What is this lever on my engine?

[TFA170]

So, I've got my new (to me) 1953 C170B finally. As I was crawling all over it again since I looked at it in early Jan, I noticed this lever on the crankcase near the front on the pilot's side. The picture is taken through the cowl opening on the pilot's side. It is safety-wired full up/aft (if it were cable pull as it appears).

What is it? If I move this lever forward, will I gain more power?

OK - the forum picture size restrictions are kind of silly and I can't seem to adjust my picture either offline or online, so since I am unable to embed a pic, here's a link to photobucket:

http://i279.photobucket.com/albums/kk14 ... ever_1.jpg

[fishdoc]

Looks like the obsolete ground adjustable prop lever I have on my O300B.

[bagarre]

Not ground adjustable but in flight adjustable.
That motor was a prerequisite for the Aeromatic propeller.
Fairly rare to see

[Bruce Fenstermacher]

You either have a C-145-2H or a 0-300-B. As stated the lever is moved full one direction or the other in flight and that allows oil to flow through the from of the crank to a prop that would use the pressure to activate something. Only two props are know to use this and they are rare as hens teeth. The Aeromatic used it to over ride the weight system that controlled the plade pitch and there was/is a two position McCauley prop that uses it to change pitch from low to high and back.

Look on your engine data plate. If it is a 0-300-B, it is not a legal engine for any 170 according to the TCDS. So if you have no other basis of approval like a appropriately signed 337, you need to consider buying the Associations STC which will make the installation legal.

[cessna170bdriver]

Not ground adjustable but in flight adjustable.
That motor was a prerequisite for the Aeromatic propeller.
Fairly rare to see

Actually, the Aeromatic didn't require hydraulics and was usable (not necessarily legal) on any engine it would bolt up to. It used propeller loads and counterweights to automatically shift between high and low, sometimes at a less than opportune time...

The photo depicts an engine set up for the 2-speed McCauley hydraulic propeller. Actuating the cockpit control shifted it between low and high pitch. There is no governor, so no in-between.

[bagarre]

Not ground adjustable but in flight adjustable.
That motor was a prerequisite for the Aeromatic propeller.
Fairly rare to see

Actually, the Aeromatic didn't require hydraulics and was usable (not necessarily legal) on any engine it would bolt up to. It used propeller loads and counterweights to automatically shift between high and low, sometimes at a less than opportune time...

The photo depicts an engine set up for the 2-speed McCauley hydraulic propeller. Actuating the cockpit control shifted it between low and high pitch. There is no governor, so no in-between.

This is true for a normal Aeromatic. No external controls were needed.
But the one that was approved for the 170 had a hydraulic over ride as Bruce mentioned to help performance at higher altitudes.
The TCDS requires the -2H motor when using the Aeromatic with the override. The Prop is also called out with the F200-H hub (H for High Cruise hydraulic over ride option).

There is currently no approval for a standard Aeromatic on a 170.

[blueldr]

If that engine was mine, I wouldn't be concerned about the legality of that engine on that airplane or spending any money for a STC. I'll bet there isn't one piece of FUZZ living that is ever going to check on it. It has probably been on one or another C-170 for sixty years or more.

[TFA170]

I'm not worried about the legality, it is a C145, so it must be the 2H as described which is in the TCDS. The s/n of the engine is in the first page of the original logs and is the same serial number on the last page of the current logs. I believe the engine to be original to the plane and legal.

I did find the TCDS and it appears the McCauley prop in question is this one:

McCauley two-position controllable, hub 2B36C7, blades
78K-2 (Models 170A and 170B landplane and skiplane
with C-145-2H engine)
Pitch settings at 30 in. sta.:
low 13°, high 17.5°
Diameter: Not over 76 in., not under 74.5 in.
Item 108 with seaplane lip and Item 402(j) required. (cowl mod & operating manual)

I would imagine this is a pretty rare prop...but if anyone has one lying about they don't want to fool with...let me know!

[blueldr]

I have never even seen one of the McCauly two position props, but I can't help but think I would have loved to nave one on my '52 C-170B when it had the O-300 engine.
When I went through the basic phase of flight training back in 1943 in the Vultee BT-13, the 450 HP P&W R-985 engine was equipped with a Hamilton Standard counter weight type controlable propeller that was set up as a two position propeller with only an oil control valve rather than a governor for prop control.
The standard practice was to use low pitch for take off and high pitch for cruise. We used to get about 1900 RPM in cruise with the prop in high pitch.
The engine was red lined at 2300 RPM. Being the clever young devil that I was back in my wasted youth, on a cross country training trip I figured that I could get more horsepower and thus more speed if I could get a couple of hundred more turns a minute from the engine. That way I would beat the other guys around the course and be a considerably hotter pilot,
As a result, I became the prop governor by jiggling the prop control lever back and forth to control the engine at about 2150 to 2200 RPM. The old BT-13 arrived back at the home station with it's tongue hanging out but I beat everyone elses time. My instructor thought I had cut the trip short, but I had landed as required at the far end and they had checked off my number. I never did tell my instructor what I had been doing because I thought they might bust me out.
The next phase of training was Advanced Training with the North American AT-6. It had a P&W R-1340 engine with the same type Hamilton Standard propeller with a governor for constant speed control. No more jiggling of the prop control lever.

[SteveF]

BL -
Getting off subject but I think many will enjoy this article about an ex air force jet pilot taking similar prop training today to finally check out in a P51
at Triple Tree Aerodrome (SC00). Cub, Stearman, BT13, AT6, and finally a P51.

Great 7K grass airfield and the picture of the Stearman and BT13 also has my Champ in the background.

TRIPLE TREE AND THE MAKING OF A WW II PILOT (IN 2015)
http://www.tripletreeaerodrome.com/makingwwiipilot.php

[Bruce Fenstermacher]

There is only one known example of a McCauley two position prop and that is installed on board member Dave Bengston's 170B.

[blueldr]

I have never seen a post WWII BT-13 or BT-15 that was still using the original two position prop system. They have all been converted and equipped with a governor and are now working as a constant speed prop.

[cessna170bdriver]

I have never seen a post WWII BT-13 or BT-15 that was still using the original two position prop system. They have all been converted and equipped with a governor and are now working as a constant speed prop.

Largest airplane I ever soloed was a BT-13 that still had a 2-position prop (late 1980's).

[edbooth]

There is only one known example of a McCauley two position prop and that is installed on board member Dave Bengston's 170B.

Back in the early eighties, some one showed up at a Kentucky Damn Resort flyin with the McCauley two position prop...I can 't for the life of me remember who it was. There was some discussion about it at the time about how heavy it as. Seemed like it was somewhere around 70 pounds.

[170C]

Ron Massicot, didn't you have one of these two position props at one time? I only recall seeing the one Dave has on his '56 170.