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Video of 300 Series Constant Speed Propeller

https://www.youtube.com/watch?v=BI9Ts4pGyag

Check out the 300 series constant speed propeller: the lightest propeller in its class! Get better takeoff performance, higher rate of climb, smoother operation, and no compromise on top speed

Best Applications:
300-72" (36 lb): RV- 4, 6, 7, 8, 9, 14
- Engines: (I)O-320, 360, 390
300-77" (42 lb): RV-10
- Engines: (I)O-540 Straight Valve
Whirl Wind's newest propeller, the 300 series comes in 70-79" diameters ranging from just 36 lb - 42 lb with spinner and hardware included in the weight.

ACtC-3cpG1BZros8w2DMqHOitn6AH8tQvy2nsSqhLw6YlU4EarPWYuTiCcf43IwCx6kBo4F2RyCSSTAPxiMw0LcDHxI_tEqa9zQwVeUhN8Af-A7hzjizNBsIdt8LBNxiOnHlWAVeNFGjE67FuhkMuU-Ht_M=w500
ACtC-3dG3Dav56Bd21naxn3GBBnT_TYcpXmO4L6mGpzIVjvtdijwews6A22iZRTyrZGv_lWDKwVOHiAi4V9gu1YxGCo7Kxz7e5IzUj9JAbWTYRikepCNW0hP_lOnZrTQG4PbbKHvcYvxuBoMXjV09zOKmgPl=w350


KitPlane Article about the propeller with some performance comparisons: https://www.kitplanes.com/whirl-wind-300/

Propeller on Whirl Wind website: https://whirlwindaviation.com/props/300series.asp
 
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Prop

How do these compare to the 375RV that I have on my 10? They look similar except the tip design, mine is a sharper point.
And BTW I'm super happy with my whirlwind. Everyone comments on how smooth it is.
 
How do these compare to the 375RV that I have on my 10? They look similar except the tip design, mine is a sharper point.
And BTW I'm super happy with my whirlwind. Everyone comments on how smooth it is.

The HRT375 is about 55 lb compared to the 42 lb for the 300 series 77. That’s because the HRT propellers use an old McCauley based hub system and the 300 series is an all new Hub platform design. It packages smaller allowing it to be lighter and to fit better in the spinner (no more blade ferrules showing through the spinner blade cutouts). The 300-77 was designed specifically around the RV-10/IO-540 engine airframe combination. PIREPS say the 300 series offers better takeoff and climb performance, smoother operation, and no sacrifice on top speed.
 
I'm a gonna be needing one of those for my RV-8. Not ready to hang the engine yet. But, hopefully in about 6 months.

I'm wondering how far out should we be ordering? What kind of delivery time? And, What are the terms?
 
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I'm a gonna be needing one of those for my RV-8. Not ready to hang the engine yet. But, hopefully in about 6 months.

I'm wondering how far out should we be ordering? What kind of delivery time? And, What are the terms?

I order a 300-72 for my -8 build recently. Quoted lead time on initial contact was 4-6 weeks. In actuality, the prop shipped about 2 weeks after I placed my order; all told, exactly four weeks passed from the time I placed the order to the time I cracked open the crate at home. A $1000 deposit was required to place the order.
 
CG issues

Very intriguing. Would love to put one on the F4 (four cylinder rocket) I'm building but I actually will probably need the up-front weight for CG purposes. Won't know for a while if this is a real option for my (or similar) builds.
 
The HRT375 is about 55 lb compared to the 42 lb for the 300 series 77. That’s because the HRT propellers use an old McCauley based hub system and the 300 series is an all new Hub platform design. It packages smaller allowing it to be lighter and to fit better in the spinner (no more blade ferrules showing through the spinner blade cutouts). The 300-77 was designed specifically around the RV-10/IO-540 engine airframe combination. PIREPS say the 300 series offers better takeoff and climb performance, smoother operation, and no sacrifice on top speed.

Jim (I assume), could you tell the audience about your inflight strain gauge work?

https://whirlwindpropellers.com/aircraft/engineering/
 
Jim (I assume), could you tell the audience about your inflight strain gauge work?

https://whirlwindpropellers.com/aircraft/engineering/

This is actually Hunter (engineering at Whirl Wind Propellers).

