R975 Radial engines

[Hanno Spoelstra]

Originally Posted by Dennis Cardy

Bob and David. Here's 246 airborne with 245...Two of only three RCN HUP-3's that Canada bought in the Spring of 1954. Piasecki only built 30 of the HUP-3's. So a pretty rare version. Note only 246 carries Labrador's sort of...kind of ..SeaHorse crest. It would seem from these photo's, that the R-975's were not that reliable. Not exactly sure when or where these photo's were taken. But can only have been a month or two into the voyage. BTW..Good notes about the cooling fan being charged over. The cooling fan has direct implications for AFV installations.

Spotted last December: UH-25B (HUP-2) C/n 253, BuNo 130076. Location: Baris Business Park roadway roundabout in Rotterdam, The Netherlands. This aircraft was originally used by the US Navy and was later transferred to the French Navy. It is owned by Baris since 1973.

(I can post this here - a HUP is a HUP, eh? )

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Because of the drive-by nature of my own photo I added some more NMPs for clarity.

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[Bob Phillips]

I think you make a good point Peter, clearly the large channel around the bearing exterior is an oil channel ( you can see the small holes leading to the interior) so sticking a notch which presumably holds something must restrict or enhance oil flow?? don;t know but at some point will pull a bearing out of a battered crankcase to see.
Hanno, in my book a HUP is a HUP and more importantly in this day and age they have both survived the scrap man! Thanks for the post!
B.P.

[Bob Phillips]

To follow up my last post on rear main bearings I offer a photo of the -46 version, as I have done for most of the other main parts. Note the much heavier flange area. For those not familiar with workings of these engines, the bearing flange sits flush in the crankcase but the projecting threaded portion supports the camshaft.
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On another topic, a couple of photos of nine mystery boxes, dug out of storage after almost 70 years...what could they be??
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All export packed in waxed cheesecloth over heavy cardboard cartons...
very nice indeed!
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[Bob Phillips]

A beautiful sight for a Sherman enthusiast!

[Malcolm Towrie]

A beautiful sight, indeed! The military packing used back in the day was incredibly good quality.

We had a couple of visitors come by the museum from BAIV, a military restoration company in the Netherlands. When they saw our wrecked Sexton R975 on display, they said the cylinders are going for around 2000 euros each now! So good find.
Malcolm

[Bob Phillips]

Malcolm, your appreciation is very much appreciated! Also a very unique smell as they were packed with thick heavy grease inside and outside.
I want to share a few pictures with you, reminiscent of those showing your beat up Sexton engine. This was a motor I tore apart, it looked great on the outside but not so great inside. You can see half a fractured link rod that was laying inside the motor, the piston was smashed to bits, I took out a couple of handfuls of aluminium chunks and look at the smashed up crankcase and the hole/slot cut right through the cylinder base as the rod came out! I suspect this was hydro static lock up induced, as it was a bottom cylinder right beside the oil sump. Must have been noisy for a few minutes as it disintegrated!
B.P.
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[Malcolm Towrie]

That carnage looks horribly familiar!

Amazingly, our crankcase looked intact though dye penetrant may have shown some cracks.

And that bell-mouthing of the lower liners as the rods thrash around makes it very difficult to pull the cylinders.

Malcolm