quiet props on big engines

[dick hanson]

Recently I hav been running new ZM props on 160/80/50 cc engines
these props have a much thicker hub and a bit different shape . They also are numbered higher than sizes we typically ran
The hubs transfer to a extremely steep pitchclose to the propeller.
On the 160 J ZDZ, using this prop in the 30x14 size, the engine never rips the prop yet performs extremely well -It will hold in a hover easily at middthrottle and pull easily vertically from the stopped position (radiocraft 42%Extra)
In full .wide open level run - no rip and the big JMB cans are quiet.
This type combo solves the noise issue for me. When I tried a 32x10 prop -any application of power --even small - resulted in big prop noise .
so -- on the big engines -we need props with more pitch which means we need lots of engine grunt to turn em The 200 size engines require much the same thing .
On full sized aerobatic craft --the pitch is relatively higher than what we use on our models -

[torquen]

Dick, we have been running the new 3w 32x14 carbon prop on our 150's 157's 200's and 212's. They are performing very well. You might want to try one of those as well. Great pull and quiet performance.
Garrett Morrison

[JPrc]

Dick, we have been running the 3W 32x14 CF props on our 157's with the same results. Very quiet with excellent downline braking and flight speeds. The only issue I have is I would like a prop that is a little faster in windy conditions where the plane penetrates more. As far as 3D goes, you would think you were running a 32x10 with how fast the motor spools up and how hard it pulls out of a hover. I would like to try one of these but it gets so damn expensive. Wanna trade for a week?

[JPrc]

Damn, didn't realize you already posted.

[Flyinrazrback]

Jonas, so you are saying my 3w 150SS on full pipes with the P-tip does not qualify as quiet?

[dick hanson]

I will have to look into the new 3W props . this plane is about as large as practical and at almost 40 lbs -at this altitude ,I would not want to pull the engine down and loose power.
I see almost same product improvements coming from the Czechs and the Germans - apparantly - not simply coincidence

[alec taylor]

whats wrong with 4 blade props alex