P-47 PROPELLER ( Hamilton or Curtiss Electric?)

[Tolga ULGUR]

Hi

I am working on P-47 D25 42-26643 "The Virgin".

In the beginning, my only reference was Aeromaster's 48099 decal sheet. Due to the explanation, this Thunderbolt has Curtiss Electric symetrical propeller , although all D25s are equipped with Hamilton std in the factory . But in the reference photos the prop looks like Hamilton std to me. What do you think about this? I'm thinking of using Hamilton std

Thanks in advance

 

[Tolga ULGUR]

1 hour ago, MARU5137 said:

This is from BM forum.

 

https://www.britmodeller.com/forums/index.php?/topic/234989098-curtiss-prop-p-47-question/

 

 

Thanks for the link

But I know and I have some sources about which propeller used in which versions.

My question is, does the propeller you see in the black and white pictures look like Hamilton or Curtiss?

If Aeromaster hadn't mentioned the Curtiss propeller, I wouldn't have questioned this as much and would have continued with Hamilton std .

Thanks

[KUROK]

I have seen Curtiss Electric prop on P-47s all having the cuffs.  Also the early Curtiss prop is sharper at the tip.  Later version of the Curtiss props on the P-40 had a wider chord and a more rounded tip.  In your photo it appears that the blade tip is more rounded and seems to have the cuffs.  So I do think this might be the wide chord Curtiss Electric.  At least this is my humble opinion...

Edited January 2, 2022 by KUROK

[KUROK]

Tolga, I just changed my mind.  ^

[Tolga ULGUR]

1 minute ago, KUROK said:

Tolga, I just changed my mind.  ^

Yes, thanks for your reply

[KUROK]

Does John Payne hang out at this forum?  He knows a lot about P-47.

My question is, do the Hamilton Standards ever show the "cuffs" on the P-47?

[Juggernut]

I believe the prop in the photographs is a symmetrical Curtiss Electric prop. I can clearly see the cuffs at the base of the blades which the H-S prop does not have.

Edited January 2, 2022 by Juggernut

[Tolga ULGUR]

22 minutes ago, KUROK said:

I have seen Curtiss Electric prop on P-47s all having the cuffs.  Also the early Curtiss prop is sharper at the tip.  Later version of the Curtiss props on the P-40 had a wider chord and a more rounded tip.  In your photo it appears that the blade tip is more rounded and seems to have the cuffs.  So I do think this might be the wide chord Curtiss Electric.  At least this is my humble opinion...

 

15 minutes ago, Juggernut said:

I believe the prop in the photographs is a symmetrical Curtiss Electric prop. I can clearly see the cuffs at the base of the blades which the H-S prop does not have.

Thanks a lot for your replies, appreciated indeed

[Tolga ULGUR]

33 minutes ago, Jennings Heilig said:

That's definitely a Curtiss Electric prop.  P-47s with Ham Stan props didn't have a cuff on the blades.

Thanks a lot Jennings

Thus it seems that explanation of Aeromaster set is correct.

[Juggernut]

To continue the discussion and In my opinion based on reading the referenced text, the most common cause that would result in a H-S prop being substituted for a Curtiss Electric prop (or vice versa) is an engine change.  The R-2800-59 can be converted from one type to another but not without some effort.  To convert a H-S hydromatic to a Curtiss Electric would require removing the distributor valve from the spline shaft (prop shaft) and replacing it with a plug (since the Curtiss Electric prop did not use oil pressure to affect blade angle changes).  The propeller governor would also need to be replaced, and lastly the electrical and mechanical components of the CE prop itself would need to be installed (slip ring, manual control switch (cockpit switch), wiring, etc.) (White, 321-330). 

 

With respect to bubbletop jugs only, I'll venture to say that the change from H-S to CE was accomplished because of the supply of the H-S prop ready R-2800-59 engines dried up (the -27-RE was the last P-47 built with a factory H-S prop (615 airframes) and there were thousands more CE propeller equipped P-47D's than H-S equipped P-47D's (5,293 CE vs. 1,000 H-S (White, 399-402)).  I don't have production numbers for the particular H-S prop used on the -25/-27 P-47D's (24E50-65) but any shortages of that propeller may also be a reason for the change. 

 

As a final note, the propellers on the C series engines, R-2800-57, 71, 77, and -81 engines (P-47M and N) were not interchangeable with the B series R-2800-59 engines (P-47D), no matter how similar they may look.  The prop shafts were different sizes (60 series spline for the C series R-2800's and 50 series spline for the B series engines) making the change impossible (White, 279-280).  On a model...that's another story.

 

REFERENCE: 

 

       White, G. (2001). R-2800, Pratt & whitney's dependable masterpiece. Warrendale, PA. pp. 279-280, 321-330, 399-402.

Edited January 2, 2022 by Juggernut

[Tolga ULGUR]

56 minutes ago, Juggernut said:

To continue the discussion and In my opinion based on reading the referenced text, the most common cause that would result in a H-S prop being substituted for a Curtiss Electric prop (or vice versa) is an engine change.  The R-2800-59 can be converted from one type to another but not without some effort.  To convert a H-S hydromatic to a Curtiss Electric would require removing the distributor valve from the spline shaft (prop shaft) and replacing it with a plug (since the Curtiss Electric prop did not use oil pressure to affect blade angle changes).  The propeller governor would also need to be replaced, and lastly the electrical and mechanical components of the CE prop itself would need to be installed (slip ring, manual control switch (cockpit switch), wiring, etc.) (White, 321-330). 

 

With respect to bubbletop jugs only, I'll venture to say that the change from H-S to CE was accomplished because of the supply of the H-S prop ready R-2800-59 engines dried up (the -27-RE was the last P-47 built with a factory H-S prop (615 airframes) and there were thousands more CE propeller equipped P-47D's than H-S equipped P-47D's (5,293 CE vs. 1,000 H-S (White, 399-402)).  I don't have production numbers for the particular H-S prop used on the -25/-27 P-47D's (24E50-65) but any shortages of that propeller may also be a reason for the change. 

 

As a final note, the propellers on the C series engines, R-2800-57, 71, 77, and -81 engines (P-47M and N) were not interchangeable with the B series R-2800-59 engines (P-47D), no matter how similar they may look.  The prop shafts were different sizes (60 series spline for the C series R-2800's and 50 series spline for the B series engines) making the change impossible (White, 279-280).  On a model...that's another story.

 

REFERENCE: 

 

       White, G. (2001). R-2800, Pratt & whitney's dependable masterpiece. Warrendale, PA. pp. 279-280, 321-330, 399-402.

Thanks a lot for the detailed explanation.

[swede]

Hey Guys, all of this has been great reading but I have a question. Who makes 1/24th scale HS Jug props? Fella is offering the proper prop hub but says the kit props are wrong for the hub. Great but, I can't find anyone offering aftermarket props. Any info available on this?? Thanks......

[Juggernut]

Don’t have any idea of the availability of 1/24 scale P-47 Hamilton Standard propellers.  Seems a bit odd to offer just the prop hub without the blades.

[Tolga ULGUR]

8 hours ago, swede said:

Hey Guys, all of this has been great reading but I have a question. Who makes 1/24th scale HS Jug props? Fella is offering the proper prop hub but says the kit props are wrong for the hub. Great but, I can't find anyone offering aftermarket props. Any info available on this?? Thanks......

 

All I know is that Model Monkey has a propeller hub.

 

[swede]

Yes, the hub I was speaking about. I don't understand offering the hub that the kit parts can't work with. I am totally impressed with the effort, but..........