New propeller

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TFF

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Let’s hold a second. Read this C150 instructions from here. http://rob.com/matt/manuals/150_sm_69.pdf

You have an O200. Still put TDC#1. The prop should end up in the same place when stopped but because Continental uses a back cylinder for #1,I screwed up thinking Lycoming.

O-200 tailwind is a rare beast these days.
 

Doran Jaffas

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Jun 25, 2019
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409
Will do.

Will do. So far I am very pleased. Flying again Sunday and Monday I hope. The cruise comes back with slightly higher RPM. Climb is " wow". Engine and propeller are within perimeters. Throttle back in high cruise to keep from over-revving the engine but even at it's highest the engine is still within spec and prop is .85 of mach.
Another note..
Keep us posted on the difference....jeff
Recently I went into a 2,200 ft strip. The landing I was sure about. The take off was quick due to the propeller. Even though it turns on the high side, I am going to keep it for the climb performance.
 

Doran Jaffas

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Jun 25, 2019
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409
Update to the propeller discussion.
I have been in touch with Ed Sterba and sent a check for one of his propellers. Though I am reasonably happy with the Prince propeller it is a little flat and my engine is over speeding slightly at full throttle. I ordered a more aggressive pitch from Ed Sterba and I should receive that before the end of march. At that time I will bolt it on and check the performance and if I'm happy with that propeller I will be selling my current Prince propeller at a greatly reduced rate if anybody is going to be interested. It originally came off a c85 and works well as a climb prop for the 0200 but I'm looking for a little bit more cruise.
 

Dan Thomas

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Sep 17, 2008
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Nobody seems to have reasonable instructions on how to mount a prop. The Cessna 150 manual is very hard to understand.
Not so hard.

1613931171410.png

So you turn the crank until the #1 cylinder (that's the rear one on the copilot's side) to TDC on it compression stroke. The TDC mark o the crank flange will be lined up with the crankcase seam UNDER the crank, not above it. Then you hold the prop vertical in front of the flange and rotate it to your right until it lines up with the first available holes. That will put it around 30° off the vertical, or at about one o'clock and 7 o'clock. That makes the impulse fire at about that spot or a little bit earlier, ideal for hand-propping, and it minimizes vibration. You don't want that impulse firing up high; it risks serious injury. Hand-propping is dangerous enough as it is.

In that position the prop will stop at about ten o'clock-four o'clock. That's where the pistons want to sit, with one about halfway up its compression stroke and another about halfway down its power stroke, since the dead engine doesn't fire and the power-stroke cylinder still has compression pressure in it. The other two cylinders will have an exhaust valve open in one and the intake open in the other, so no pressures.
 

rv7charlie

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Nov 17, 2014
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To finish the 'clocking' thought, those instructions typically are specific to hand propping safety; many Lycs seem to run a bit smoother with the prop clocked in line with the cylinders at TDC.

I had an RV4 with O320/160 HP that would shut down with the prop vertical, even though it was 'clocked' normally. Most of the time on shutdown it would stop near TDC on a compression stroke and stay there. (Yeah, I thought it was strange, too.)
 

Dan Thomas

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Sep 17, 2008
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To finish the 'clocking' thought, those instructions typically are specific to hand propping safety; many Lycs seem to run a bit smoother with the prop clocked in line with the cylinders at TDC.

I had an RV4 with O320/160 HP that would shut down with the prop vertical, even though it was 'clocked' normally. Most of the time on shutdown it would stop near TDC on a compression stroke and stay there. (Yeah, I thought it was strange, too.)
Depends on how the prop is drilled. The Cessna 172 manuals (Lyc versions) tell you to do the same thing with the prop as the 150 manual does, and you can't install it straight up-and-down on the flange. The prop's holes are in the wrong place for that. The holes are 60° apart.
 

rv7charlie

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Not what I said; I said you can install them *horizontally*, with #1 @ TDC. Only problem would be the Hartzell CS props because not all six holes are drilled in the prop hub.

I said mine would frequently *stop* with the prop vertical, which was right on TDC of the engine. Just a weird combo of rotating inertia & compression, on that particular engine.

Here's a web page detailing the much more complicated process of reclocking a Hartzell, on a 6cyl Lyc.
Clocking Of The Prop
 
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