hit the glow plug damaging the coil.
When this happens engine my stop for a split second and
recover or die. Common in rear bearings of 50 size engines.

Brian

PM  EMAIL  Attn:RR  Quote
06-21-2014 01:02 AM  4 years agoPost 9
Rob43

rrKey Veteran

Midland, MI USA

My Posts: All  Forum  Topic

I appreciate all the comments, guys.

I am not sure how I am making too complicated. Temp monitor? I suppose so. I will check with a IR probe next time. I did use high temp RTV to seal the header to the engine, but there was nothing in the filter. And I was judicious with the application.

I was mainly asking if mixing fuels could have led to the overheat scenario. Of course, fuels work...but I have other experience in the manufacturing industry that some lubricants can be incompatible, and cause weird problems.

Engine model is a Redline 53H. O.S. 60L Carburetor with an intake manifold adapter. Works rather well, at least as best I can tell.

On the rear bearing, it looks like new, and is about 2 gallons usage so far. I did check for a loose carburetor fit last time I had it out, which was after this incident. Previously, I had some fuel leakage (with no flight effects that I could detect). I checked to make sure the carb throat o-ring was compressed and the carb secure - as it's only held on with a set screw. It was fine. The cause for leakage was the pressure fitting on the carb came loose. But that was a week prior to this incident. I'd corrected it before this incident. I checked it again, when this happened, and it was nice and tight. As was the muffler pressure fitting.

I've stored my fuel in the garage. So, it stays close to whatever the conditions are outdoors when I fly, and I then keep the tank full between flights. I like to displace all the exhaust vapor from the tank with a fill-up. Hoping this was a one-time thing. Amazed it did no apparent harm.

Rob

PM  EMAIL  Attn:RR  Quote
06-21-2014 02:02 AM  4 years agoPost 10
Tyler

rrElite Veteran

Chicagoland area

My Posts: All  Forum  Topic

340 F on the ground after a flame out doesn't exactly mean that the engine ran at that temp. Engines heat soak and increase in temps as the engine sits without the flow of cooling fuel and oil.

Enjoy things that money can buy IF you don't lose the things money can't buy.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-21-2014 05:49 AM  4 years agoPost 11
GREYEAGLE

rrElite Veteran

Flat Land's

My Posts: All  Forum  Topic

Just to make more info available : Since I'm kinda a motor junky - Nothing I do is normal either ! What I have experienced in Heat and behavior. Assume nothing is ever standard.

Please NOTE: Synthetic's are SO GOOD they can actually mask a problem - so I do,- dope my fuel with a touch of baker's AAA and I run straight 10% or 15 % for cost. I also run a vendor I can trust - No - Hype just very traditional straight Q.C.s. Lube engineering is witchcraft.

My T- 52 has got every piece of experiment Iron hung on it - It's a Pig in weight. I also Run a Heavy Nicad, and a spare pinion and jack shaft off of it, extra bearing's for the shaft and it's frame , a C- Volt, a Golden Orb of Ra, and a real time thermocouple K wire actually direct touching the cylinder wall face - Hard contact - out of the air stream. I also do Not run a governor. Depend solely on my ear and curve's. Another discussion.

It also has a small poly air dam installed behind the fan - between the cross frame's to stop the wasted gate air from spilling out the back. The carb has a rubber BruLine 3X O.D. ventury over the top - No Filter.

The Bird is NO- Ballerina - Its a Iron Pig : But a test bed. It's also got a pretty wicked top end once up on the pipe and it feel's like running evil. It can get the nose bobble if your letting it get cooking.

My temp's behave actually back wards - I land pretty HOT - 300 or easily above after reaching operating soak - then can watch it drop - and listen to it cross over on the pipe to the fatness as it cool's and spin's down -I must wait for the cool down and cross over. It will actually run stinking too cold at idle - You wouldn't believe it un less you witnessed it.

Run Up is the same - Start - Make Hover - Gas the place out BAD - as it drip's -- sound's awful till it comes to Heat and wait for it --- you will hear it coming on. Once it clears and the Pipe crosses over - the RPM's just keep climbing - then out to do lap's and circuit's. It's a pig and hate to try to auto it - spooked as the motor may not recover on demand.

We actually easy out Rpm'd the original MA 'Tach ?? 2000 ?
We finally re curved it too de- tune it - It got a bit spooky -- but then it also ran the best. It has little carb dwell. Either you got it or you don't.

But it's carrying a ton of weight !! and running a bunch of mechanical drag - Lot of my initial problem's was too Small of a pipe Volume for the Motor - and a Carb which has a wicked dead spot do to throat size and cross over . It can't breathe - but the motor is begging for air.

Friend finally beat me senseless into a larger volume Pipe and it Helped a LOT . Also had to cut & install Brass Muff Gaskets do to the temp and chasing bolt tightness. It run's clean - But it will burn off a exhaust schnozzel after a while.

This motor has almost the same frame as the Red Line -and came out just 9 mo's prior - I knew the frame when I saw it - where the original design came from -- Larger bearing's - touch heaver crank - case webbing and weighs 4oz More right out of the box and a massive head heat sink. I had to carve the frame air dam in front. One giant heavy heat sink. Run's cold

I would NOT Recommend it to the Buy and Fly Guy's. It would defeat em.

Part of the issue could be your PIPE Volume is a touch too small in volume when it start's asking for air and is restricted. -
Mine had the same behavior. It will suck it self shut for air & Starve.

I'd like to pick up another and go thru a few of my Rossi Carbs and see if I can jump it to a bigger throat - maybe a full metal head .
Lot of them got tossed when they came out.

It's fun but a Iron Duck

greyeagle

PM  EMAIL  GALLERY  Attn:RR  Quote
06-21-2014 12:54 PM  4 years agoPost 12
Rob43

rrKey Veteran

Midland, MI USA

My Posts: All  Forum  Topic

That's crazy cool stuff, Greyeagle. Can always count on you for the extraordinary!

I understand the heat soak thing, at least at a modeler's level. I've noted that when I land to check backplate or adjust needle, it's cool to the touch mostly. Immediately after I shut the engine off, it begins to warm up. In this particular instance, it was definitely unusually hot. The stink of burnt oil was obvious, as was the backplate temp. Maybe it just got too hot from too lean of a low mix screw setting, and that is it. It probably didn't reach near that 340F temp in flight. Plug popping was likely just a plug popping, LOL.

Rob

PM  EMAIL  Attn:RR  Quote
06-21-2014 01:18 PM  4 years agoPost 13
goof2

rrApprentice

Bristol,CT

My Posts: All  Forum  Topic

+1 rear bearing possible problem.
When a good running engine starts acting strange usually rear bearing is the culprit.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-22-2014 03:42 PM  4 years agoPost 14
Rob43

rrKey Veteran

Midland, MI USA

My Posts: All  Forum  Topic

Understood. I will keep an eye on it. It has run great after that single incident, though.

Rob

PM  EMAIL  Attn:RR  Quote
WATCH
 1 page 761 views POST REPLY
HomeAircraftHelicopterEngines Plugs Mufflers Fuel › Flameout Causes?
 Print TOPIC  Make Suggestion 

 4  Topic Subscribe

Sunday, August 19 - 5:26 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online