Catto, the "Great-O..."
Back in the 90's I tested Craig's first 2-Blade and later an early 3-blade on my RV4.
I compared the two and three blades directly with my original Sterba 2 blade and a later a pair of Warnke (both Margie and Bernie)"almost constant speed" props as well as a Sensenich metal, Hertzler, MT fixed pitch and 3 other Catto test props. Many years later I would test one of the first Catto Gen-II 2-blades on my RVX. My data is nearly 20 years old but still relevant inasmuch as the Theodorsen theories are timeless.
Observations:
1. Two blades are faster than three, every time. I tested at low and high altitude and the results always favored the 2 blade. (original design)
2. Three blades cost more than two. $$$ (Nuff said)
3. Hand propping a three blade with a dead battery is more challenging than two.
4. Three blade props climb better and are smoother and a bit more quiet.
5. The 3 blade had higher coefficient of drag throttled back. (glide and in the traffic pattern) than 2.
Overall winners for my 170HP 0-320 powered RV4.
Flat out speed (WOT): Margie Warnke "Claw" Hands down.(great prop, sadly, She is retired)
Climb, cruise efficiency, second fastest. Gary Hertzler "Silver Bullet" (special order on a case by case basis).
Climb, Aerobatics: Catto 3 Blade. (original blade design)
*Best overall compromise prop for speed, utility, climb, STOL, aerobatics, rain,
cost and longevity: Catto Two Blade with LEP
Recommendations: Craig Catto is an awesome guy and good friend. You can't go wrong with his product. On a tighter budget? Ed Sterba is hard to beat and a great guy as well. If you want a technically better prop that requires care in rain, buy a Hertzler Silver Bullet.
For me, I'd go with a 2 blade Catto every time.
V/R
Smokey
Notes: A. *Worst prop I tested: Sensenich Metal FP 2 blade. Heavy, noticeable flywheel effect, not aerobatic approved (By Sensenich) and RPM limited at 2600.
B. Axel and many others are flying Craig's latest 3 blade on their RV's with excellent performance matching or exceeding the 2 blade from what I've read.