Maximum PITCH on DA-50 & DA-100

[avionics]

Hi Guys;

Has any one tried to see what is the maximum pitch Da-50 and Da-100 can handle without loosing Rev. I want to test it on my engines but if you have experienced it i appreciate if you share it with me.

Cheers

Reza

[Vic3D]

For a 2-blade I would say a 10 pitch on the 50, and a 12 on the 100. 23x10 and 27x12 (max) If you don't wanna lose revs then 26x12 is probably the better option.

[GremlinX]

I borrowed a 23x10 and it was a dog... I put my 23x8 back on it, much better... Maybe a 22x10?

[TheTank]

All depends on how much you want to drop the diameter of the prop. I used to have the load formula for props, but cant remember it off the top of my head. I had used it when trying to find the optimal prop for my 2.6m Extra/ZDZ 80 combo.

[Cobra1]

I have always used Dia^3 x pitch as an engine load formula. Lets compare 3 props a 22x8, 20x10 and a 23x8
Example - 22x22x22x8= 85,184 20x20x20x10= 80,000 These two props have a similar engine load. A 23x23x23x8= 97,336 would be a much greater load than either. Hope this helps.

[avionics]

	Quote: Originally Posted by Cobra1
	I have always used Dia^3 x pitch as an engine load formula. Lets compare 3 props a 22x8, 20x10 and a 23x8 Example - 22x22x22x8= 85,184 20x20x20x10= 80,000 These two props have a similar engine load. A 23x23x23x8= 97,336 would be a much greater load than either. Hope this helps.

Thanks that sounds interesting can you tell me where do you get Dia^3 from and what is the significance of this result. I can see the ones that match are in the rage of 80,000 but what is the significance of the 80,000. can i read more about this please.

THNX

[Jaybird]

I always use the formula of see what everyone else uses

[Cobra1]

The 80000 number has no significance at all. The point is that when you do the math on any two props and the result is close then the props will act like a similar load to the engine. This formula came from Dub Jetts' web site and it is just used as a ballpark result so you don't load your engine too much, or too little for that matter. I use it when I am comparing a prop for speed to a prop for pull so the engine doesn't get lugged down.

[MattyMatt]

Generally I use the standard method of: 2X diameter and add the pitch.

So a 22X8 would be a load of 52, and a 22X10=54

a 20X12= 52


a 26X12= 64 or a 27X10= 64... which is about how a 100cc engine would see the load.

or for speed baby: 22X22= 66!