Questions reg. Bristol Hercules VI, X, XVI engines

[ChrisMAg2]

Question for our engine experts:
I am discussing the type of a crashed britsch bomber on two german forums.
We have come to the point that we would need experts on Bristol (Hercules Vi, X, XVI) radial engines. We urgentely need to know:
-What are the differnces on the different versions?
-Is the propeller hub a mean to distinguish them?
-How do the differnt hubs look like?
-What kind of propeller was used (wood or metal blades)?
-In what kind of aircraft were the different engines used?

FYI: the crash this is all about has revealed four radial engines. One of our members has meant to see and identify a Rotol hub and I seem to see a remains of a wood propeller. This would mean the engine is a Mk VI? But we would need an expert to verify the sights.
The first identification said this was a Lancaster II. Then it was said the engine is a Bristol Hercules Mk VI with Rotol hub and wooden props. But in this combination it cannot be a Lancaster II because the reported crashes do not mention a LII with Mk VI engines. But if we dont have a LancasterII, what do we have then?
Unfortunaley we don't have much more then the engines. The date of crash seems to be for sure Jan. 14/15, 1944 in the area east of Brunswick (Braunschweig), Germany. The remaines are just a buntch of rubbel. We do not have a verification of found serial numbers (yet).

An important question is also: Are these remains Bristol Hercules Mk whatever at all?

You can see some of the pictures here:
http://www.luftarchiv.de/bullet-boar...r=asc&start=15

[Alex Smart]

Hi,

Brunswick Raids were for this period

27/28 Sept 43, one Lancaster Mk III lost, LM345 "LQ-L" of 405 Sqdn.

14/15th January 44, 38 Lancasters were lost, eight of them Mk II.
They were -
115 Sqdn DS720 "KO-D"
115 Sqdn LL673 "KO-G"
408 Sqdn DS767 "EQ-Q"
408 Sqdn LL699 "EQ-C"
432 Sqdn DS740 "QO-Z"
432 Sqdn DS850 "QO-M"
514 Sqdn LL679 "JI-J2"
514 Sqdn LL685 "JI-G2"

Apart from Mosquito raids the next Brunswick Raid was on 22/23rd April 44.

Four Lancasters were lost , two Mk I and two Mk III.

Refs Chorley's BCL 4 & 5
Middlebrook & Everitt's BCWD.

Note: Rotation of Propellors is also perhaps a guide, Left.
Could find no link to Halifax or Sterling a/c which both used the same motors as did the later Wellington.

Hurcules XI, VI, and XVI.
Bore and Stroke the same = 5 3/4 in x 6 1/2in
Dia the same = 52 in
14 cylinders two row

Bristol's had nine single row

BMW's were right handed, except the 801 .
14 cylinder two row
Bore and Stroke = 6.15 in x 6.15 in
Dia = 1290mm (51 in)

Thats it for now.

Good luck

Alex

[Alex Smart]

just an additional bit,


Fortress's had Wright 9 cylinder motors.
Bore & Stroke = 6.125 in x 6.875 in
Liberators had Pratt & Whitney 14 cylinder motors
Bore & Stroke = 5 1/2 in x 5 1/2 in

Re: Pistons

Hurcules
Flat crown
Short skirt
2 compression rings
2 scraper rings one above and one below the gudgeon pin
Gudgeon pin retained by circlips

BMW
Flat crown recessed to clear valves
3 compression rings
1 channelled ring above gudgeon pin
1 bevelled scraper below gudgeon pin
Gudgeon pin, hollow retained by floating keeper rings held in by circlips

Wright
3 compression rings
3 oil control rings
Bottom ring inverted

Pratt & Whitney
3 compression rings
1 scraper ring
1 oil control ring

hope it all helps

Alex

[Graham Boak]

As the Hercules was a sleeve valve whereas all the others were poppet valves, I suspect this would be more readily noticed. However, I can't distinguish between the three variants: I suspect this would be in the gearbox and finer details ather than what can be sen from the photos. Have copies been sent to RR at Bristol for possibly better informed help?