Maiden Titan Hover After Overheat...

[Sgt_BF_Gunner]

Well finally got the Raptor Titan off the ground and hovering!!! I started last fall but was having problems with the clutch backing off the engine and into the clutchbell.

I got all that squared away and finally the weather is "cooperating (still cold and windy).

Yesterday I tried to get a hover. Engine was cutting out at over half throttle. From buggy nitro experince (or lack of) I thought the motor just has to break in. TThe bird has an OS50 Hyper in it. I ran it twice in the fall for a couple of minutes before the clutch unscrewed into the clutchbell.

So my intention was to idle the motor through a tank of fuel and "break in" the engine. I throttled up and down and finally got a little extra speed at just over half throttle. I wasn't too concerned, plenty of smoke and all sounded fine.

After the tank of fuel I checked and found the motor was screamin' hot! I checked with the temp gauge and it read over 300 degrees... The head had vibrated/melted(?) a little of the frame plastic and the remote glow plug connector was dangling (either solder melted or a cheap solder job to begin with).

Being a nitro newbie, I ASSUMED that the factory settings would be good and forgot to check the needle valve settings. As it turns out, the valve was set at 1/2 turn... OUCH!

I pulled the motor to check the damage and there was none really visible. From the muffler opening I could see the piston and all looked fine, nothing looked burned... I said myself a little prayer.

Today I opened the valve to 2 1/2 turns. The engine ran great but there was a bunch of fuel on the landing pad I had set up. I backed it down 1/4 turn and just left it for now. I only wanted to hover a bit and set the GY611 and break in the engine some more.

It seems to be running fine, and lots of smoke for now.

I have my fingers crossed but my overheat escapade probably cost me some of the engine's life. Just hoping that I didn't do too much badness to it's juju.

Man, what a difference hovering 4 feet of smokin' thundering heli versus my nice quiet and "small" T-Rex 450.

Anyone else have any "my engine should have been cooked, but wasn't" stories??

Thanks for listening!!! :shock:

-Gary

[vera]

Man, what a difference hovering 4 feet of smokin' thundering heli


:mrgreen:

I like it. I call it "skeeter control".

Your engine might be just fine but I like to run a tank through a new engine with the engine almost to the point of 4-cycling... and with no blades just to make sure it doesn't go anywhere in case I messed up.

[Sgt_BF_Gunner]

Yep, I know what you mean, I was definitely foggin' some skeeters. It was quite a spectical in the back yard. Kinda of like on the flight sim when you have the smoke turned up so high you can't see the heli.

Motor was luke warm, if that even, after hovering. Will start leaning it out slowly when I get to the field and have some room to fly it.

Just still have my fingers crossed, have learned a lesson and will consider it a heat cycle break-in. Yeah, that's what it was a heat-cycle breakin-in... And I'd like ya to meet my wife, Morgan Fairchild... :arggg:

What is to the point of 4 cycling? Really rich or really lean?

[WayneBrown]

4 cycling is rich to the point of missing a beat..
at 300F I'd say the motor will not last long, Accelerated bearing wear will be my guess at what will do it in. (too lean, no lube)

[Sgt_BF_Gunner]

I am not running the motor at 300F... I had the one incident of 300F...
I am running it at a proper temp now and still running rich.

I did not burn a hole in my piston for that one incident and inspected the engine and everything looked fine. I've seen the photos of other folks burned out pistons, etc.

I was wondering how much life I probably shaved off that engine for that one time.

Think the bearings cooked for one overheat? And how do you tell...

Thanks

[BarracudaHockey]

Also I personally would never run a nitro heli with no blades.

[redgiki]

Also I personally would never run a nitro heli with no blades.

Yeah, my bird doesn't perform to my expectations when set up that way. The climb rate really sucks.

:mrgreen:

OK, back on-topic: Yeah, the setting on my 32 motor out of the box was way too lean. Backplate temperature was uncomfortably hot, motor was really hot. I flew it that way a couple of times (smoke test seemed OK!), then started checking the temp and went "holy cow!". That's what I get for assuming this motor would be like every other motor I ran: too rich due to high altitude. Factory setting was WAY off from what I needed.

Now that I've richened it, the backplate is just warm to the touch (I can keep my finger on it right after a flight for 30 seconds or more without discomfort), and the motor is hot but not too hot. Feels about the same as the smooth-running .40-ish motors I fly on my planks. I need to twiddle with the low-end needle, some, though, because since my richening of the top end she has to idle surprisingly fast. Not fast enough to cause the clutch to kick in, but faster than I like.

Living at 5000 feet, too, results in weird motor issues. Most engines are way too rich at their factory settings due to lower air pressure here than at sea level. Of course, my .32 was the opposite. And at this altitude, it's not very strong. Maybe I'll replace it with the OS .46FX-h I have sitting on the bench right now...