Click Click Boom!!!!!

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Goodysnap, May 14, 2020.

  1. Shawn2130

    Shawn2130 Heavy Load Member

    Joined:
    Sep 20, 2015
    Messages:
    894
    Thanks Received:
    1,892
    Location:
    Ontario
    0
    SmallPackage:

    You’re right, I forgot about belt driven cam engines as I don’t use one myself.

    My parents was the last in our family to have a timing belt in their car.

    Thankfully that one never snapped the entire time they owned the car. It was a nice car though. 1992 Dodge Spirit.
     
  2. Shawn2130

    Shawn2130 Heavy Load Member

    Joined:
    Sep 20, 2015
    Messages:
    894
    Thanks Received:
    1,892
    Location:
    Ontario
    0
    AModelCat: I remembered that article about the Cummins camless engine.

    Interesting read.

    What’s next? Solenoid driven pistons? o_O
     
    650cat425 Thanks this.
  3. AModelCat

    AModelCat Road Train Member

    Joined:
    Jul 7, 2015
    Messages:
    29,157
    Thanks Received:
    158,610
    Location:
    Canuckistan
    0
    If you think about it, fluids are virtually incompressible. If you could eliminate the piston rods/bearings in favour of a fluid, that would further reduce the internal friction of an engine. As to how the hell one would do that? Beats me lol.
     
    Shawn2130 and 650cat425 Thank this.
  4. spsauerland

    spsauerland Road Train Member

    Joined:
    May 31, 2010
    Messages:
    4,296
    Thanks Received:
    10,887
    Location:
    West Harrison, In
    0
    magoo68, Shawn2130 and AModelCat Thank this.
  5. AModelCat

    AModelCat Road Train Member

    Joined:
    Jul 7, 2015
    Messages:
    29,157
    Thanks Received:
    158,610
    Location:
    Canuckistan
    0
    Wonder how that'd work with the aftertreatment systems? Probably make less heat.

    I remember GM having oil consumption issues with the displacement on demand in their 5.3L Vortecs. I wonder if that was due to cold cylinders or if they alternated the "dead" holes to keep the cylinders evenly heated?
     
    magoo68, jamespmack, Shawn2130 and 2 others Thank this.
  6. spsauerland

    spsauerland Road Train Member

    Joined:
    May 31, 2010
    Messages:
    4,296
    Thanks Received:
    10,887
    Location:
    West Harrison, In
    0
    I think the idea is put greater demand on activated cylinders to get better combustion to improve emissions in cylinder.
     
    Shawn2130, 650cat425 and AModelCat Thank this.
  7. AModelCat

    AModelCat Road Train Member

    Joined:
    Jul 7, 2015
    Messages:
    29,157
    Thanks Received:
    158,610
    Location:
    Canuckistan
    0
    I guess that makes sense. IIRC high combustion temperatures make more NOx but less particulates. Less demand on the DPF and just convert the NOx in the SCR.
     
    Shawn2130 and 650cat425 Thank this.
  8. Flint1

    Flint1 Road Train Member

    Joined:
    Sep 4, 2019
    Messages:
    1,143
    Thanks Received:
    9,805
    Location:
    Alberta
    0
    The oil consumption issue was 2 issues. The pcv orfice is a tin deflector that is riveted and sealed to the valve cover with a silcone sealer. The sealer would degrade and pcv would allow ingestion of oil.

    The other issue was the oil pump relief valve was part of the oil pan, when it was relieving it sprayed oil all over the bottom of the cylinders. Cure for that was a deflector

    The gm system actually "shut off" the valave train with oil pressure solenoids for each cylinder that shuts down. It was designed to trap an exhaust charge in the cyl. They did have issues when the cyl would reactivate, the sudden temp change would cause the spark plug ceramic to crack.

    The pins that held the lifters engaged would also wear, allowing the lifters to collapse when not intended to..
     
  9. AModelCat

    AModelCat Road Train Member

    Joined:
    Jul 7, 2015
    Messages:
    29,157
    Thanks Received:
    158,610
    Location:
    Canuckistan
    0
    Good to have clarification from a GM tech. Thanks!

    I heard of the oil consumption problem on those engines and opted for the 4.8L being under the impression it was directly related to the DoD system.
     
    Shawn2130 and 650cat425 Thank this.
  10. jamespmack

    jamespmack Road Train Member

    Joined:
    Mar 25, 2014
    Messages:
    19,976
    Thanks Received:
    215,615
    Location:
    OH
    0

    Absolutely, also invites moisture to a closed pvc system and dirtier oil. But hey gained some mpg! Er or kpl?
     
    Shawn2130 and 650cat425 Thank this.