R 4360 Wasp Major

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cheeka

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Jul 15, 2016
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30
Location
Morgan Hill, CA
Howdy folks,

I am trying to find out how the crankcase came apart for a wasp major. The crankshaft was a one piece forging and the throws wouldn't clear the main bearing bores. So it looks like the crankcase came apart radially like the petals of a flower and I am trying to find any pics or videos that show how the different sections were assembled.

Thanks!
 

Victor Bravo

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Jul 30, 2014
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7,459
Location
KWHP, Los Angeles CA, USA
Contact the Planes of Fame museum in Chino, CA. They either have current experience or had past experience with these engines, as used on their FG-1 Super Corsair racer.

ALSO you can try Aviation Warehouse in Adelanto, CA. They have the largest collection of aircraft and engine manuals that I know of. Chances are they have a 4360 overhaul manual somewhere.
 

BJC

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Oct 7, 2013
Messages
11,251
Location
97FL, Florida, USA
Grahan White is the go-to man for WW II era piston engines. See R-4360 to learn about the crankcase parting line.

His book, Allied Aircraft Piston Engines of World War II is an easy read for a technical subject. I highly recommend it. Graham was a member of an EAA chapter that I was in. He had a big radial (I don’t recall which one) on a trailer. He moved to an airpark in Florida.


BJC
 
Last edited:

wsimpso1

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Oct 18, 2003
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Location
Saline Michigan
Howdy folks,

I am trying to find out how the crankcase came apart for a wasp major. The crankshaft was a one piece forging and the throws wouldn't clear the main bearing bores. So it looks like the crankcase came apart radially like the petals of a flower and I am trying to find any pics or videos that show how the different sections were assembled.

Thanks!
I too am confused as to assembly. Going through the book section referenced in post 3:
  • The author refers repeatedly to the crankshaft being one piece and the cross section illustrations of the oil flows in the crank do not show parting lines in the crankshaft;
  • Many crankshaft photos shoe the edges of what appear to be splined joints at the main bearings and circles of axially aligned bolts, but found no mention of these in the text. Also, there appear to be large internally wrenched screws in the center of main bearing journals in the line drawings. These all make me thing that the crank was built up;
  • In no place can I see any indications of the cases being split radially - they look like they split only into the axial segments as shown in the photos;
  • Further there are mention of how the main bearings are rings press fit into the cases;
The conflict between assertions of one-piece crankshaft and illustrations showing what is likely built up crankshaft is vexing. Additionally, the assertions of rings being pressed into the cases and a lack of any indication of separating each case does drive one to think that that the crank was builtup as the cases
were added.

I strongly suspect that service manuals for these engines would prove very useful to the author of the original post's purposes.

Billski
 

BJC

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Oct 7, 2013
Messages
11,251
Location
97FL, Florida, USA
Once they had the radial design, stacking on more rows was not that difficult. View attachment 97041
Depending on your point of view, that either is a thing of beauty, or a mechanical nightmare. Or, perhaps, a beautiful monster.

I’ve always been amazed by them; can’t walk by one without spending some time looking at it.


BJC
 
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