R975 Radial engines

[Jordan Baker]

Found this while doing some late night CAM reading.

[Hanno Spoelstra]

Originally Posted by Jordan Baker

Found this while doing some late night CAM reading.

Excellent, Ram tank material!

If anyone is wondering what CAM magazine is, see this thread:
http://www.mapleleafup.net/forums/sh...ad.php?t=28361

H.

[Bob Phillips]

Great poster Jordan!
I should send all interested readers, to an excellent WW2 era report on the R975 recently posted on the Sherman Site. It is the most detailed history I have ever read and I only discovered it a few weeks ago. Many interesting bits of information including;
- many failures due to overheatine, hence C4 styled cylinders
- significant issues with excess fuel during shutdown , therefore degassr shutoff valves
- over reving of engines (engine as brake) spells quick death to engine
- as C1 and C4 share 85% same parts many C1s converted to C4s during major overhauls
and much more!
BP

[Bob Phillips]

In a previous post reference was made to the Bill Gregg collection now under the TLC of Rob L. There are some good photos of some of the major items including unrestored condition pics if you search up Bill Gregg photos at the Wellington County Museum and Archives.

[Bob Phillips]

Just a couple of pictures to add to these older posts, an experimental flight with a helicopter using a 975-46 engine and a closer look at the shroud used on a -46 engine.

[Bob Phillips]

I have included some photos of the 975 rear main bearings. I am looking for some expertise from the forum readers if you can help. Both the C1 and C4 engine use very similar bearings- and while I have a large number of misc bearings the only difference I can see is the addition of the large slot/notch on some of these bearings. Can anyone verify whether C1 and C4 bearings ( which have different parts numbers in the manual) are in fact interchangable? You can clearly see a narrow keyway and the larger notch in the photos.

bearing1.jpg bearing2.jpg bearing3.jpg

Just an update... The bearing with both slot and oval notch as shown is for a C1 engine. A bearing with only the slot is for a C4 engine.
A bearing for C1 will apparently fit and work in a C4 engine but a C4, lacking the oval notch, will not work in a C1 engine.

[peter simundson]

Maybe that large slot on the Wright 975 is an increase in the oil gallery size to get more moving through.

Peter S