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Old cummins compresion release mounting

Discussion in 'Trucks' started by workshoprat92, Sep 10, 2018.

  1. workshoprat92

    workshoprat92 Senior Member

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    I gave this compression release set up to someone that I had taken off an engine. I cant remember how it mounts on tje engine. Anyone know or have a picture. Here is what im thinking is this right?

    received_2134939116758480.jpeg
     
  2. Truck Shop

    Truck Shop Senior Member

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    Should be horizontal mount- your missing some parts I believe. The only place I ever saw one that looked like that one was under the hood or cab of a Corn Squeezer. Does the engine it's going in have the lift
    rail in the block? Plus you will need the correct push tubes with flange.

    Truck Shop
     
    Last edited: Sep 11, 2018
  3. Tenwheeler

    Tenwheeler Senior Member

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    I thank the top of the red arm goes closer to the center of the engine. Looks like one is already bolted to the engine behind the red one. The L shaped arm at the bottom needs to be turned about 90 degrees clockwise.
     
  4. kshansen

    kshansen Senior Member

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    Actually I think that might be right. It appears there is a lever on the engine and if you replaced that one with the orange one and then mounted the angle bracket to the two outside bolts for the compressor/fuel pump drive it should work.

    As I recall the lever for the compression release is not keyed to the shaft, seem to recall there being a dowel pin sticking out the front of the block that limited the stroke and a slot in the end of the shaft to let you adjust it in the lever. Have an old NH book that briefly shows and mentions the compression release but I can not see any adjustment procedure for it.

    For lack of any spec's on adjusting it I would install the arm loose with the "return spring" holding it to the left as you face front of the engine and after setting all valves turn shaft clockwise till you feel it touch the collars on the push rods then turn back counter clockwise a touch for clearance, again this is looking at the engine from the front.

    The release only opens the valves a very slight amount just enough to bleed off compression to let engine turn over easy.

    If you look at the back side of the lever you might see marks from the dowel pin that should be a little.

    Picture below has red arrow pointing at the dowel pin mentioned above and shows the slot in the end of the shaft, green arrow. NH22005.jpg
     
  5. Truck Shop

    Truck Shop Senior Member

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    Here are some pics, in the first one it has a compression release like yours and that engine came from a International. The other two are standard Cummins.
    These old girls were proud to raise their skirts for photos.

    Truck Shop

    001.JPG 003.JPG 005.JPG 004.JPG
     
    GregsHD likes this.
  6. Truck Shop

    Truck Shop Senior Member

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    More photos 006.JPG 008.JPG 007.JPG
     
  7. kshansen

    kshansen Senior Member

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    Some clever designs on some of those releases!
     
  8. workshoprat92

    workshoprat92 Senior Member

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    I did find a picture that shows how this one mounts. TandemEngineHeads.jpg
     
  9. kshansen

    kshansen Senior Member

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    Looks like the cable hold down is mounted to a bracket on the fuel pump.

    I was thinking the bell-crank bracket went to the bolts holding the accessory drive to the front cover but it now looks like it is mounted with the bolts that hold the compressor to the accessory drive. Does look like that would give better geometry to the linkage.
     
  10. Truck Shop

    Truck Shop Senior Member

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    What's even better it's a International.

    Truck Shop
     
  11. workshoprat92

    workshoprat92 Senior Member

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    Yea i think your right! I had an old 74 4300 i just loved! I was gona get another one till i figured out i no longer fit in em. Not enough room between the steering wheel and back of cab!
     
  12. kshansen

    kshansen Senior Member

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    Something about the cabs on those old trucks, they seem to shrink as the steel drys out over the years! Maybe you could spry down with some WD-40 to prevent the shrinkage, sort of like how you treat old leather!
     
  13. workshoprat92

    workshoprat92 Senior Member

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    This sounds kind of like how my wife likes to point out that its not my shirts shrinking in the washer lol!
     
    Theweldor likes this.
  14. kshansen

    kshansen Senior Member

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    :p