McCauley 1B90 74/47

[Jim Herpst]

What kind of performance are tribe members that have this prop getting with a Continental A65 ?

[mike lutz]

In my past experience over 47 years, and around 2500 hours with my prewar 1940 Taylorcraft, my vote is for the McCauley 74-45. I say this because over the years I have played around with many different props, wood and metal alike. Long ones, short ones, modified experimental ones. My mission for my use is a good general use prop that gives decent take off and climb, and a fair cruise. At 2200 RPM my cruise is 100 Mph. My airplane is perfectly rigged and 750 empty. My field elevation is 800 ft. This is my set up and I am very happy with it. I realize this is not what your asking in your post, but I thought maybe this could give you some extra info.

[Jim Herpst]

Mike , What part of the country are you in ?

[mike lutz]

Jim, I am located 5 mi south east of Findlay, Ohio, which is the north west Ohio area. 45 mile south of Toledo, Ohio. Farm strip.

[Jim Herpst]

Reason for my asking is the BC12D(and same prop) I am discussing is the one Dad owned and I learned to fly in when 10 through age 14. We lived in Pittsburgh and flew from a farm strip in Mars PA ..Lake Hill airport .I can recall when we took off frim Zelinople Airport after filling both wing tanks full early on a summer morning in late July heading for OSHKOSH Dad (who never weighed much and with me at age 12 did not weigh much) and not much luggage in the sling experienced climb performance that had him saying good grief while pointing at the rate of climb gauge..fast forward 31 years. Now back and as a project in South Carolina. Density altitude can be a factor in the summer here. I do recall she was an honest 100 mph cruise with that same prop that is still with the plane. I am lightening the plane as much as possible (like the ROC and venturi and needle ball gage being tossed out and hopefully a lighter finish ) but let's get real again. ! That prop may have to be repitched!!

[astjp2]

It was a dog for me, I would go with a 74/43 so you can get up and off the grass strip. Long and flat like a borer prop...

[Jim Herpst]

It was a dog for me, I would go with a 74/43 so you can get up and off the grass strip. Long and flat like a borer prop...

That may well be in the cards

[Jim Herpst]

It was a dog for me, I would go with a 74/43 so you can get up and off the grass strip. Long and flat like a borer prop...

Also Tim I have seen elsewhere on the forum where you posted this prop in its 74/43 format works great on an 0200? Really? I would think it too long to turn up a 0200.

Did I read that correctly?

Thanks
Jim

[astjp2]

Also Tim I have seen elsewhere on the forum where you posted this prop in its 74/43 format works great on an 0200? Really? I would think it too long to turn up a 0200.

Did I read that correctly?

Thanks
Jim

Standard F-19 prop is a 7443, so yeah that's correct. Cessna 150 sea plane has a 7538 and a 7535 props also which are an inch longer. Dont misinterpret a long prop as one that wont turn up, it just needs the correct pitch to get the rpm in to the correct range so the engine can make full power. The7446 just would not turn up to RPM on the o-200 so it was a dog. I can keep up with a "68" O-200 standard prop and out climb him and get off the ground much sooner than they believe is possible with my long prop. if you want to read more about it, compare it to a borer prop, those are like 84" on a Lyc 15hp O-320. Tim

[Jim Herpst]

Tin, I also read here that Dorothy Ferris ordered that prop and it was used on a seaplane. I believe with DAR approval it could be used on a land plane as well with the O200 Tim offers in an STC. Not speaking for Tim on the prop combination mind you.

IF repitched for use on the A65 I wonder what is legal. It has been 74/47 for as long as I have known the plane put on around 1951 according to the log entry...Climb is important in the South...even just that hand full of times that things can make a difference!!.

[Woody]

Jim,
I have a 7443 on a clip wing Tcraft with 0200. It will turn 2600 in cruise.
As far as what is legal on a BC12 the TCDS spells out lengths and permissable rpms.
Tom

[Kerbs]

I had a 7445 on the A65 and it flew like that for a lot of years with my dad before I had the plane. I flew it that way for about two years and then rep itched to a 7443. Boys howdy did it make a difference in climb with the A65 and I really didn't give up more than a mph or two in the air. Still seemed to cruise at about 95 at 2,150.

[Jim Herpst]

I had a 7445 on the A65 and it flew like that for a lot of years with my dad before I had the plane. I flew it that way for about two years and then rep itched to a 7443. Boys howdy did it make a difference in climb with the A65 and I really didn't give up more than a mph or two in the air. Still seemed to cruise at about 95 at 2,150.

Thank you Kerbs. That is good to know and most likely the way I will go.