Looking for a Radial Air Cooled Engine.

[CaptianNemo2001]

I have an airborne tank on file with louvers at the rear for 1942. USA.

But my problem is I need a radial air cooled engine that will fit in a space no wider then 37.5 inches in dia.

The louvers up on the rear deck, side on, are aprox 17 inches long. But there is a lot of space (hull length) for a radial or even a duplex.
I have looked at the T-1020 and thats too big... but haven't found the W-670/R-950 diameter yet.

As much as I love engines, I keep getting the feeling lately that if I want X... I really should just write the book.
Most of the engine books out there list things like HP or bore/stroke and tend to ignore the LWH.

Been looking for anything circa 1932 through 1942 that could be found in the US.
Sadly my engine books are all in boxes atm.

If you guys have any ideas... I'd love to hear them.

 

[kmccut]

...

Been looking for anything circa 1932 through 1942 that could be found in the US.
Sadly my engine books are all in boxes atm.

If you guys have any ideas... I'd love to hear them.

Check here
https://www.enginehistory.org/References/ModDesig/moddesig.shtml

 

[jstar]

The Jacobs L-4 series, to include the R-755, has a diameter of 43.5 inches. Still looking for smaller.

What's the tank? Actual? Or something else?

Interesting related read here: https://ww2aircraft.net/forum/threads/why-were-all-radial-engines-about-the-same-width.46897/

 

[CaptianNemo2001]

The Tank is a design by the US Army G3 Section in 1942 for an airborne tank of their own design using Christie suspension. Sadly it looks a lot like Christie's designs and has its own flaws. Its for an article on Tanks Encyclopedia.

I suppose in retrospect the bump could be part of a radial at the back.. It just seems odd.It also seems unlikely given what I know of tank plans and engine placement.

 

[jstar]

Looks more like a Tank Destroyer or Assault Gun (no turret I can see), and I would think maybe because of the hull length behind the fighting compartment, there's an inline. The hump on the back slope could cover the header tank on a water radiator. And if the hump is over a radial, with a rear mounted drive sprocket, where do you put the transmission?
My two cents.

 

[riggerrob]

For a while, you had me wondering if it was a Marmon-Harrington M22 Locust light tank powered by a Lycoming O-435-T, six-cylinder, horizontally-opposed engine. Since the Lycoming was air-cooled, it still needed cooling louvers on the rear deck. Only a handful of Locusts were supplied to the British during WE2.
The Lycoming O-435 engine was more widely used in first-generation Bell 47 Helicopters.