Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon
I made two very bad photos of port and starboard linkdifferences for the servo/fuelrack linkages just to show you what to look for.
Tore

[tore]

Simon.
I am not sure if your two overhead drawings of the fuelpump/fuelrack is representing port and starboard engine. In case it is, starboard engine pumps are different connected, they are turned 180 degrees  This results that the movement of the fuelrack linkage is opposite that of port engine resulting a different endconnection to the servomotor and fuelhandle. I have indicated below what I try to explain.
Tore

 Hi Tore
 
That was a little trickily!! It took me a little bit of time to work that out. It was not a simple 180

Simon, I wonder why you have displaced the HP fuelpumps on stb engine  in relation to the port. Basically the centerline for the cylinders are the same and placed right opposite to  each engine. So each fuelpump is directly on the same spot on port and stb engine. The change of the fuelrack between cylinder 3 and 4 is simply a production necessity. The two engineblocks are just  flanged  together right here. The flange make it necessary to move the fuelrack pedestal to another position, hence the fuelrack coupling for cyl. 4 and 5. Se my pictures.
Tore

[NZSnowman]

Hi Tore

When I started updating the starboard fuel pumps the other day, it seen worng. So I take a second look at the starboard engine using Kubische Panoramen, and noted the offset of the fuel pumps. From the photo below you can see the offset of the fuel pumps.

Port fuel pump is forward of the rod & starboard fuel pump is aft of the rod.

[tore]

Simon I had the same impression but from an enginering point I couldnt`t believe what I saw. After checking I have come to the conclusion it must be an optical illusion. I cannot se any reason for such an arrangement which would involved another camshaft or place the stb engine a bit forward of the port. I am almost 100% sure the cylindercenterlines on both engines are in line.

[NZSnowman]

Tore, I believe you right the cylinder are center lines, but I believe the fuel pumps are offset for so unknown reasons.

If you look at two rods (number 5 & 6 - Marked on the photo), the port fuel pump is right next to no. 5 rod. On the starboard side the fuel pump is right next to no. 6 rod. You can see the gap I have mark on the photo.

[tore]

Tore, I believe you right the cylinder are center lines, but I believe the fuel pumps are offset for so unknown reasons.

If you look at two rods (number 5 & 6 - Marked on the photo), the port fuel pump is right next to no. 5 rod. On the starboard side the fuel pump is right next to no. 6 rod. You can see the gap I have mark on the photo.

Simon I think I have found an explanation. The cylinder centerlines are matching on port and stb engine , the are not displaced in relation to each other. The camshaft is the same on both engines but turned 180 degrees on stb in relation to port, this can be done because port and stb engine have opposite revs direction. The registerdrive have to be fitted on the otherside of the stb camshaft though.  The cylindercovers and crankshaft are turned 180 degrees as well which means the the valves ( except the center placed fuel injectionvalve) change place so on stb the exhaustvalves are forward and on port aft. The startingvalves are forward on stb and aft on port engine.This fit excellent with the camshaft. On the crankshaft the registerdrive ,and vibrationdamper have change place.This is a much cheaper way of building mirror execution engines. On you drawing the visualeffects would be positions of the startingvalves with rods, exhaustvalves with cooling waterpipes , thermometers and lubricatorpipes, inletvalves with lubricatorpipes. if you look at the Kubische Panoramen picture you can clearly see this. On starboard engine the rod for the startingvalve is forward of the HP fuelpump, on port aft. If you check on the top you no doubt would see the different places of the inlet and exhaustvalves.
Tore

[tore]

As an additional information you will see the indicator cocks are aft of the HP fuelpumps on port engine and fwd on the starboard. This means that the HP fuelpumps are placed in the centerline as the fuelinjetorvalves are, so I believe no displacement for these items.
Tore

[NZSnowman]

Hi Tore

Thanks for the information. But it did show my short coming in machinery knowledge I follow must of it, but a bit was over my head

Below, I did a very basic overhead layout on what I understood from the last posts, does this seen correct? Starting to get a little confuse

[tore]

Simon
Sorry sometimes I get carried away. The main thing is that you get the visual facts so your pictures are as correct as possible. It is always  a reason for things are like they are and sometimes when you understand the reason it is easier (for me at least) to get things correct.
Tore

[NZSnowman]

Hi Tore

No worry, I always like lots of information!

I had again look and I noted the exhaust (dark blue) is forward on each cylinder head, not like my previous drawing.

[NZSnowman]

Hi Tore

As I have no photo's of the starting valve system, it extremely hard to get a accurate drawing, so I am drawing the cross-section to help me in the other views. How does this look below? I am still adding detail to the drawing.
 
Thanks, Simon.

[tore]

Simon not bad. The rocker arm, indicated in black, goes to the other side of the fulcrum, just like the exhaust/inletvalve rocker arms. The valve rockerarms engages the valvespindle in a slot. I am in doubt about the valve you have placed on the control airpipe to the top of the valve, do you have a picture of that? Below on my picture I have tried to explain a bit more on the details.
Tore

[tore]

Simon judging from your last posted picture I got the impression that my post yesterday was a bit confusing. I`m posting your photo where I have indicated what I mean to say.
Tore

[NZSnowman]

I am in doubt about the valve you have placed on the control airpipe to the top of the valve, do you have a picture of that?

(source: U-995 DVD http://www.uboataces.com/u995.shtml)

[tore]

Simon
I guess it is OK!
Tore