Real-world New Prop Experience

[AA5Bman]

Does anyone have any real-world experience putting a new prop on their plane? Did it impact performance?

The prop on my plane seems tired. It may just be cosmetic, but I do wonder about replacing it every so often.

It’s an old McCauley, probably designed 40 years ago - or more - and could be replaced by a new MT or Hartzell Trail Blazer as an example. I’m really curious if anyone has gone down this road and can comment on differences in performance between the old and new designs - on one hand, I take performance improvement claims from manufacturers with a grain of salt, but on the other, I have to imagine our ability to model and design these things has come a long ways, and the prop is an obviously important part of performance.

Would love to hear comments if you have done this before.

 

[donjohnston]

I replaced the old prop on my 182-RG. Same type of prop though. The old one was pretty ratty looking. Years of filing down nicks probably reduced the chord of the prop a bit. I didn't notice any difference in the performance.

My Velocity has an MT prop. I would have replaced it in a heartbeat if it weren't for the cost. MT service and the two authorized service centers I dealt with made me want to throw the prop in the gulf. Maybe they're different on the certified side of the house. At the time I was building, MT was the only game in town. Fortunately (for Velocity's), there's an alternative now.

 

[Racerx]

I doubt design has changed much. Unless youre going to a composite or scimitar. Years of filing nicks and an overhaul or two definitely effects things.

 

[Bell206]

Does anyone have any real-world experience putting a new prop on their plane? Did it impact performance?

Define "impact performance"? If be new you mean buying a new prop that has a different diameter and pitch then yes you can seen a difference in performance which can be either positive or negative. However, unless your aircraft/engine has a diverse number of prop options, you may not have much choice on what you can install. Perhaps post your current prop specs and those available for your aircraft to see if any comparisons can be made.

 

[midwestpa24]

My only experience was going from an old prop that went off for OH and was rejected because it exceeded tolerances, to a factory new prop. I couldn't quantify the difference in performance, but it did seem to perform just a little better. Maybe 50-100 fpm in climb, another kt or two in cruise. Could have been a placebo effect, but it at least seemed like something was a little different.

It makes sense, many years of use, filing, dressing, the blades do wear down some amount eventually. I doubt it is much percentage-wise, but it could reduce peak efficiency.

 

[chemgeek]

Performance (e.g., speed) will be primarily influenced by pitch and the available engine power to drive the propeller. I wouldn't expect any significant performance change for a prop of the same pitch and diameter as the original. I did see a large change in performance when upgrading my engine to high compression pistons (via STC), which required a different (higher-pitch STC'ed) prop to fully take advantage of the extra power. In this case, the STC prop is slightly shorter and has beveled tips to slightly improve climb performance relative to the original design prop, while maintaining extra pitch for cruise. But mainly it's the 4 extra inches of pitch that drive performance. The STC engine has enough extra power to drive the extra pitch to redline at cruise, resulting in significant extra speed.