Any 2-stroke gurus in here? Detroit 8v71 with misfire need help

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Green461, Nov 10, 2022.

  1. AModelCat

    AModelCat Road Train Member

    27,741
    145,376
    Jul 7, 2015
    Canuckistan
    0
    Sounds to me a lot like an exhaust leak. I do like the idea @jamespmack had about checking cam lift.
     
    jamespmack and lilillill Thank this.
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. lilillill

    lilillill Sarcasm... it's not just for breakfast

    5,642
    13,468
    Nov 7, 2007
    Possum Booger, Alabama
    0
    I did listen to the video again and it does sound like an exhaust leak. The only thing that doesn't make sense is the cold temperatures of the exhaust on that cylinder.

    If it has enough power and seems to run good going down the road, I'd pull both mufflers and see if it still sounds like it's missing.
     
  4. OLDSKOOLERnWV

    OLDSKOOLERnWV Captain Redbeard

    16,599
    246,160
    Nov 29, 2011
    West Virginia
    0

    If you’re speaking of this picture, that’s my 92 series in my General….

    370D6EBD-F545-47E1-857E-76B582C6AA37.png
     
  5. Inderjit

    Inderjit Medium Load Member

    626
    609
    Sep 17, 2017
    0
    Yes that is the picture.
     
    OLDSKOOLERnWV Thanks this.
  6. Green461

    Green461 Light Load Member

    127
    75
    Mar 22, 2019
    Southern WI
    0
    Was told by previous owner it was 8v92 but it has 71 on the breather on valve cover, water pump ID from somewhere I read looks like 71, and it had N65 injectors in it. Injector height were all close to 1.484 from series 71 spec sheet I found for those injectors. I assumed it was a 71.

    Didnt get over there today. Also found on the other side that does not make the noise is a cracked exhaust manifold, good 1.5 inch long and 1/8" wide by ear. Puffs smoke out of crack while cranking but I think its creating a vacuum while running and adding extra air ... guessing could smooth it out and not make it as percussive?? along with the larger muffler...
     
  7. Inderjit

    Inderjit Medium Load Member

    626
    609
    Sep 17, 2017
    0
    If you look at the airbox covers on the side of the block the 92 series are cast aluminium the 71 series are stamped steel and their larger. Post some pictures and I can tell you.
     
    BoxCarKidd and lilillill Thank this.
  8. OLDSKOOLERnWV

    OLDSKOOLERnWV Captain Redbeard

    16,599
    246,160
    Nov 29, 2011
    West Virginia
    0

    Valve covers will interchange between the 71 & 92. The 53 series is a different animal with hold down screws around the outside edge like a older Chevy or Ford….
     
    jamespmack and lilillill Thank this.
  9. Green461

    Green461 Light Load Member

    127
    75
    Mar 22, 2019
    Southern WI
    0
    IMG_6807.jpg IMG_6814.jpg
     
  10. OLDSKOOLERnWV

    OLDSKOOLERnWV Captain Redbeard

    16,599
    246,160
    Nov 29, 2011
    West Virginia
    0
    lilillill and jamespmack Thank this.
  11. OLDSKOOLERnWV

    OLDSKOOLERnWV Captain Redbeard

    16,599
    246,160
    Nov 29, 2011
    West Virginia
    0
    This is a 8V92 block….. FEBEE823-E52C-4C6D-8C44-354BFEF781C1.jpeg
     
    BoxCarKidd, lilillill and jamespmack Thank this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.