Flottrop Prop Question

[Fred W]

Hello everyone!! i am a new member to the tribe although i hve been lurking
awhile. My BC12D has a Flottrop wooden prop 72X48. it seems poorly
made as the metal leading edge sticks up from the wood of the propeller.
My cruise is lower than i would like at around 87mph gps verified 2 directions at 2150rpm.
I am considering going to a Sensenich metal prop 74X48, do any of you have
experience with either of these props?
what kind of improvement should i expect on 65 hp?
thanks, Fred

[dedrekon]

Re: Flottrop Prop Question

Fred,
Don't get too anxious to get rid of that Flottorp Prop! They're generally of excellent quality and can be rebuilt if badly worn.

87mph on a wooden prop and 65hp doesn't sound too bad to me. I have a McCauley 7445 with the 65 and run just under a 100mph at 2150. You'll generally always pick up some speed with a metal prop.


v

[jgerard]

Re: Flottrop Prop Question

74-48 could be just a bit too much pitch. You may not be able to pull the minimum static required for the A65 and you will burn up cylinders faster at 2150 than if you ran a 74-45 2300 all day long. Remember that these little engines last longer when you don't try to overload them with a fat prop at low rpm. Rule of thumb says that the engine should be able to turn max rpm in level flight with what ever length/pitch prop you decide to run. If it won't then you need to flatten it, or worse shorten it. Experience has taught me that with a cruise prop it is not recommended to maintain extended climbs at VX or even VY, Instead you should use a cruise climb or step climb to keep from overheating the engine when trying to put a lot of airspace between you and the surface. The Tcraft responds well to aerodynamic cleanup, and weight reduction in regards to increasing speed.

[M Towsley]

Re: Flottrop Prop Question

Fred,

In my limited experience you are, like my L-2 was, way overpropped. I had a McCauley 74-45 on my BC-12D and it was a nice all-around prop. The Flottorp I had on my L-2 was similiarly pitched as yours and it was a dog. I could barely clear the trees with two people on-board. I'm not sure how my ferry pilot got it over the mountains! What Jason says is true and I think my cylinders have suffered for it. My crankcase pressure is way up and I am always oozing from the front shaft seal, all with less thank 200 hours on the engine. The Flottorp prop I had, which will be a wall hanger, had been refinished sometime in the past. Part of the armor coat had been stripped away and the wood was worked down enough to see the reddish colored glue on the laminations. I am not overly thrilled with the Flottorp either, but I think it has gone through hell during it's life. I would never put this prop back on my T-Craft as it is probably for an 85HP, or something close to. The standard prop is a 74-45, for a McCauley metal, and I really think you would be happy with that one.

[Frank DeBartolo]

Re: Flottrop Prop Question

How does a McCauley 7443 work on a BC12-D with an A-65 Continental engine? Is that more of a climb prop? Does it work OK as far as engine wear and performance.

Thanks,

Frank

[Ragwing nut]

Re: Flottrop Prop Question

7443 are typically found on Champs when you can find one. It would be a stock prop. I typically run a 71-48 metal or 74-42 wood. Metal prop is worth around 10 mph. I can't explain the disparity between the 2, other than the meatl has more flywheel effect and has a slightly narrower chord, ie. less load inboard therefore more pitch to compensate. props are a black art.

Mike

[M Towsley]

Re: Flottrop Prop Question

I agree with Mike, it is a black art. Search the archives, Fred, for props and you will find past discussions on this topic that may be helpful.

[Karl Rigdon]

Re: Flottrop Prop Question

When I removed the ck72/44 for a 74/45 Mc caulley my IA said I would use 100ft less take off roll and gain 10 mph. He was right. I fly out of my at home rumway (1000 ft) at gross without any problem. 800 ft msl though.

[Fred W]

Re: Flottrop Prop Question

Hi everybody and thanks for your responses. I received an e-mail from
Ed Zercher at Sensenich, he stated that Sensenich measures pitch a bit
differently than McCauley does. Generally Sensenich's pitch runs 2 inches
higher that McCauley. This would make the Sensenich recommended 74X48
about the same as a McCauley 74X46. Why do I want a Sensinch? Beacuse
they are a few hundred dollars cheaper! Ed recommended that I maybe
go with a 74X46 which is the climb prop that they recommend. I agree with Ed's recommendation because the climb prop 74X46 (Sensenich) will
absolutely give me better climb, if i want to go fast, all i need to do is
cruise at about 100 rpm greater than the standard prop and i will get the
same cruise as if i had bought the cruise prop! Ain't that great! It will
also keep from lugging the engine with lower cylinder pressures.
If I'm not happy, I can always have the prop re-pitched one way or the other
anyhow. So what do you guys think about that?
Happy Holidays, Fred Westerling

[Ragwing nut]

Re: Flottrop Prop Question

Hi everybody and thanks for your responses. I received an e-mail from
Ed Zercher at Sensenich, he stated that Sensenich measures pitch a bit
differently than McCauley does. Generally Sensenich's pitch runs 2 inches
higher that McCauley. This would make the Sensenich recommended 74X48
about the same as a McCauley 74X46. Why do I want a Sensinch? Beacuse
they are a few hundred dollars cheaper! Ed recommended that I maybe
go with a 74X46 which is the climb prop that they recommend. I agree with Ed's recommendation because the climb prop 74X46 (Sensenich) will
absolutely give me better climb, if i want to go fast, all i need to do is
cruise at about 100 rpm greater than the standard prop and i will get the
same cruise as if i had bought the cruise prop! Ain't that great! It will
also keep from lugging the engine with lower cylinder pressures.
If I'm not happy, I can always have the prop re-pitched one way or the other
anyhow. So what do you guys think about that?
Happy Holidays, Fred Westerling

I assume we are talking metal Sensenich? Either wood or metal, I would not recommend that much length with that much pitch. The 65 won't pull it. Length has more effect on rpm than pitch does. If you want that amount of pitch, I would get a 72-46 prop instead.

Mike

[Fred W]

Re: Flottrop Prop Question

Sorry Mike, in my last post i neglected to mention these were metal props
I was talking about.
Merry Christmas everyone.
fred westerling