Constant speed C145 prop

How to keep the Cessna 170 flying and airworthy.

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Jr.CubBuilder
Posts: 517
Joined: Thu Aug 12, 2004 10:33 pm

Constant speed C145 prop

Post by Jr.CubBuilder »

Does anybody know of a constant speed setup on the C145 for the 170?

The reason I ask, a while back I had my prop repitched and when I took it off I noticed what looked distinctly like a knock out plug on the end of my crank. On another occasion I was asking a mechanic what the cover plate on the top left (facing the motor) front of the block was for, he just grunted and said something about it could be for a fuel pump(?). Then the other day I was bored flipping through the bundle of TCDs and ADs etc. that came with the plane. In the part on the motor it indicated that there were a couple models of the C145 that had provisions for a hydraulic controlled propellor using engine oil. Presumably I thought that ment a hollow crank, and provisions for a govenor to mount to block by the propellor. Maybe this subject has already been beat to death but I'm not finding anything with a search that looks relavent.
zero.one.victor
Posts: 2271
Joined: Tue Apr 23, 2002 12:11 am

Post by zero.one.victor »

The cover plate you're talking about is to cover the fuel pump mounting pad. The engine-driven fuel pump was used on the 1948 (ragwing) 170, but not on A's, B's, or 172's. Also used on Swift's on the C-125 & those converted to the C-145/O-300. Don't know about the Aeronca Sedan, but I doubt it.
The hydraulically-controlled props were only used with the C-145-2H & O-300B engines. They had a dampered (as well as dampened) crankshaft. A small lever on the LH crankcase, just about oposite the location of the fuel pump pad, controlled the oil flow to the propeller.
Check your type certificate data sheet, there are 2 controllable props listed, a Macauley & a Sensenich. There is also a variable pitch (automatic, in other words non-controllable) prop listed, the Aeromatic. As far as I know, all three are long out of production. I have to assume that they didn't work any too well, or at least sell any too well, or else they'd still be with us.

Eric
Jr.CubBuilder
Posts: 517
Joined: Thu Aug 12, 2004 10:33 pm

Post by Jr.CubBuilder »

Hmmm, it's to bad there isn't a CS prop solution for the 170 without having to change the motor. The climb angle I could get with the seaplane prop before I had it pitched up was great fun, but a cruise of 85 was just too slow. Now I've got a 51 on there which climbs fine, and a cruise of 100-105 which seems like a good combination for here in the Cascades. It sure would be cool though to have a cruise of 130, the same climb performance that I have now, all with the 6-7gph fuel burn. Oh well that's just my wishfull thinking, and if wishes were fish................
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