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Inverted glow help!!!!!!!!

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Inverted glow help!!!!!!!!

Old 02-27-2007, 08:17 PM
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Zort86
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Default Inverted glow help!!!!!!!!

Hey guys, I am looking for a little advise.
I have a glow engine inverted in a Hanger 9 P-40 and I have been having a hard time getting it started. Once I get it running it seams to run fine, but trying to get it started is a real pain.
If any one has any sugestions please let me know, I would love to get this solved, it is such a nice flying airplane.

Thanks for all your help.

Oh, it has a SuperTiger .90 with a MPI onboard Glow.
Old 02-27-2007, 08:28 PM
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LANNYBOB
 
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Default RE: Inverted glow help!!!!!!!!

i have the same problem with my st 2300 the reason is that the fuel has to run uphill against gravity and the only way to overcome that is to
start the plane on a stand upside down. i sometimes have to take the glow plug out and squirt fuel into the piston area, then it starts right up.
it blows i know.
Old 02-27-2007, 08:31 PM
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Rcpilot
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Default RE: Inverted glow help!!!!!!!!

Move your fuel tank so that the center of the tank is even with the spraybar in the carb.

Tune it for the best idle you can get. It should be able to idle indefinetly mounted upright or sideways. I'd be impressed to see an inverted 2-stroke idle for more than 2 minutes if it didn't have onboard glow or a regulator on it. So, tune it as absolute best you can.

THEN put the glow unit on it and adjust it to just barely come on so the engine stays running at idle.

Get it tuned right first. Put the glow unit on to hide the sin of an inverted 2-stroke. It's the best way to tune it all. The low speed needle effects the high speed needle. If you tune the engine with the glow lit--you'll get crazy needle adjustments on the high end. With a glow unit, you can get the low end tuned so sloppy--oh, it'll still run because you have the glow on it--so sloppy that it effects the high speed needle adjustment. You end up chasing your tail with whacky needles.

#1 Move the tank
#2 Tune it without any glow driver assiting it. Tune it good.
#3 Install the glow unit and adjust it to only come on when you need it. If you tuned that engine good--you'll need the glow unit on for a max of 3-4 clicks from idle. Beyond that, the driver should be off and the engine running all by itself.
Old 02-28-2007, 08:33 AM
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Zort86
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Default RE: Inverted glow help!!!!!!!!

Hey, thanks for the advise. I think the tank and the spray bar are even or the tank is a bit higher, but I am going to double check to make sure.
Also I will make sure i get the setting just right.
I will try this this weekend, I will let you guys know how it went.

Thanks again
Old 02-28-2007, 11:14 PM
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Default RE: Inverted glow help!!!!!!!!

The tank can't be "a bit higher" It needs to be right on the button.

Look at it like this:
If your tank is centered on the carb spraybar--then no matter what attitude the plane is in----------the tank is always centered on the spraybar. If you fly inverted--the tank is centered on the spraybar. If you fly upright--tank is centered on the spraybar. Knife edge? Tank is centered.

The tank being out of whack is what causes a lot of the problems discussed on this forum. But, nobody ever wants to take the time or effort to rip out the factory tank support and make a new one to locate the tank properly. It takes about an hour to do it. A little glue, some sand paper and a razor saw is all ya need.

That and a desire to actually have it RIGHT--instead of kinda right. I'm kind of a nutball when it comes to stuff like this. I'll buy an ARF. Not too proud to say that. I like to build also. I LOVE to build. When I buy a new ARF--first thing I do is check out the tank support and do a "mock-up" on the fuel tank and engine while it's mounted up and bolted to the firewall. If it's not perfect, I rip it out and do it right.
Old 07-17-2007, 07:29 PM
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Default RE: Inverted glow help!!!!!!!!

I didnt realize that inverted engines were so finicky. I also have a Hanger 9 p40 Warhawk. It has a Evolution 61 with a bisson muffler. All of it is new. I cant keep in running. I thought at first my problems where because not only is the engine inverted, The muffler angles upwards before exhausting out of the two side pipes. Every time I think I've got it right, it dies. Ive had more dead stick landing with this plane than with all my others combined. Im using Wildcat 15%, I've used 10% and also FAI 0%. Just installed another number 8 os plug. At least the landing gear are holding up. Does anyone have any ideas or is this typical of inverted two strokes? Thanks.[:'(]
Old 07-17-2007, 08:31 PM
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Nathan King
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Default RE: Inverted glow help!!!!!!!!

I've got an airplane with an inverted two-stroke AND the fuel tank is a good inch above the carb. It runs fine, it took a long time to get just right. They will run ok, BUT the margin of error for the needle settings is VERY narrow. Also, try a hotter glow plug.

Two strokes are harder inverted than four-strokes because the glow plug sits at the very bottom. The oil can pool down there and cool down the plug.
Old 07-18-2007, 03:54 PM
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Default RE: Inverted glow help!!!!!!!!

Yes I realize the low speed needle is very sensitive. How Im tuning is at wide open, with the glow driver removed I slowly turn the high speed in (lean) until the engine runs at peak rpm. I then turn it back out until the motor loses about 3 to 4 hundred rpm (confirmed by my tach). The low speed needle is set at idle. There is a very small area where the engine runs fine. This area is about the range of a quarter turn. Anything outside of this and the engine simply wont idle. The best I've ever had is a idle for about 30 seconds, then it dies and fuel starts dripping out the carb. Once this happens, I have to remove the glowplug to drain the fuel from the plug. THe Hanger 9 p40 has the hole in the firewall where the bottle neck of the fuel tank fits through. This looks to be exactly centered with the spray bar in the carb. I do use a fueler valve which mounts between the carb and the tank. This shuts off fuel to the carb when you insert the probe while fueling. The valve is mounted about 1/2 inch above the spraybar. Im about to tear it back down to the firewall and remount the engine sideways. Yes Ill have the cylinder head sticking out the side of the cowl but at least then the exhaust will exit out the bottom. I hate to mess up the cowl but I'd rather it run correctly then to look cool. I can always just fly left to right and then come back right to left inverted so you wouldnt see the cylinder head, lol. Do you think a hotter plug might hold an idle better? What type of plug?
Old 07-18-2007, 04:24 PM
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Default RE: Inverted glow help!!!!!!!!

inverted engines always run better with an os'f' plug fitted.
Old 07-18-2007, 07:40 PM
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Default RE: Inverted glow help!!!!!!!!

One of these days some one is going to hydrolic a cyclinder clean off their new engine when it loads up with raw fuel. Raw fuel and a glow plugs do not work together it always pays to run your engine dry when you are finished with it or unburned fuel or excess oil will fowl your glow plug[:@] Always warm up your engine before flying and fine tuning bump and go does not work upside down .
Old 07-18-2007, 08:52 PM
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Default RE: Inverted glow help!!!!!!!!

ORIGINAL: bigchap

inverted engines always run better with an os'f' plug fitted.
Yes, that's what I was getting at when I said a "hotter plug". The "F" is the hottest and is what I run in my four AND inverted two strokes. Everything has to be adjusted perfectly and the engine warmed up. It takes some tinkering, it will pretty much stay once you have it. Except the few clicks either direction depending on temperature and humidity (overall air density).

RC Outlaw brings up a good point. Rotate the prop with your hand to make sure the engine is not hydrolocked. If you let your electric starter kiss your spinner when hydrolocked you will likely damage your engine.

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