Whirlwind 300 vs 330 series propeller / RV -14 dragger

[Jon Shaffer]

I’ve looked through the wiki…still need help. Anyone have data on the 330 series 3 blade Whirlwind, particularly in comparison to the 300 series 3 blade? It is apparent that the 36lb / 72” 300 series lends to aft CG issues. Has anyone installed the 56lb / 73” 330 series? I would assume it would balance out the CG much better but possibly be slightly slower in cruise / slightly better in climb. The price difference is around $1500 which I would be ok with if it kept the CG issues at bay. I Really don’t know much about props and am looking for some guidance. Engine is a 390-EXP119. Thanks.

 

[N667CD]

I’ve looked through the wiki…still need help. Anyone have data on the 330 series 3 blade Whirlwind, particularly in comparison to the 300 series 3 blade? It is apparent that the 36lb / 72” 300 series lends to aft CG issues. Has anyone installed the 56lb / 73” 330 series? I would assume it would balance out the CG much better but possibly be slightly slower in cruise / slightly better in climb. The price difference is around $1500 which I would be ok with if it kept the CG issues at bay. I Really don’t know much about props and am looking for some guidance. Engine is a 390-EXP119. Thanks.

2 blade HRT 74 works just fine on my RV14. 320+ hours, started flying 10/1/20.

 

[Jon Shaffer]

2 blade HRT 74 works just fine on my RV14. 320+ hours, started flying 10/1/20.

thx. I prefer the 3 blade, hopefully I can get some data on them.

 

[dmattmul]

It is apparent that the 36lb / 72” 300 series lends to aft CG issues.

Before I decided to use a lightweight WW prop I was able to obtain 5 builders W@B spreadsheets and after understanding each builders' complete options determined the WW300-3B-72 at 36 lbs would be ok. I even went with EarthX battery (2) on the firewall. Can I fly acro with more than 20 lbs of baggage, NO !! But why would I ? I've checked my airframe before and after paint with 2 different sets of scales. No issues with a 100 lbs of baggage utility CG. Acro and utility have different CG limits on the 14.

Apparent how ??

 

[Jon Shaffer]

Before I decided to use a lightweight WW prop I was able to obtain 5 builders W@B spreadsheets and after understanding each builders' complete options determined the WW300-3B-72 at 36 lbs would be ok. I even went with EarthX battery (2) on the firewall. Can I fly acro with more than 20 lbs of baggage, NO !! But why would I ? I've checked my airframe before and after paint with 2 different sets of scales. No issues with a 100 lbs of baggage utility CG. Acro and utility have different CG limits on the 14.

Apparent how ??

Thanks for you reply. “Apparent” is just my perception as I don’t know much about RV 14 propeller applications and am hoping to get some help on the matter. I dont want to be in a situation where I am compelled to add ballast weight in the nose, or extra batteries or alternator, or move the ELT etc to account for CG. That’s where my thoughts on the “apparent” aft CG with the lightweight WW arise. Wouldn’t putting a 53lb WW330 alleviate the aft CG issues without adding weight or moving components? That weight is very close to the aluminum 72” Hartzell that I bought through Vans. I do intend on a considerable amount of aerobatic flight and would like to keep the CG as neutral as possible, definitely not tending to the aft side of the envelope. I am hoping someone here with experience with the heavier 3 blade WW can provide performance data, or someone knowledgable enough can tell me why it is/isnt a good choice for this application. Thanks Again.