Whirlwind 300 series on IO-375 limitation

[agent4573]

Doing research for next year's build, and were basically settled on the IO-375. Finding a prop for it is the issue. I really like the idea of the whirlwind 300 series, which was originally advertised for use on the 360, 375, and 390. There's a big red update on whirlwinds site now that says "as of 7/19/2019 this prop is no longer approved for the 375". I emailed them and got a generic reply of "while a 3 blade prop for the 375 is on our list of future projects, we're not working on it now and have no idea when we will".

Anyone know what happened to uncertify the prop for this engine? Besides the MT 3 blade, are there any other CS 3 blade props that are available for the 375? I've asked aero performance what they recommend and they wouldn't give a recommendation, said I needed to talk to individual prop manufactures directly.

[N941WR]

I don't believe any of their props are "certified". So, it's not a matter of, "uncertify the prop".

Certified props go through extensive vibration testing and analysis. Any change in stroke, compression ratio, ignition, cylinder head design, etc. can change the vibration profile of the engine/prop combination.

It is possible WW recognized an issue with this prop and engine combination that wasn't present with other engines and decided the 375 and their prop are not a good mix.

Bad harmonics can cause premature engine component failure and/or prop failure.

Good for them to change their recommendation!

[agent4573]

My bad, certified isn't the right word. It's no longer "approved" for use on the 375.