Is it true that the Japanese Zero fighter actually had a Pratt and Whitney emblem on its engine?
Was the Nakajima NK1F Sakae 21 a copy of the Pratt & Whitney Twin Wasp?
Just curious.

They were told to copy the engine, and they did. You can see the placard on the Zero in the Naval musieum in Pensacola. It is not a crisp copy though, but the bird is there.

Tom

There is a possibility that the Zero in the museum was reengined for flight testing or was rebuilt from an incomplete airframe. The Japanese had their own engine development programs. Although they did at times purchase manufacturing rights from various companies they often substantially modified products for their needs and manufacturing techniques. Rambling aside, if you are modeling a specific airframe that has a P&W lable on the engine than it would be to scale.

A little further research indicated that the engines may have some P&W ancestry. However other sources cite that the engine was based on a license built Gnome Rhone 14. I also found that that propellor was based on a Hamilton standard design, the machine gunes were a Vickers design and I seem to remember that the cannons were either Oerlikon or Hispano.

While we're rambling...

Around Caterpillar (and I understand, some SeaBees reunions) there are stories about South Pacific island hopping US personnel finding Cat D-3 copies (if I remember the model number correctly.) The stories I heard (admittedly, secondhand) tell of copies complete with the logo on the emblems.

Personally, I was on a team that worked with some Swedish engineers who told this tale. Sweden was neutral, and had their own air force during WWII. They tried to buy P&W radials, but the US couldn't spare any for them. They asked to license-build them, but were not allowed to do that either. So, they simply reverse-engineered an engine, and produced them as needed.

The story continues that after the war they packed up one of their copies and brought it to P&W, explaining that they had made these copies during the war, and now wanted to pay licensing fees on them. The copy was mounted in a dyno and found to produce the same power as the P&W. (The old guy telling the story actually said "One horsepower more!" )

According to this guy, the P&W folks came out of committee and signed off on the built engines for a total fee of $1.00 US. I didn't ask what nameplate they put on the engines.

Cheers,
Dave Olson
(edited for some of the typos)

While we're rambling...

My uncle toured a surrendered German Uboat in 1945 and he says the control room
had Crane valves in it.

I saw a genuine Me-109 tailwheel in a museum with the word CONTINENTAL in the rubber

Before the war, numerous Japanese engines, vehicles and components were license built from Western designs. Mazda produced GM truck designs, Sumitomo produced Hamilton Standard propellors....and so on.

I was once told that early Toyota and Nissan 4-bangers in the late 60's and early 70's were US designs that were never introduced Stateside during the economy fad that almost occurred in the early sixties. The Japanese manufacturers improved and "perfected" some designs and you know the rest. On the other hand, the German DB-601 license built inline engine was plagued with troubles.

Since new radial engines introduced by Japan during the war were somewhat unreliable, and parts for the "good" ones would be impossible for the Allies to obtain, I'll bet the P&W plate is on a P&W installed for this reason.

As I recall, the Nissan 4-cyl engines (Datsun) of the late 60's and early 70's were similar enough to the British BMC engines that some of the parts were interchangable, eg, heads.

The Zero in the Naval Aviation museum in Pensacola was "restored" (term used very loosely) by Bob Deimert in Canada and was fitted with an R-2600 when restored. I'm going to say that if it still has a P&W placard on it that's because it is a P&W and not the original Sakae.

Isn't the R-2600 a wright eng? Jason Somes who fly's the CAF Zero told me the Sake eng is basicly an R-1830 P&W.

Duh! [X(] You're right of course, the R-2600 is a Wright and not a P&W. My sources state that the airplane, as restored by Deimert, was fitted with an R-2600. However, if you look at the airplane as it is on display now it appears that the cowl has changed since the Navy took ownership. The 2600 won't fit in the original cowl so Deimert used a larger one, I think from a B-25. It looks like it now has a more stock looking cowl on it so the Navy probably jerked the R-2600 out and stuck in something else to fill up the hole, possibly an 1830.

Planes of Fame have a flying Zero with a Sakae engine in it, but i think it is a later version. Maybe they could answer the question?

Tom

If I recall some of research that I have done on the Zero, the engines on the A6M2 were copies of the P&W (down to a data plate that was painted over) It my understanding that PW did grant licensing rights to Japan before the war. The orginial propellors were Hamilton Standard right down to the counter weights. Later Zero versions had the Sakae engine that was extensivly reworked to try to improve performance.

The Nakajima Sakae is not a P&W copy, none of the parts are interchangeable. The bore and stroke are also different, the closest American engine would have been the P&W 1535 that powered the HH-1