fisher1648

I've been reading the seemingly endless posts on prop recommendations for Brison 3.2 engines. My question is this: Since I fly at 4800 ft msl I was wondering if the prop/engine performance will be similar. I realize I'll have a power (RPM) decrease due to less air density but will Prop X pull better than Prop Y at all elevations ? or will my results be dependent on my elevation with respect to the "best" prop ?

I'll be replacing an A&M 3.2 with a new Brison in my Giant Stinger. It's been a few years since I flew it and have forgotton which prop I liked best out of a handful of 22" and 20" Zinger wood props.

Anybody got any RPM / Prop numbers taken at 4800 ft msl ?

Icebird

In my experience, I've found that the rpm is similar, but the thrust is considerably lower. You won't get great performance from ANY of the Zinger props, what I find works best is a wide bladed prop, something along the lines of an MSC or Biela works pretty well at higher altitudes. You need to get a better "hold" on the air to push it when it gets thinner.

HTH
Jim

ptgarcia

My Feedback: (36)

You won't get great performance from any Zinger prop at any altitude. They're just not very good props when compared to others available. If you want to stick with a wood prop get yourself a 22x8 Menz S (S for standard) or MSC. If you don't mind spending $50 roughly pick up a 22x8 Biela or Mezjlik carbon fiber prop. My Brison 3.2 runs awesome with a 22x8 Biela. It pulls my 28% Laser 200 around with authority.

fisher1648

Who is a good mail-order source for the Menz and MSC props ?

ptgarcia

My Feedback: (36)

[link=http://www.desertaircraft.com]Desert Aircraft[/link] sells Menz, Mezjlik, Air Models and Bolly. [link=http://www.aircraftinternational.com]Aircraft International[/link] sells 3W, MSC, Biela, Bolly, Fuchs and Menz among others.

fisher1648

I'll order a Menz 22X8S.

Do you think a 22X10 would help compensate for my altitude ? Or is that going to be too much pitch for the 3.2 ?

Experimentation is gonna be pricey !

ptgarcia

My Feedback: (36)

Here at roughly 800' ASL a 22x10 on a Brison 3.2 is too much. For more thrust you want to go larger diameter any way. If the 22x8 turns at 75oo rpm or so try a 23x8. Either way I would stick with an 8-pitch prop. Good luck!

fisher1648

OK - thanks for the info....I'll post the results in a couple weeks when I get the engine fired up.

Wings-RCU

My Feedback: (2)

As a full scale pilot I can tell you that you will turn higher RPM's at a higher altitude. You will need to run a leaner mixture and a higher pitched prop. Forget the 23 x 8 & go with a 21 x 10 Mej or 22 x 10 BME or 3W Prop (I don't think you can get Menz any more & the 3w & BME are both a great clones of the old Menz props). If it were me at 4800 MSL I woud run a Mejzlik 21 x 10 if I could find one. Check Don's Hobby out of Salina Kansas. He has all of these props. I'm not sure about the sizes.