TriangleP wrote:
Very interesting engine. 262crew, the link I've posted here is something you most likely know already, but it shows some additional photos that give others some idea of the double shaft configuration. There was a lot of research then to push the engine output. A Napeir Sabre engine is another solution that utilizes 24 cyliners, but in an H configuration.
The NMUSAF photo shows the exhaust manifolds attached in the wrong direction, if, as the photo caption asserts, that this engine was used in the P-75. The overall configuration looks right for the P-75, with an appropriate reduction box you'd see on an aircraft. Its also possible that this engine is a test article, and not used in an intallation, so the manifolds were placed for convenience only, maybe? to redirect the exhaust in some manner consistant with a test rig structure. Or they have it screwed on incorrectly.
http://www.enginehistory.org/w3420.htmThis photo shows a close up the the engine casing seen from head on. To my eye, the engine case looks to be a single casting, but a closer examintation or engineering drawings would prove that either way.
http://www.enginehistory.org/Gallery/Ji ... 201-18.JPGNeed some POF people to provide some shots of their engine!
Thank you, the fist link you posted
http://www.enginehistory.org/w3420.htm has some very interesting info. I like the idea of the 3420-7 looks like it could have been used in something like the flying pan cake (Vought V-173 / XF5U-1)?
From that link.
"The W-3420‑7 was another arrangement for keeping the engine over the wing in the fuselage, but in this case it would allow the propellers to be on the wings in small, low drag, nacelles. This general configuration was proposed with either tractor or pusher propellers, and either propeller could run left or right hand, whichever the customer preferred. It was considered by Bell with pusher props for a follow‑on to its XFM‑1. McDonnell Aircraft's first aircraft proposal in 1939 was for a long range fighter powered by either an Allison W-3420 or a P&W H-3130 buried in the fuselage and driving two pusher propellers aft of the wing through extension shafts and angle gear drives. Only one W-3420‑7 was built, and it never flew.
The W-3420 combined two V1710s into one engine. Many parts were common between the two engines, although some parts were obviously different. Both of the engines shown below had
two crankshafts rotating in opposite directions, although in some versions of the engine they rotated in the same direction."