RV74 prop

sailvi767 · #1 02-06-2014, 06:30 PM

I wanted to post a bit about switching from a RV200 to a RV74 prop. We had about 250 hours on a RV200 prop. The hub was starting to spit grease on hot days so we contacted Whirlwind in Ohio. They discussed a change in seal material and grease that was causing the issue and offered to rebuild the hub and prorate the cost to their normal overhual cycle. I felt this was a fair offer and we made plans to fly the aircraft up to Ohio.
In my conversation with them they mentioned the RV74 prop they now had available. The prop was optimized for 200 to 230 HP applications. I was very happy with the RV200 blades but got a quote on the newer blades. Since the blades have to come off for the hub overhaul there were no installation costs to switch the blades. They offered a very reasonable price to switch the blades and we got to keep the RV200 blades as spares. We decided to make the change.
I flew the aircraft up several weeks ago. We did several other mods to the aircraft when we got it back and just now have been able to get a bit more hands on time with the new prop. We also had it dynamically balanced today by Mike S at Goldhill. He did a great and quick job for a very reasonable price.
The visit to the factory was interesting as they make both the Whirlwind props and the Titan Mustang kits. I enjoyed getting a chance to check out the mustangs. I noticed one was a bit larger then the Titans. He mentioned it was a full sized mustang prototype they are working on that may become a kit. I asked where they got the plans for a full sized airframe and he replied "North American". They are building the aircraft from the original plans!
The prop hub overhual and blade switch went well. The people at Whirlwind offer great support.
The prop itself looks great on the aircraft and the performance has been excellent. I typically would see 182 to 184 knots true AS in the 7500 to 9500 foot range. The new prop seems to have added about 4 knots which is a nice improvement. Today we were holding a solid 189 knots TAS at 8500 feet 100ROP. 40LOP produced 177 knots true at 8 GPH! The bigger improvement seems to be climb. The prop really pulls. Sadly I never actually timed any aircraft climbs so the increase in climb rate is subjective however both my partner and I feel the aircraft has a noticeable increase. Solo on a cold day now this thing just leaps into the air! I should have made a few timed runs and noted the conditions since when you spend money you have a desire to see a positive outcome that can color perceptions. I think there is a very noticable improvement. The prop also is very smooth since the balance. Overall we are very happy with both the looks and performance!

George
RV6, ECI IO360 10-1 pistons, Dual lightspeeds, ECI injection.

rv6rick · #2 02-06-2014, 07:16 PM

Thanks for the report and congrats on your new blades. I'd expect nothing less from Whirlwind

!

sailvi767 · #3 02-07-2014, 06:09 PM

Pic of the new prop.

grayforge · #4 02-09-2014, 02:32 AM

beautiful prop!

You mentioned that you did a few more mods in addition to the prop. Would any of them have had anything to do with the speed increases you saw? Just wondering if the speed bump was all prop or aided by the mods.

Thanks!
Russ

grayforge · #5 02-18-2014, 02:49 PM

I just placed an order for my 74RV. Unfortunately, I have no idea what my plane's color scheme will be. I'll have to pick a generic color, so it won't be as beautiful as your prop.

sailvi767 · #6 02-18-2014, 03:49 PM

Quote:

Originally Posted by grayforge

beautiful prop!

You mentioned that you did a few more mods in addition to the prop. Would any of them have had anything to do with the speed increases you saw? Just wondering if the speed bump was all prop or aided by the mods.

Thanks!
Russ

We did add a oil separator along with the vacuum attachment from antisplat. I flew the aircraft with the new prop only once before we made the addition. I know they claim additional HP with that mod but there was some extra speed on that flight and I am skeptical about HP gains.

George

grayforge · #7 02-18-2014, 04:01 PM

Good to know. I also have the anti-splat Air/Oil Separator and vacuum valve to be installed.

Romeo Victor · #8 03-07-2015, 01:05 AM

Hi George,
I am building my second RV8 here in Germany, close to Munich. I am in contact with Aerosportpower for the IO375, low compression with 195 hp and like to install the WW74RV.
1. Do you have any info that this combination could cause any trouble, especially when using the LSE ignition system and possible vibration problems for the prop?
2. Would you recommend to install a counterweight on the crankshaft?

Take any advice
Thanks for answering
Stephan

Randy · #9 03-07-2015, 07:11 AM

Stephan,

I am using the IO-375 with WWRV200. Before the purchase, I called Whirlwind to ask about the combination. They really liked that I had the low compression, and said that a counter weighted crank would be even better..

Randall in Sedona

Sylvainsting · #10 05-22-2015, 11:55 PM

Hello,

I'm building a RV7 in France and plan to install a 74RV. My question is: There is 2 extra inches from 200RV to 74RV. Could it be a problem for a RV7 tail wheel ?
I've heard some people asked to Whirl Wind to cut 2 inches from the 74RV. Is it possible to touch the ground with a 74" ?
Any informations about that ?

Sylvain