[itizme]

I was out at the Stoney Creek IMAC event yesterday and one thing that I thought I would be able to figure out there was the prop selection for my DA 150, was I ever wrong on that thought.

I saw a complete mix of prop sizes and unfortunately I was unable to talk to the various pilots about their choices and rpm's so maybe I can accomplish that here?

My DA150 is mounted in my 42% 260, I currently have a Mejzlik 3bl 29-12N installed that turns 6300 on the ground. Set up is with headers KS cans, running ethanol free Shell 91with Redline @ 40:1. Engine fully broken in.

I do not have enough experience with this setup to know good from best however I have the following props on the wall:

Tested:
Mejzlik 3bl 29-12N 6300 RPM on the ground and sounds like it is ripping in the air, maybe takes a little bit of time to achieve this ripping rpm but any straight and level pass is enough time for sure ( with the cans it is still reasonable for a sound score)

All below untested:
Air Models 3bl 29-12 ( very similar to the Mej N)
Mejzlik 2bl 32-10
Mejzlik 2bl 30-13 EVOL
Mejzlik 2bl 30-12

If you have used the DA with any of these sizes and reasonably the same exhaust setup please let me know what I can expect both in performance and rpm.

Also the 28.5-12 3bl I would like to know including that I would like to know if it will lower that 6300 any.

All flying from elevation of no more than 700 ASL

[wingburner]

The Mej. 32/12 and 30/13 are too much prop.

Mej. 30/12 works great and if memory serves me correctly, is quiet enough and great all around prop. Quick spool up and likely around 58-6000 rpm.
.
Mej. 28.5/12/3, reasonable spool up, works very well, a bit of performance loss over the 30/12, but is very quiet! Likely around 55-5700 rpm.

Mej. 32/10 will also work well and is likely 56-5800 rpm.

[itizme]

Jack, do you know if the 28. 5/12/3 is more prop than the 29/12n/3 that I am spinning 6300?

[wingburner]

Steve, yes it is more load. The blades on the 28.5" are much wider.

It's an excellent prop in my mind. The 29" is a better performance prop but noisier as per your findings.

[itizme]

Originally Posted by wingburner

Steve, yes it is more load. The blades on the 28.5" are much wider.

It's an excellent prop in my mind. The 29" is a better performance prop but noisier as per your findings.

Thank you

[Trumpetman]

I'm using the Mej. 28.5/12/3 on a DLE 222 with my 42% Dalton Extra. I'm pretty sure I can rip the prop in a full throttle level pass but for IMAC purposes I only go to full throttle on a 45 degree or vertical upline so it will not be an issue. If you like how the plane flies (good upline pull etc.) IMHO I would stick with what you are using and just pull back the throttle on the level passes.

If you are looking for 3D performance then ignore everything I have just said and listen to guys like Wingburner!

[itizme]

Hi Gordon
Good advice, I better get the thing back in the air and see if there is anything I don't like about the selection installed right now (beyond the noise/rip). Maybe I'm looking for answers without knowing of an issue.

[super08]

My favourite two props on the 150 were the Mejzlik two blade 30x12 and the 32x10. Mine was on DA mufflers. I was 6K on the 30x12 and it was very quiet. The 32x10 was around 5600-5700 and was somewhat louder but not offensive. The 32" prop pulled much better and had better down line breaking. Overall I preferred flying with the Mejzlik 30x12. All depends on your plane and flying style.

[wingburner]

Bingo...thx Doug, my finding were exactly the same.

Used the 32/10 mostly but for IMAC I did use the 30/12.

[wingburner]

Originally Posted by Trumpetman

I'm using the Mej. 28.5/12/3 on a DLE 222 with my 42% Dalton Extra. I'm pretty sure I can rip the prop in a full throttle level pass but for IMAC purposes I only go to full throttle on a 45 degree or vertical upline so it will not be an issue. If you like how the plane flies (good upline pull etc.) IMHO I would stick with what you are using and just pull back the throttle on the level passes.

If you are looking for 3D performance then ignore everything I have just said and listen to guys like Wingburner!

LOL...well said Gordon...your plane looks fantastic by the way!!