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Old 02-26-2016, 10:51 AM   #11
Bob Gardner
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Biggles,

Can you tell us anything about the prop. Did you restore it or have it restored it?

I think it is probably a genuine prop. Reproducing exactly the laminations found on a genuine prop would be an unlikely achievement.

With kind regards,

Bob
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Old 02-27-2016, 02:52 AM   #12
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I have had a closer look at the Prop and the marking on the first picture shows:
JN.4H
150.HISPANO.SUIZA
PITCH.VARIABLE.
DIA.7" 8"

The second shot is of the blade tip, which is a sort of green coloured paint or material.

The third shot is of the back of the blade.

The fourth shot is just to show how nice the wood shapes into the Hub.

The length is 91 Inches and the Hub diameter is 8 1/2 Inches.
Hope this helps.
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File Type: jpg IMG_7034.jpg (90.2 KB, 17 views)
File Type: jpg IMG_7038.jpg (87.6 KB, 13 views)
File Type: jpg IMG_7039.jpg (91.8 KB, 13 views)
File Type: jpg IMG_7040.jpg (91.4 KB, 13 views)
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Old 02-27-2016, 02:57 AM   #13
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Hi Bob, I just saw your question. No, I did not touch it. This is the way it came out of the cloth that was wrapped around it. Obviously never been used. It was found on the rafters of an old garage in Kent and bought by a Collector, who in turn sold it to me.
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Old 02-27-2016, 08:44 AM   #14
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Hi,

IMHO, if you paid more than some pounds for it, you have to claim for a refund. With this length (91", ~231 cm) it is not even a replica but a decorative thing, probably made in Asia after 1980 (and perhaps last year!).
The fact it is stamped and a mimic decal was put on it is clearly misleading and, perhaps, the seller could be sued.
Just my opinion!

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Old 02-27-2016, 09:33 AM   #15
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Biggles,

You have inadvertently led me a merry dance, full of vacillation!

I have tended to think, with some reservation, that your prop is a genuine WW1 prop. But last night whilst puzzling about it, particularly about the colour of the wood, it occurred to me that I have been here before. About fifteen years ago, when I dealt in WW1 propellers, I was offered about six, two of which were genuine and four of which were modern replicas, although convincing. I didn't buy any of them. What passes for my memory, connected that the colour of them were similar to yours. Later I was contacted by makers of replica props by makers in the Philippines and in Korea. I have just googled this but have not found one exactly like yours. But last night it tipped me into thinking yours is a replica.

Now that you have given us the data above I return to the inclination that it is genuine because;
the diameter of 7'8" is exactly right for the SPAD S7 with the 150hp Hisso.
the term variable pitch does not imply the modern connotation, but simply that various pitches were tried or available with this prop. The term only occurs in the depths of one of my obscure databases, annotated to a propeller made by Ebora, drawing numbers 95 and 95A.

I don't think one of the Far East makers of replicas could get all of that right.

In passing, the British subsidiary of Integral made a prop of similar dimensions for the SPAD S7 to a design of Levasseur, IPC 2391, but I have no record of the term variable with one of these props.

So I conclude, after some oscillation, that your prop is genuine, but has been stripped and restored. Possibly the similarity in colour with modern replicas comes down to the use of similar modern lacquers. Nonetheless it is enigmatic.

Thank you for the intellectual challenge!

With kind regards,

Bob
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Old 02-27-2016, 11:02 AM   #16
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Postscript;

I don't know what JN 4H means.

I enclose a photo of the original Ebora drawing number 95A prop for the SPAD S7. Note the shape of the hub. Its unusually tall or deep and matches the shape of yours.

Ginger
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Old 02-27-2016, 11:29 AM   #17
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And here is a photo of the data on a hub from this propeller. There's rather a lot of it, much more than the usual Ebora presentation of data. Normally Ebora data was rather minimal.

Note the yellow arrow which points to the small letters EN.B in the same font, I think, as JN. 4H on yours.

I will tentatively add to this drg no. (in my database) a note that one example carried an atypical Levasseur decal.

With kind regards,

Bob
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File Type: jpg 1165 SPAD hub 2 reduced.jpg (97.0 KB, 14 views)
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Last edited by Bob Gardner; 02-27-2016 at 11:45 AM.
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Old 02-27-2016, 12:03 PM   #18
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Bob, do you think that this prop might have been a reproduction intended for a Curtiss JN4H (which used the Hisso engine, i.e. "H" after JN4)? I realize the JN.4H could be coincidental, and I know it's a bit short for the Jenny, but seeing an obvious aircraft model stamped on the top of the hub stampings makes me a bit suspicious that it was made for something else.
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Old 02-27-2016, 01:30 PM   #19
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Hi Dave,

Ebora made a prop for the Curtiss engine used on the JN4 and the DH6 of the Royal Navy, but not for a Hisso engine on the JN4.

There was a British drg no. for the JN4H with the 150hp Hisso engine, 34889. I don't know what this number represents but similar numbers cover a range of British numbers for American aircraft used by the British, almost all by the Royal Navy.

It might be that an Ebora prop of this design was tried on a 150hp Hisso on a JN4, but I'm inclined to think that the small font of both JN.4H and EN.B indicate that it was of minor note and perhaps some sort of internal Ebora reference. But this is entirely a guess from me.

With kind regards,

Bob
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Old 02-27-2016, 09:33 PM   #20
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Hi Guys, it is getting more and more interesting. Fake?, genuine?, I'd like to think that with the history how and when I bought it, it has to be genuine. I was starting to believe that the SPAD was the no 1 candidate but then with the JN.4H printed on it, it may well have been made for the Jenny, (as was mentioned to me when I bought it).
See these references:
JN-4H two-seat advanced trainer biplane with ailerons on both wings, 929 built for the U.S. Army, notable for introducing the use of the Wright Aeronautical license-built Hispano-Suiza 8 V-8 engine for greater power and reliability.

Like the re-engined 'JN-4H' version of the most-produced JN-4 subtype, the final production version of the aircraft was the JN-6, powered by a Wright Aeronautical license-built, 150-hp (112-kW) Hispano-Suiza 8 V-8, first ordered in 1918 for the US Navy.

After the successful deployment of the JN-3, Curtiss produced a development, known as the JN-4, with orders from both the US Army and an order in December 1916 from the Royal Flying Corps for a training aircraft to be based in Canada.[N 1] The Canadian version was the JN-4 (Canadian), also known as the "Canuck"

The Wright-Martin built Hispano-Suiza engines incorporated some improvements made by Wright engineers in 1922, although they had to be derated to 150 hp to be of any use. Whereas, the French production models produced 180 hp from the start.3 The Wright built engines were of too little power for combat use and some went into Curtiss JN-4Ds.

Over to you.
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