climb prop question

How to keep the Cessna 170 flying and airworthy.

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BoisePhil
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Re: climb prop question (8042 1A175-DM propeller)

Post by BoisePhil »

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

Phil
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GAHorn
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Re: climb prop question

Post by GAHorn »

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
Hello, Phil!

I'll go for it. I'll "presume" you are asking a tongue-in-cheek question....

If mounting an 8 bolt prop to a 6-bolt hub... one of the most secure methods is to hire an aircraft-certified WELDER, who knows the secret of welding aluminum to steel, to do the job. No bolts needed after that. Be sure to use a wet-rag wrapped around the crankshaft flange so as not to melt the prop oil-seal or tamper with the crankshaft temper. :twisted:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
hilltop170
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Re: climb prop question

Post by hilltop170 »

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
To clarify George's response, you don't mix 6-bolt and 8-bolt props and flanges. Get the correct prop for the flange.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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Bruce Fenstermacher
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Re: climb prop question

Post by Bruce Fenstermacher »

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)
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Joe Moilanen
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Re: climb prop question

Post by Joe Moilanen »

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)
There is and it is approved and I have one on my 170B with an 0-300-D
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Bruce Fenstermacher
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Re: climb prop question

Post by Bruce Fenstermacher »

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 :oops: 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 for a seaplane only. 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 and get approval for install on a land plane

*underlined texted added
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KG
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Re: climb prop question

Post by KG »

edited... question answered above...
Last edited by KG on Sun Sep 10, 2017 9:52 am, edited 1 time in total.
53 170B
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GAHorn
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Re: climb prop question

Post by GAHorn »

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

http://rgl.faa.gov/Regulatory_and_Guida ... /P-857.pdf
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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wabuchanan
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Re: climb prop question

Post by wabuchanan »

George,

Possibly I misinterpreted your question, but top of page 5 lists the 1A175DM prop for O-300 engines of 145hp and 2700rpm. It is the Seaplane prop and the prop in the Kenmore STC for wheeled 170's.

And what I am using on my aircraft.

If I misunderstood your question to Bruce, my apologies.

Bill
1950 170A N5776C SN:19730
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Bruce Fenstermacher
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Re: climb prop question

Post by Bruce Fenstermacher »

gahorn wrote:Bruce, did you mean to type the 1A-170-DM...?? an 8-bolt..?? I did not find a "1A-175-DM"
No George, I meant 1A175/DM. This prop is listed on the second page, 6th down, in the guide you attached.

I get the model name from a source other than Kenmore's STC assuming the info I was reading was correct about what was listed in the Kenmore STC.

I also added a few more words to my original post to include our STC currently only allows the 1A175SFC on a seaplane. One would have to get further approval to install it on a land plane. I'd meant to go add those words but our forum went down just as I was doing it and I never got back to it.
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GAHorn
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Re: climb prop question

Post by GAHorn »

Thanks. Guess I just missed that. :?
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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170dreams
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Re: climb prop question

Post by 170dreams »

Recently I started to look into the McCauley 8040 prop. It would be for an O300D (6-bolt flange)
I searched the posts on climb props etc and ended up on this one.
Bruce has mentioned that the STC SA7441SW, owned by the association, covers that installation (on a seaplane).

However, when checking the actual revision of that STC I don’t find the 1A175/SFC8040 on it.

What am I missing?
Has that prop been on an earlier revision of that STC ?

Wolf
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bgiesbrecht
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Re: climb prop question

Post by bgiesbrecht »

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
Curious about the 80/46. I've only heard of the 80/42 and 43. What type of difference do you see with the 46 profile vs. 42? I have a 7651 (just recently repitched to it from a 7653) and enjoying the noticeable increase in climb rate, but an 80" would be sweet. I am cautious to give up too much cruise speed, however. Right now I'll true at around 100 ktas.
Former owner of:
1953 170B
N1977C
s/n 26122
Lhorn
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Re: climb prop question

Post by Lhorn »

Hello all, I'm new to the site, and looking for a place to land a prop question, and found this thread. Seems like a good fit. I'm in the midst of a fravel TW conversion on my '56 model 172. I would like to run the 8042 prop, but need to find approval. Plane has the original 6 bolt flange O300, and it looks like all the stc's have been for the 170, and not the 172 (probably for clearance issues). Planning to run bush wheels, and operate in and out of a private strip at 9500' agl, so need all the jump I can get. Anyone wade in these waters before?
Lhorn
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Re: climb prop question

Post by Lhorn »

Let me rephrase my question without so much fluff: Anyone out there with a field approval to run the 8042 prop on a 1956 172TW, O-300-A? Any help greatly appreciated. Don't want to invent the wheel if I don't have to.
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