We have a telemetry system that wirelessly transmits the strain data. So we use finite element analysis (FEA) to identify the expected high stress areas and the areas expected to be subject to harmonic excitation. The FEA analysis is very useful tool to calculate stress distribution trends and optimizing the structure before Mfg the prototypes.
We install strain gauges at the identified critical locations and record real time strains at various RPM's
 
RPM limitations

Are the RPM limitations the same?

Just wondering because I would think the interactions/hamonics between a 3 bladed prop and a 4 cylinder engine would be different than a 2 bladed prop and a 4 cylinder engine. (same question with 3 blades/6 cylinders or 2 blades/6 cylinders)
 
Are the RPM limitations the same?

Just wondering because I would think the interactions/hamonics between a 3 bladed prop and a 4 cylinder engine would be different than a 2 bladed prop and a 4 cylinder engine. (same question with 3 blades/6 cylinders or 2 blades/6 cylinders)

The RPM limit is the same (2700 rpm). The harmonics are based on the forcing function of the engine and the natural frequency of the blades. So the harmonic frequencies won't change from a 2 blade to a 3 blade (nor will natural frequency), just the magnitude of loading.
 
This is actually Hunter (engineering at Whirl Wind Propellers).

We have a telemetry system that wirelessly transmits the strain data. So we use finite element analysis (FEA) to identify the expected high stress areas and the areas expected to be subject to harmonic excitation. The FEA analysis is very useful tool to calculate stress distribution trends and optimizing the structure before Mfg the prototypes.
We install strain gauges at the identified critical locations and record real time strains at various RPM's

Thanks Hunter. Nice to meet you.

Have you had an opportunity to look at strains with high compression pistons and/or some of the more aggressive ignition advance schedules? There have been a few prior hub and ferrule issues with those engines.
 
Thanks Hunter. Nice to meet you.

Have you had an opportunity to look at strains with high compression pistons and/or some of the more aggressive ignition advance schedules? There have been a few prior hub and ferrule issues with those engines.

Dan, yes there are a few limitations for the 300 series: Angle valve 360 and angle valve 540 engines are NOT suitable for this hub system. Max RPM for this propeller series is 2700 rpm and the approved compression ratios are:

(I)O-320 9.6:1 Max
(I)O-340 9.6:1 Max
(I)O-360 8.5:1 Max
(I)O-370/375 CW Crank 9.6:1 Max
(I)0-370/375 No CW Crank NOT SUPPORTED
(I)O-390 9.6:1 Max
(I)O-540 9.6:1 Max

As far as ignition timing goes: we have seen that high MP and advanced ignition timing can increase the stresses, but this is an area of continued research and as of now we do not have any additional operating limitations or ignition timing restrictions as long as you are using an approved engine with approved compression ratio.
 
Dan, yes there are a few limitations for the 300 series: Angle valve 360 and angle valve 540 engines are NOT suitable for this hub system. Max RPM for this propeller series is 2700 rpm and the approved compression ratios are:

(I)O-320 9.6:1 Max
(I)O-340 9.6:1 Max
(I)O-360 8.5:1 Max
(I)O-370/375 CW Crank 9.6:1 Max
(I)0-370/375 No CW Crank NOT SUPPORTED
(I)O-390 9.6:1 Max
(I)O-540 9.6:1 Max

As far as ignition timing goes: we have seen that high MP and advanced ignition timing can increase the stresses, but this is an area of continued research and as of now we do not have any additional operating limitations or ignition timing restrictions as long as you are using an approved engine with approved compression ratio.

Thanks Hunter. Question please. If angle valve 360 engines are not allowed with this hub, how did the 390 get approved?
 
All the common angle valve models have pendulum absorbers, 4 and 6 cyl.

Thank you for bringing this up. Angle valve 360’s need counter wt’ed crank shafts, straight valve 360’s do not. We will make note to update this on our website:

Engines for 300 Series Propellers:
(I)O-320: 9.6:1 Max Compression
(I)O-340: 9.6:1 Max Compression
(I)O-360 Parallel Valve: 8.5:1 Max Compression
(I)O-360 Angle Valve with CW Crank: 8.7:1 Max Compression
(I)O-370/375 with CW Crank: 9.6:1 Max Compression
(I)O-390: 9.6:1 Max Compression
(I)O-540 Parallel Valve: 9.6:1 Max Compression

(I)O-540 Angle Valve (300hp) not recommended for the 300 series propeller (For this engine we have the 375HRT and 378HRT propellers).
 
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