Engine help, please?

[Rodney Kirstine]

Hi guys,

On the day that I ended up putting a hole in my piston, I had two glow plugs die, prior to the complete failure.  I rebuilt the engine last night.  The engine fired right up but as soon as I turned the Switchglo off, it would die immediately.  It didn't matter what rpm it was running at, as soon as I turned off the Switchglo, the thing would die instantly.  After about 1/2-tank of going through starting it, killing it, and restarting it... the glow plug went kaput.  Do any of you have any ideas what could be causing this?

Thanks!

[Darren Lee]

Which glow plugs and fuel?

[Rodney Kirstine]

O.S. #8 and Torco 30% heli blend.

[Rodney Kirstine]

After talking with one of my co-workers today, who has many years of nitro engine experience, he thinks I probably ended up with some aluminum on the glow plug.  Considering the fact that I scraped a chunk of aluminum off of the inside of the top of the cylinder head when I pulled it off, I bet he's right.  That chunk of aluminum looked like a little tiny aluminum cow pie and I bet some chunks of melted aluminum splatted onto the glow plug, as well.

[Rodney Kirstine]

Just to follow up... It looks like my friend was right.  I installed a brand new glow plug and it fired right up.  I turned off the Switchglo and it continued to purr.  After running one tank through it, in keeping with my perfect string of crappy luck, my fuel pump broke and I couldn't fuel it up for another run.  Oh well, at least it runs now and it's still in one piece!

[flyalan]

Man Rodney. We have got to find you an exorcist!  Those demons keep returning. You are due for some good fortune for sure :-)

Cheers
Alan

[Mark Burberry]

I am with Alan on this one... You definitely are due for a good luck run now!

Glad you got the the engine squared away though.

Mark

[Bob Heybrock]

Hey Rodney,

Did you figure out why you holed a piston in the first place? I'd be concerned about that, what engine are you running, what are your needle settings and what altitude above sea level are you?

I'm running an OS .55HZ in my N5c with no problems but a local club member with the same engine (different heli) was going through glow plugs and burned it up on his second gallon of fuel. After discussing it with him he had his high speed needle way too lean and was messing around with the midrange needle.

I also stuck a 2 ounce header tank on mine and it seemed to regulate flow and create less mixture change during flight.

Good luck and let me know if I can help.

[Rodney Kirstine]

My friend at work thinks that it's more likely detonation, rather than it being too lean, that's causing my problems.  Right before it blew the hole in the piston, I went through two glow plugs back to back.  After my last post where I had replaced the glow plug and had a successful flight, I got a new fuel pump.  I went to fly last night and my glow plug was bad from that one flight.  I know I'm not too lean because I'm at the recommended needle settings and it's running so rich, it's just blubbering fuel and oil.  I went and bought a couple of OS no.10 plugs today and I'm going to give it a go with the colder glow plug and see how that goes.

[beans07]

Blowing plugs and holes in pistons is nearly always too lean. I have never seen pre detonation in a 50 or 55 sized engine. If there was was pre detonation your head and piston would be all rough looking.

You could also have bad fuel with not enough oil or possible water contamination.

Sent from my GT-I9305T using Tapatalk 2

[Rodney Kirstine]

I was only able to run two tanks yesterday before I had a ball link break and end my flying...  The colder glow plug was still working after both flights, so I guess that's something.   

[Chris Sexton]

What fuel are you running? I had troubles burning plugs I couldn't tune out. Matt recommended I tried cool power. Haven't burned a plug yet. Matt helped me set a baseline tune that I have had to touch.

No joke 2 gallons on that plug and tune. Love it.


Sent from my iPhone using Tapatalk 2

[Rodney Kirstine]

What fuel are you running? I had troubles burning plugs I couldn't tune out. Matt recommended I tried cool power. Haven't burned a plug yet. Matt helped me set a baseline tune that I have had to touch.

No joke 2 gallons on that plug and tune. Love it.


Sent from my iPhone using Tapatalk 2

I've been using Torco.  What's weird is that I burned three gallons of fuel with zero issues and then this started.  I will probably switch to cool power after I've burned this last gallon of Torco that I have because I found I do have a good place to get nitro, locally, for a decent price.

[Chris Sexton]

I was using wildcat before. Started having issues after burning a piston. Rebuilt. Took to Birmingham. Flew a couple of times no Issues. Was getting it ready for night flying and it wouldn't fire. I changed the plug, fired right up.

Matt flew it once to try night blades and immediately landed. Said it was way lean even though it had plenty of smoke. Sure enough, glow plug would not relite again. Change the plug again. Reset needles to Matt's recommendations. Swapped to cool power and flew the crap out of it. I am still running that same tune and the same plug! Birmingham was in march!


Sent from my iPhone using Tapatalk 2

[Chris Sexton]

Fuel can make a world of difference!


Sent from my iPhone using Tapatalk 2