C/S Prop questions- RV-7

[JPalese]

You are building an RV-7 that will have an O or IO-360 engine. and a constant speed prop.

Which prop would you pick and why?

MT - 2 or 3 bladed

WhirlWind - 2 or 3 bladed

Hartzell - 2 or 3 bladed

What about the prop governor - which one and why?

Cost over the lifespan of the prop and governor are as, or more, important than initial cost.

[Brantel]

For me my main concern when picking a CS prop for a 7 would be the fact that if you build per the plans with a typical glass panel, one battery and minimal interior, it will come out with an empty CG that does not allow for the full baggage allowance.

If I put a CS prop on my airplane it will be an all metal one due to this issue with the CG.

Brian Carroll has a WW and his plane is FAST!

[hydroguy2]

I see you are where I was 3 yrs ago. What's best...is a subjective choice. What's your budget & mission probably needs defined first and then stick with it.

I chose to build a fast XC fun machine VFR only. But what I failed to do was get real with my budget. I wanted a IO-390 then looked at IO-375... But my wallet was on life support and neither was possible. Project was on hold

I ended up with a overhauled O-360 A1A parallel valve, but had the builder use 9:1 pistons and superior cold sump. Then I bought a used AFP injection and Pmags. I don't know rated HP but estimate it at 190+. Cost in 2009 ~$20600, ready to run. Turns out this was the right choice for me. Saved $ and still got a powerhouse.

For the prop: I rode in C/S propped RV-4, before i ordered my tail kit....so I always knew I would go Constant Speed. Then the day I saw the Whirlwind 200RV, I quit looking for anything else. My lucky day because the WW is FANTASTIC! It is smooth and lighter than the Hartzell, I would guess speed is equal.

Don't recall the model of my governor but it was the one recommended for this prop

[jdeas]

Originally Posted by hydroguy2

I see you are where I was 3 yrs ago. What's best...is a subjective choice. What's your budget & mission probably needs defined first and then stick with it.

I ended up with a 3 blade MT IO-360. But I plan to fly high where the three blades "may" give me more speed and lower vibration. Downside is most likely a bit slower below 10k and the cost.

[RV7ator]

You aren't going to get any cheaper life cycle costs than a Hartzell 2-blade, two electronic ignitions, and a carbed 360 (since you asked in another thread).

Brian's point about c.g. is quite right. You want every ounce in a 7 pushed forward to give you the most useful load in the baggage area.

Composite props have their focused performance emphasis, but they cost more than the big aluminum club, and I'm still wary of their durability. Watch out for manufacturer's overhaul and inspection requirements on the composites.

Mags are not infallable, and their LCC is definitely greater than EI. The notion of one EI and one mag on an engine strikes me as silly if for no other reason than having two ignition systems to service with differing requirements.

There's no real performance advantage to FI except the ability to better balance fuel distribution and control hot cylinders. Thus you might save a tad on "mileage" but I doubt you'd ever recover the initial higher cost.

Please mail the two cents you owe me.

John Siebold

[Russ McCutcheon]

In your engine thread you specified it would be for IFR use. I would buy the fuel injected Lycoming from Van?s and the Hartzell to match from Van?s.

[gereed75]

Love my 200RV but CG is an issue. I would do the Hartzell if I had a do over, just for that reason.

[Captain_John]

I went with the Hartzell on my TMX-IO-360

Reasons were:

1) CG (as stated previously)
2) Cost is less than the plastic ones
3) Performs well!

Truth be told, nothing performs dollar per knot than a good wooden Sterba for $700 or so. But I am a button pushing cowboy and I like fiddling with things in flight as I get bored easily... hence I NEEDED a C/S prop.

I REALLY liked the PCU 5000 governor. I talked to Bob Hoenig from Ameritech Industries and set up a group buy for them back in the early days of this forum when we were allowed to do that. I got MANY PCU 5000's at a very reduced price and MANY (I think well over 100) people here now have those guvs on their planes.

If you aren't familiar with the PCU 5000, google it up. It is a FANTASTIC guv!

This is what it looks like with the polished Hartzell spinner!



CJ

[SteinAir]

Been there done that with most brands on many different RV's. Currently we're flying an RV7 with an Aero Composites prop that is quite nice. In the past I've flown behind and/or used on our own planes the paddle blade hartzell, sensenich FP, Irlbeck FP, Hartzell blended, WW, Catto FP and MT. As it sits today, if we buy a new prop it'll be a standard B/A Hartzell.

It depends on a few things...if you have a TD, then a metal prop up front is really nice to have for CG reasons...if you have a Nosewheel, then the composites are nice. In the end as others have pointed it it's really hard to beat the standard ole' Hartzell all things being considered. I've come full circle on props and am back to that as probably being the best out there overall (like I said, taking everything into consideration like price, installation, maintenance, long term viability, utility, etc..).

I love the composite props because they are smooooth, but so are the Catto and other wood/composite FP props, and my experience has been that MT's have almost universally been slower on almost any RV installation I've seen, but WW's have been pretty good - though not always noticeably faster than a B/A Hartzell. This is not the case for every engine on every plane and every person, but just a general overall consensus for your typical 360 powered RV.

I do not have any experience with the Harntzell Composite props so I can't comment on them, but Rob Hickman does and can comment with a good deal of experience.

Just my 2 cents as usual.

Cheers,
Stein

[dworl7]

Randy Lervold has some great stats on his site comparing many props on his RV.
Weight, db levels, vibration, acceleration and deceleration properties, a lot of great info there!

http://www.romeolima.com/RV8/Prop.htm

Dennis
Long time lurker
Some day builder!