The International Cessna 170 Association

BoisePhil wrote:No one here has stated (it's really not so obvious) how to mount an 8-bolt prop to a 6-bolt hub?

Phil

BoisePhil wrote:No one here has stated (it's really not so obvious) how to mount an 8-bolt prop to a 6-bolt hub?

Phil

Bruce Fenstermacher wrote:Having some background on Phil's question, he is interested in buying a 170 which has an 0-300-D, which of course has a 6 bolt flange. He wants to be able to mount a 8042 1A175-DM prop that the Kenmore STC covers. He wants to know what, if there is one, is the equivalent 6 bolt version and how, if it is, would this 6 bolt version be approved on 170?

BTW they did weld aluminum to steel in the WWII era. Those welders knew what they were doing.

(I've edited his post subject)

Bruce Fenstermacher wrote:So the answer to Phil's question is answered somewhere in the early pages of this thread. Phil actually brought it to my attention of line. I'm embarrassed to say I did not remember the answer. And I was the one who brought this to Phil's attention that he needed to look into it before spending his money on a plane he couldn't modify to his taste.

So the answer is the 8 bolt McCauley 8042 1A175-DM prop is covered by the Kenmore STC for 170s with a C-145-2, 2H/0-300-A, B. The equivalent 6 bolt prop is the McCauley 1A175SFC 8040 which is covered by the Associations 0-300-C, D engine installation STC. In the case of using our STC you would also have to insure the 0-300-C or D is installed per our STC as that is the reason for the STC. I don't see how a 0-300 C or D could be installed otherwise but it is an important point.

gahorn wrote:Bruce, did you mean to type the 1A-170-DM...?? an 8-bolt..?? I did not find a "1A-175-DM"

4517C wrote:Keith,
I have both a 80/46 and a 80/42 for my 53 170B with 180 gear, 8:00 tires and a 0-300A. The 80/42 gives me a cruise speed of 90/95 mph at 2450/ 2500 RPM which is where I've run it for years. The climb performance is excellent. I use the prop, not for extended climbs, but for get up and go. It allows you to break free and rotate much faster than the 76/53 which I used previously. It will also get you over the trees with more margin.
A couple words of caution however. 1. The long prop is sensitive to a tailwind while taxiing, causing the airplane to shutter. Absolutely avoid a downwind run up. 2. The 80/42 will allow the airplane to rotate when you only have marginal control. Use caution in a gusty wind. 3. The 80/42 will allow you to climb at too steep of an angle for safety. 4. You could easily overspeed the 80/42 in a slight descent.
A side benefit of the long prop is the static pulling power. Nothing beats it for moving the airplane on a soft surface. Unfortunately, only a few 8 bolts are made every year and they are pricey. Also, the prop balance and 3 inch station pitch from the factory are terrible. You wil have to have a new one tweeked. Jake