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Prop Options for RV7A
- Thread starter Sandrews
- Start date
The ground adj FP will provide you generally good performance. A CS prop is more $$ and a bit more complexity, but it is like riding a single speed pedal bike vs a 21 speed shifter one in hilly areas. If injected, high compression pistons or electronic ignition, you will want to use a composite prop with a 'heavy duty' hub. Like MTV-9 (3B).
Once you find the sweet spot on that ground adjustable prop, you will probably be very happy with its performance.
Resale of the whirlwind will barely put a dent in the cost of a new C/S. Prop mx is getting wildly expensive these days too.
Before considering MT, take a close up look at the MT’s at your local field and ask about owner/mechanic’s first hand experiences. You will likely notice that most of them are riddled with cracks all over the blade surfaces. MT does not back their product and says it’s “cosmetic”
Resale of the whirlwind will barely put a dent in the cost of a new C/S. Prop mx is getting wildly expensive these days too.
Before considering MT, take a close up look at the MT’s at your local field and ask about owner/mechanic’s first hand experiences. You will likely notice that most of them are riddled with cracks all over the blade surfaces. MT does not back their product and says it’s “cosmetic”
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andoman
Well Known Member
I love a CS.
In the end it depends on the mission.
Since missions change, especially over the life of the airframe (as compared to the life of the builder), a CS makes the plane more versatile over its life.
I believe a nice -7 merits a CS prop.
A light and nimble -3 or -4 has a solid argument for a FP.
In the end it depends on the mission.
Since missions change, especially over the life of the airframe (as compared to the life of the builder), a CS makes the plane more versatile over its life.
I believe a nice -7 merits a CS prop.
A light and nimble -3 or -4 has a solid argument for a FP.
A CS for a IO360 powered 7(a) will help on the back end for resale but as a few other folks have already said, it depends on your mission and your budget.
- If you want to spend the money up front, get a Hartzell and call it a day.
- If you're not looking to spend all that upfront and aren't 100% on what pitch you want, Sensenich GA is a great option. But once you find your pitch, I would think you won't be going back to it.
- If you want something in between the two above, a Performance Prop could be a good fit. The anhedral design and manufacturing process offers a lightweight propeller that "happily flexes" to offer the best of both worlds, great take-off and great cruise numbers. It's the "almost constant speed" prop.
- If you want to spend the money up front, get a Hartzell and call it a day.
- If you're not looking to spend all that upfront and aren't 100% on what pitch you want, Sensenich GA is a great option. But once you find your pitch, I would think you won't be going back to it.
- If you want something in between the two above, a Performance Prop could be a good fit. The anhedral design and manufacturing process offers a lightweight propeller that "happily flexes" to offer the best of both worlds, great take-off and great cruise numbers. It's the "almost constant speed" prop.
Assuming you want this plane to do “everything”, get the nice Hartzell aluminum two blade BA CS prop. It is the biggest bang for the buck.
My first build (8A) started life 26 years ago with a Van’s recommended FP prop. I replaced it at 300 hours with this Hartzell prop and it transformed the plane.
Carl
From a 7A builder, if you’re running a parallel valve engine and plan nice paint, interior and panel consider a prop on the heavier side. A composite prop (even CS) will likely limit your aft CG. I Love my WW composite, but the CG was not where I wanted it until I added another 30Lbs worth of (angle valve -390) engine. I had a 14Lb flywheel ring with the previous engine (parallel valve IO-360) to keep the baggage CG acceptable.
If you are going bare bones interior, light paint or polish, and simple panel disregard the above.
If you are going bare bones interior, light paint or polish, and simple panel disregard the above.
