DoD motors

Discussion in 'High Tech Retrofits' started by ErikNORCAL, Oct 11, 2019.

  1. ErikNORCAL

    ErikNORCAL Veteran Member

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    for the techs and owners that have experience with DoD engines:

    - how long does the DoD part of the engine typically last?

    - what are typical DoD failures and causes?

    Asking because I am running a DoD 5.3 with the DOD oil towers blocked off. Cam swap is a long ways off.

    Thanks
     
  2. djorgensen3

    djorgensen3 Veteran Member

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    Do have a link that shows what you are referring? I have a DOD 5.3 too and that sounds interesting
     
  3. camarochevy1970

    camarochevy1970 Veteran Member

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    the lifters will fail before anything else
     
  4. ErikNORCAL

    ErikNORCAL Veteran Member

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    Djorg - pretty sure there is a picture under the high tech section of when I started unless photobucket is holding it hostage. Basically take off the valley cover and you will see the oil towers on the DoD cylinders.

    Camarochev- that is what I figured but curious if it’s more from use, cycling back and forth - so if they are disabled or “locked” in position, is there a greater chance of them lasting. Either way, how long do they typically last?
     
  5. djorgensen3

    djorgensen3 Veteran Member

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    Thanks for the help. I'll look it up.
     
  6. Knuckle Dragger

    Knuckle Dragger Mayor of Simpleton Staff Member Lifetime Gold Member

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    Really zero point in it unless you're going to change the cam and lifters too. The DoD can be programmed out if you just don't like the deactivation symptoms/feel. The failures that concern most people is lifter failure and catastrophic engine damage that leads to, and unless you remove them it's only a mater of time. The bitch is on the LS platform the heads have to come off to swap the lifters.
     
  7. djorgensen3

    djorgensen3 Veteran Member

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    Thanks for the info dude. I don't have any plans on doing it anyway in my daily driver but the thought is interesting and I figured I'd read up on it.
     
  8. ErikNORCAL

    ErikNORCAL Veteran Member

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    Dave, the heads have to come off if someone was going to do a cam swap? Uuuuggggh.... awesome... more time and effort...

    What are low and high mile range you have seen for failures?
     
  9. tom3

    tom3 Veteran Member

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    We have a new Tahoe and I have been studying this some. The older models do have some failures, lifters and down into the cam I believe. Main problem seems to be the method of killing the same cylinders constantly. Usually a good bit over 100k miles. The newer motors do this on a rotating cylinder basis they say and pretty much eliminates the failures over a much longer life. They say. But the cylinder drop off and turn on is seamless, wouldn't know it without a readout, and MPG sure takes a jump when the V4 symbol shows.
     
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  10. Knuckle Dragger

    Knuckle Dragger Mayor of Simpleton Staff Member Lifetime Gold Member

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    The way I understand it you can use one of two techniques to hold the lifters up and swap the cam conventionally, but for sure the heads come off for lifters. I have seen flat out abused motors with close to 200k and 4,000+ hours with all their original parts. I have also seen GM re-manufactured engines drop a lifter within 2,000 miles. I've sent several 2018s in for lifter failure with less than 50k. I think it's a not to spec parts supplier, but GM big wigs tell my bosses they are looking into it.........for the last 3 years.

    The two techniques I have heard about for cam swaps are (no first hand experience or confirmation):

    A: Pull the rocker arms and rotate the engine and the lifters will stay up in the plastic guides allowing the cam to be pulled and replaced.
    B: I was told there was a passage on each side of the cam to insert a dowel rod to hold the lifters up so the cam can be replaced.

    Google would be your friend to confirm...........
     

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