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Better prop

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Scott
Posts: 18
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I have a 108-1 with the 150 Franklin and the stock sensenich propeller.  The prop is not suited for take off/climb at 3500'.  Does anybody have a recommendation for a more efficient wood prop?  Univair sells McCauly & Sensenich.  SInce the type certificate specifies wood prop, metal is out.  Is a wood composite prop considered wood?  I'm willing to sacrifice a little speed for better climb.  I'm hoping that more modern/efficient will solve the problem.  The Sensenich looks nice, but aerodynamically it looks terrible.  Thanks.

 
Posted : 20/07/2022 11:59 pm
resto108
Posts: 278
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Pages 9 and 10 of the Type Certificate Data Sheet specifically allows metal props from Sensenich and McCauley.

 
Posted : 21/07/2022 10:14 am
Scott
Posts: 18
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I guess I was a bit unclear about metal props.  They placard for restricted rpm between 2100 and 2300 rpm.  The vast majority of serious crankshaft related problems that I'm aware of have metal rather than wood props.  Evidently metal props set up a resonance that aggravates the cracking problems.  They say "any wood propeller" that meets the engine operating parameters.  They are specific about which metal props.  They don't allow any metal prop.  Hence for me I don't like a metal prop on this engine.  Does anybody have any experience with other wood props than the Sensenich?  If I put on a McCaulley, does it provide better performance?  Will dropping the pitch by 1 have much effect?  Thank you

 
Posted : 21/07/2022 2:17 pm
Will Ware (Webmaster ISC)
(@stinsono)
Posts: 363
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Yeah the thing that’s missing in the tape certificate when they say “any wooden prop” is they don’t say certified. We are working with a company in the UK called Hercules props that makes a wonderful propeller but it’s not certified in the US so it doesn’t meet the type Certificate requirements based on who you talk to at the Faa.

 

Yeah the thing that’s missing in the tape certificate when they say “any wooden prop“ is they don’t say certified. We are working with a company in the UK called Hercules props that makes a wonderful propeller but it’s not certified in the US so it doesn’t meet the type certificate requirements based on who you talk to at the FAA.

 

 There are plenty of experimental wooden props that I’m sure it would work perfectly on this aircraft but then again they’re not certified so other than the prop you mentioned in your post I’m not sure there’s another alternative at the moment unless you get a field approval or some other means of compliance . 

 
Posted : 22/07/2022 10:21 pm
Carsten H. reacted
Wade Modrow Modrow
(@wademodrowoutlook-com)
Posts: 20
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Does anyone know of a composite prop for these?  Something like an MT propeller but with the eight bolt pattern 

 
Posted : 22/07/2022 11:24 pm
Will Ware (Webmaster ISC)
(@stinsono)
Posts: 363
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Posted by: @wademodrowoutlook-com

Does anyone know of a composite prop for these?  Something like an MT propeller but with the eight bolt pattern 

Sure, MT and others can make a prop that will fit, but what is your certification path? For me Im strongly considering "Experimental Exhibition" which frees me to do what I want with very little restriction. I have spoken to a few DARs that work with the STOL crew and its a worth consideration for me, but that's not for everyone. 

The problem with a prop is its a PRODUCT which means it should have its own TCDS. This is different than and APPLIANCE like substituting a alternator, or other thing that could be done via a field approval. 

I would LUV to do a Catto or MT prop. MT has done a lot of front end work for the Stinson but we have not gotten to a test yet as I understand. 

 
Posted : 24/07/2022 2:01 pm
James
(@paxflyergmail-com)
Posts: 29
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I again spoke w MT prop at EAA- July 22'. When I mentioned my TCDS said any FAA approved wood prop is OK, he said YES, his prop would be fine. Just show the FAA rep my TCDS and prop paperwork. Done, stamped approved for install. He said to use the 170-189 CM, hub type 3, SEA No 2, with a USA price of $3600.  I still need to see if this hub pattern will match the F165 8-bolt hub pattern. I believe the same prop includes spinner, back plate and hardware, but I could be off on this.

 

I meant to go by the Stinson table to ask if they had heard of these same comments but forgot when I engaged Eddie Stuart. He's such a fun guy to talk with !!

 
Posted : 31/07/2022 2:52 pm
Wade Modrow Modrow
(@wademodrowoutlook-com)
Posts: 20
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That sounds great, thanks! Catto has a similar deal on an experimental ...which has stood the test of time.  I wouldn't be worried about it too much either way.  I'd like to get away from metal eventually, easier on the engine.

 
Posted : 31/07/2022 8:52 pm
James
(@paxflyergmail-com)
Posts: 29
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@wademodrowoutlook-com 

Does Catto sell a certified prop? You have the model number that would fit our Franks?

This post was modified 4 months ago by James
 
Posted : 01/08/2022 1:29 pm
Will Ware (Webmaster ISC)
(@stinsono)
Posts: 363
Reputable Member Admin
 
Posted by: @paxflyergmail-com

I again spoke w MT prop at EAA- July 22'. When I mentioned my TCDS said any FAA approved wood prop is OK, he said YES, his prop would be fine. Just show the FAA rep my TCDS and prop paperwork. Done, stamped approved for install.

If you get his prop installed, can you please involve HIM in the process, bc I think the whole community would benefit from having MT provide data to support the approval. 

 
Posted : 02/08/2022 2:13 am
James
(@paxflyergmail-com)
Posts: 29
Eminent Member
 

Not sure I'm the best one to move forward. I just spent $1200 to have my macauley OH to 0 SMOH.  Might be a while.

 
Posted : 02/08/2022 2:29 am
Scott
Posts: 18
Eminent Member
Topic starter
 

After more research, it seems like sensenich is the only certified wood prop that I can find.  Called them up, and the wood airplane prop guy there knew what my problem is and suggested going to a 51 pitch.  Said 52 is too close to 53 and by the time all of the tolerances figure in, you may wind up with virtually the same prop.  He also said 51 will climb much better and you don't lose any top speed, but the engine will be running 30-40 rpm faster.  Sooo, I pulled the trigger on the 51 prop.  We'll see.  Has a 6-8 week lead time.  Yeesh.

 
Posted : 07/08/2022 7:59 pm
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