Prop Pull Testing Catto Props 0-375

[Mauleguy]

I am pretty sure that 37" or whatever you have pitched your prop to in inches is a theoretical number and that through the air movement is going to vary on each make of airplane based on it's own drag profile.

I have watched them re-pitch my prop several times and it is not a pretty thing, it's a guy that knows what he is doing with a big cheater bar, this is the best way to describe it. I think there is some room for error, how much I am not sure!

Greg

 

[palhal]

pa18guru----Where do you get that I don't know that pitch refers to forward travel! I don't appreciate your insults on this forum.

If you would read in the above post I ran 8 1/2 to 1 compression with the 90" for 108 hours and the pistons looked like new. I went to the domed pistons 9.6 to 1 and got my static rpm now at 2450.

90X37 prop 8.5-1= 2350 RPM.
90X37 prop 9.6-1= 2450 RPM.


I don't care what pitch anyone is running. If you get 2450 static you should be happy.

Greg--I think you are right that the air movement will vary on make of aircraft due to drag profile. I believe the slats in front of my wing is not helping my cruise speed.

Harold K.

 

[gander]

Pal, What kind of MP were you seeing with 8.5 and 9.6???
This is all good data, seems maulguys numbers look the best for MP rpm fuel burn cruise. Maybe the 375 is just such a torque monster it can swing a 90-37. I would like to see the same prop on a 375 and 360 10:1.

 

[palhal]

gander----I don't have a manifold pressure guage to give you the numbers. I did everything possible to keep this aircraft as light as possible.

Bart said that the 0- 375 made better torque than expected. The 9.6-1 pistons helped the hp mainly we guess by the flame pattern rather than the compression rise. There is a dome on top of the piston and the piston pins must be offset in the pistons because the piston has to go in the cylinder with the arrow pointing forward.

Have you finished the new pod yet?

Take care,
Harold K.

 

[Dave Calkins]

Boys, miscommunication is no reason to get snippy or get offended.

let's communicate so we can get on the same page.

I did not realize that Mauleguy was talking about the 90/32 on the Maule. I thought that was on the Cub.

I was not flying the day the hotrod motor got sick. I think it was a problem on that day only, as it never acted funny to me, then I got this call to fly out to where it was.

As far as CaptAmerica's rig, I think that our thrust numbers will go up here in a couple of weeks. 8)

 

[dougsappllc]

Prop pull test

The long awaited Rhinometric Calibrometer has finally arrived, now we can pull test the 4 blade Warp drive against the Borer, same day same temp same aircraft. Anyone close to Omak WA who wants to take advantage of it while it's here, please give me a call, 509-826-4610. It's borrowed, so it will only be here for about 3 weeks. Plan to give it a go next Sat and Sunday. Will post what we discover.

 

[gander]

Pal, I have gotten side tracked on my helio project when the wings are finished i will be making some new style pods and few other new additions.

 

[av8ron]

My, my, my where have I been during all this discusion?

Although Ol' 18guru has ruffled a few feathers, he raises some good points. But pa18guru, you might want to lighten up on these guys. I've figured out from years on this site, they don't like it when you start questioning their ability

Josh called me the day they were testing and I couldn't make it. It will be interesting to try that Catto on my O-360. I don't have 10:1 though. It would be interesting to see the diff between an O-360 w/10:1 vs O-375

Ron.

 

[brooks18]

Dave, You sound like my teenage kids every time i find a dent in the car." It didnt happen when i was driving"

 

[JimC]

.....I found that on this big prop 1 degree of pitch change = 25 rpm

Greg, did you mean 1 degree, or 1 inch?

Re other posts about pitch measurements, most manufacturers measure pitch at about 70% to 70.7% (square root of 2 over 2) of semispan -- but not all do that, so it's not appropriate to compare pitch measurements directly between different manufacturers, and different choices for semispan variations in angle of attack, airfoil distribution, and chord make the comparison even more tedious. Personally, I like Hartzell's propmaps as an easy way to compare prop changes, and wish more prop manufacturer's would emulate their techniques (not their props, just their calculation and presentation methods).
JimC

 

[tcraft128]

Any new info? Did you test the warp drive?

 

[Fencer]

What happens when a composite prop hits something, do they bend up like a borer or do they just shatter?

 

[Bugs66]

I would like to see how the Catto compares to the McCauley 84/43 I have on my O-360. Maybe I can participate in a pull test in WA state or nearby. I think the 1P235 in 84/43 is a nice sweet spot for the O-360 on a Cub, but curious what else is out there.