6.5 Identity questions? Help please

[jeffclark42]

I have a 6.5l turbo quasi-long block that I got through a friend. I believe, that the block came from a Hummer, but I'm not sure. Also, I believe the block suffered from a bad head gasket, but again I'm not sure. I have 2 questions.

From reading the Diesel page forum (and other sites) I have determined that I have a 506 block with a date code of H080 (August 8, 2000) which I believe puts it in the improved GM block category but not an AMG Navistar block.

I have checked the "mainous" site photos and have found the following:

- my block matches the OLD BLOCK VALLEY photo
- my block matches the NEW BLOCK (DR. SIDE) photo
- my block matches the NEW BLOCK (PASS SIDE)
- my block matches the OLD VIEW OF PISTON SPRAY TUBE photo

1) What can I assume based on these photos about my block and any enhancements?

For the purpose of disassembly / assembly, I have been using an AM General Hummer 2000 parts and service manual. My block seems to differ from the illustration and parts listings in that there is a "depression" in the valley underneath where the turbo would mount. This depression is connected to a metal tube which routes just inside the bell housing and exits the engine just above the oil filter adapter.

2) What is this tube and depression? Water / oil drainage for the valley?

Thanks for any help!

Jeff

[john8662]

The tube is for drainage of fluids that might collect in the valley of the engine.

Usually when changing an injection pump, you will lose a little diesel fuel which will run down the valley of the engine and then exit through a hole drilled in the block. From there the fuel, or water or whatever drains directly on or near the rear main seal and then into the transmission inspetion cover (which has a hole for drainage as well).

The tube is a "newer" idea to keep things a little cleaner, although not necessary at all.

So, which 506 do you have, the one for the Hummer Turbo or out of a N/A truck that was a replacement engine of some kind?

[jeffclark42]

Thanks for clearing up the tube question. I had a feeling it was a drainage thing but wanted to be certain.

As for the block, all I can tell is that it is a 506 casting made in late 2000. With the exception of larger diameter piston spray tubes, it appears to match the current AMG Navistar casting.

I got the engine from a Hummer dealership, so I'm guessing it came from a Hummer...though there is a GM/GMC service department adjacent, so I suppose it could have come from a GM/GMC van (valley mounted turbo).

My main interest is in how "enhanced" the block is.

Jeff