P&W R-4360 Wasp Major

[Birdog357]

I was reading about the XB-35 and it mentioned that the wing used two different marks(R-4360-17 and R-4360-21) of Wasp Major engines so me, being me, had to find out why. Along the way I discovered this awesome paper discussing the development of the ultimate expression of airborne piston engines. It came from here with this copyright notice on the main page. Enjoy.

3. The Piston Engine Revolution

Although these papers, from the conference of the same name, are published in book form, the conference organisers decided that they should be made available without let or hinderance. If you do decide to make use of the papers, please acknowledge the time and money that was spent by the conference organisers, Bryan Lawton, Ed Marshall, John Anning and Fred Starr in setting up the conference and getting the conference volume published.

BTW, the answer I was looking for: The inboard engines had longer output shafts necessitating a different sub type.


Edit: changed -21 from -19

 

[Birdog357]

Another excellent resource from http://www.enginehistory.org/Piston/P&W/R-4360/r-4360.shtml

 

[Foo Fighter]

Thank you, Sir. Neat paper.

 

[Birdog357]

Thank you, Sir. Neat paper.

It is. Stumbled across it and had to bring it here to share.

 

[Pasoleati]

What is the title of the book form mentioned in the first post and where can it be bought from?

 

[Birdog357]

What is the title of the book form mentioned in the first post and where can it be bought from?

A little bit of Google yields this: https://www.newcomen.com/shop/books/the-piston-engine-revolution/

 

[Dagger]

I was reading about the XB-35 and it mentioned that the wing used two different marks (R-4360-17 and R-4360-19) of Wasp Major engines .........

For the XB-35 with counter-rotating props, the two outboard engines were R-4360-17
and the two inboard engines were R-4360-21 (not -19).

After replacing the counter-rotating props with single props, the two outboard engines were redesignated R-4360-45
and the two inboard engines were redesignated R-4360-47.

 

[Birdog357]

I was reading about the XB-35 and it mentioned that the wing used two different marks (R-4360-17 and R-4360-19) of Wasp Major engines .........

For the XB-35 with counter-rotating props, the two outboard engines were R-4360-17
and the two inboard engines were R-4360-21 (not -19).

After replacing the counter-rotating props with single props, the two outboard engines were redesignated R-4360-45
and the two inboard engines were redesignated R-4360-47.

Correct, I mistyped. I didn't want to confuse the issue by bringing up the subsequent change since the only difference between inboard and outboard is shaft length and that remains true for the standard props too.

 

[YouCantbeCirrus]

What a cool paper and a very nice resource, I only perused the source website but man it seems like my kind of place. And some of those illustrations are pure engine nerd's wet dream.
I love the Wasp Major and some of the other very late stage radial engines but man it's no wonder even those early jet turbines where still preferred over those horrendously complex beasts.
As a maintenance tech kinda early in his career I'd hate to be an apprentice back then-having to change ALL of those sparkplugs and rotate them for wear must've been a nightmare!