Prince Props

I own an RV-4 with an O-320, 160hp that came with a Prince propeller installed. This propeller always seemed over pitched, it would only pull about 2550 rpm flat out and static was 2050 rpm.

Feeling like I could get better climb and more top speed rpm I corresponded with MT propellers and Smokey Ray to find the best prop solution for my RV. My brother had just bought a new constant speed scimitar 3 blade MT for his Mooney, so I thought that MT would be the way to go, keeping light weight by going composite and staying fixed pitch.

Smokey was very helpful, sending me pictures of his MT prop, and giving me performance figures, albeit with a 0-320 that was modded for 170 plus horsepower. Thanks Smokey and thanks to MT for their great response to my inquiries! I really can't thank Smokey enough for all his emails and pictures.

In the interim, right before placing an order with MT, I talked to Lonny Prince about redoing my prop, cutting it down to provide more static rpm, hopefully improving climb and allowing the engine to run max horsepower. As I was doing an annual, my A&P removed the prop. I sent it to Mr. Prince in the Sensenich box that my hanger mate had just received the new prop for his RV-8 in. Mr. Prince said he could give me what I wanted, and the results were worth the wait.

I got the prop back and it was beautiful. I sent Mr. Prince a gray fiberglass prop and he returned to me a black epoxy masterpiece, with a urethane leading edge. After installing the prop I couldn't wait to hop in the plane and try it out. Unfortunately it was a pretty hot day but static rpm was up to 2200. I took off, climbed over the field, man, it felt stronger in climb but that's kinda subjective without measurements. Unfortunately I did not have much time to fly as I bungled into the gust front of a thunderstorm (did not see the storm due to heavy cumulus) and ran back to the airport with my tail between my legs to try another day.

Back to Smokey. Seems he sold his RV-4 to a friend at the airport. What a coincidence! Now we could really compare the performance between two RV-4's, one with 160hp and a Prince carbon fiber prop and the other 170hp with a fixed pitch MT. We flew against each other this week and there are some interesting differences. Smokey's old RV-4 is about 5mph faster. But I have to throttle back my RV-4 to stay in formation climbing out. I take off faster, I know because we took off four times in formation. And in a climb with Smokey's old RV in trail I can steadily pull ahead, it can't keep up. Of course, MT could easily make a prop with better climb characteristics. My point, is that Lonnie Prince makes a prop every bit as good performing as an MT, and it is much prettier, does that matter? I need to send in a picture.

So, there you have it. Thanks again to everyone. First to Mr. Prince for making such a fine product. Second to Smokey for all your help, and for selling your RV-4 to Demo. Don't count out Prince when buying a prop, he really is a great guy to work with, a real Prince. There, I had to say it.

Great write up! I'm looking forward to seeing your before and after numbers when you get a chance to do so. I'd also like to see a pic or two or your prop. I've been talking to Fred Felix about making me a prop in the next few months, but I'd like to see some more info on your Prince.

Thanks!

Good info!!

Rich,
Thanks very much for taking the time to submit your findings. I'm leaning toward the MT for my all manual, light weight O320 RV4 in the finishing stages (flying in 08'). The weather resistance of the MT has some advantages for the rainy northwest I live in. It sounds like Prince is a good way to go also. Choices are wonderful.

Sincerely,

Prop selection

I agree, it's great to have selection. On one post I remember someone saying they would not have a Prince prop so after comparing I wanted to let others know what a great option it is. My prop was originally a plain fiberglass one. Mr. Prince really did me a favor by covering mine with epoxy. I also wanted to relate what a gentleman he is to work with, and how he fit my specifications so perfectly when I asked for more rpm. What ended up astounding me was that my groundroll is shorter than the MT Smokey had on his RV-4 and my climb noticeably better while being about 5mph slower. I am still a big fan of MT, but my eyes were opened to how many good propmakers there probably are out there. Plus I saved $2000.00 by not buying another prop.

Forgot to mention

I forgot to add that another difference between the Prince and the MT prop was that the RV4 with the MT yawed a bit with power changes. My brother, who was flying Smokey's old RV-4 said maybe it was P-factor, that being a larger diameter prop may have made a difference. Remember, the Prince prop is 68 inches, versus the MT's? 72? Of course, two different airframes as well may be the difference.

Prop me up!!!

Hi Rich,

Nice write-up! The Bandit had 6 different props on it over the 12 years I owned it. For 9 years it had 150HP, the last 4 with the 170HP. What I found was everything in life is a compromise, especially props. I have flown a Sterba, Bernie Warnke, Margie Warnke, Catto, Gary Hertzler and the MT. The absolute best being the Gary Hertzler Composite prop. Gary builds props for Long-EZ's in his garage on a very small scale but he is an aerodynamicyst and his props are pure genius. I sold mine reluctantly to a friend in San Diego. The Hertzler tested at 8500' at full power on my 170HP 0-320 stock cowling, gear legs and wheelpants at 169 Knots true at 2640 RPM, 8.9 gph. The MT trues slightly less at higher RPM. Full Throttle at Sea Level 2720 RPM the Hertzler would indicate 210 mph consistently, VNE and still operate comfortably out of my short grass strip. What more can you ask of a design?
The MT Demo now flies was the best compromise in durability I found. Since I operated from a short, rough grass strip with gravel and sand, did alot of acro and cross countries, the MT was the best for that mission. However, the Hertzler is prettier and faster and climbed very well...I look forward to Demo hanging the new Hertzler prop in my garage on the Bandit for a different perspective. Again, excellent work Rich!

I now own a HR2 and kinda miss playing around with props, now I just go...very fast!

Here are some pictures of the Hertzler composite prop...

Smokey