Hi everyone!
What was the purpose of cuffed props? Did the cuffs have something to do with airflow to the engine? I always think back to how early P-47s had the Curtis props with cuffs and then later had the Hamilton Standards without cuffs. Same with the P-51. The early Allison-powered Mustangs had no cuffs, the Merlin-engined ones had cuffs and then in the Korean War they primarily (not all of them) had cuffless props.
Thanks for everyone’s input!
Eric
why they’re to make you look all spiffy when you go on formal flights… 
sorry couldnt resisit… I haven’t a clue
I believe some were for improving the cooling of the radial engine fighters. Why they were on the early Mustangs I really don’t know but suspect it may have to do with the aerodynamics of the air flow around the prop. I’m sure someone out there will come up with some documented info!
Hey Melgyver - you are correct. The cuff was to increase airflow across the piston heads.
In WW2 were the U.S. planes the only ones that had them? I don’t recall seeing any on the German, Japanese, Italian, nor British planes.
Awood23, you raise a good point. I wonder if Howard Hughs’ plane had diamond cuff links on them. LOL!
Eric
The P-51 got propeller cuffs when it went from the Allison to the Merlin, in the belief that they improved propeller efficiency. However, because of the shortages of the Hamilton Standard prop, the P-51K built at the Dallas factory got an Aeroproducts prop without cuffs – depending on who’s doing the reporting, performance was not affected to a measurable degree or it was, in addition to an increase in vibration.
Spinners and cuffs became popular with designers to reduce drag, improve propeller efficiency, and – on radial engines - improve engine cooling. However, the spinner was deleted from the F6F and even more interesting, NACA determined that deletion of the spinner and cuffs on the B-26 Marauder resulted in lower powerplant drag and better engine cooling. There are other examples, some probably due to maintenance not wanting to bother with reinstalling the things.
Cuffs were a midwars development, improved fixed propeller efficiency. When they developed variable pitch props…they became a variable drag…[:)]
You guys are a wealth of information! Thanks for all the info!
Best wishes,
Eric
you guys make learning fun … thank you … [swg]