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Thread: Connecting Rod install on a 6.2

  1. #1
    Join Date
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    Default Connecting Rod install on a 6.2

    In the 6.2 rebuild thread in the 6.2/6.5 tech forum I saw that the connecting rods had a specific orientation. I see why they are supposed to be that way because of the bearing, but is there another reason. Are they not symmetrical? I have read that many engines have connecting rods that aren't symmetrical.

    The reason I ask is because when I built my engine I paid no attention to the connecting rods and probably but some in backwards. I have also had a ticking sound in the engine and I am wondering if it may be caused by installing connecting rods backwards. I guess it does not matter because my block is cracked, but if I could at least stop the ticking I would feel much better.

    Thanks,
    Kyle
    '83 Blazer, DB2 built like 4911 by Accurate Diesel, 6.5 oil pump, 6.5 turbo injectors, 82 6.2 block, 6.5 heads, serpentine, gm-4 turbo with turbo master, timing gears, custom stud girdle, lower compression
    Pics: http://s153.photobucket.com/albums/s205/kkarlson_photo/

  2. #2
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    Default

    You'd have to completley take the engine apart to resolve the issue if you have one.

    I think they're close to symectrical, but I have no proof to back that up, just eyeballing them. They need finished ends on the big end in order to slide beside one another on the journal, reversing this will cause wear.

    I don't know about a noise, but it's possible.

    I always keep a rod and piston combined hanging on the wall as a reference when putting together pistons and rods so there isn't a doubt on the orientation.

  3. #3
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    Default

    The distance between the big end bearing and piston pin bushing is the same either way you install it, so the only issues would be with interference with other parts. If the rod hit something it would probably be over quickly, although this could be the source of the noise if it's really light contact.
    The Constitution needs to be re-read, not re-written!

    If you can't handle Dr. Seuss, how will you handle real life?

    Current oil burners: MB GLK250 BlueTEC, John Deere X758
    New ride: MB GLS450 - most stately
    Gone but not forgotten: '87 F350 7.3, '93 C2500 6.5, '95 K2500 6.5, '06 K2500HD 6.6, '90 MB 350SDL, Kubota 7510

  4. #4
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    Apr 2005
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    Default

    Thanks for the replies. I will probably fix the rods if there are any backwards and see if it stops the ticking just for the sake of knowing what was causing the sound.

    Yeah, I know I would have to tear it down all the way to fix it. I cannot really do it anytime soon but the car is in storage now while I am in school and I only drive it occasionally when I am home. However, I still will probably tear it down in a few years. The tick has driven me crazy for a long time and I would love to figure it out.

    -Kyle
    '83 Blazer, DB2 built like 4911 by Accurate Diesel, 6.5 oil pump, 6.5 turbo injectors, 82 6.2 block, 6.5 heads, serpentine, gm-4 turbo with turbo master, timing gears, custom stud girdle, lower compression
    Pics: http://s153.photobucket.com/albums/s205/kkarlson_photo/

  5. #5
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    Member rogers has posted what to look for when assembling an engine in regard to the connecting rod's orientation.

    http://www.thedieselpageforums.com/t...8&postcount=31

    Basically, the rod only differs on the large end of the rod, in the bearing spacing. No sense in having the bearing cover the rolled fillet. Also, if the rod is installed backwards the bearing's surface area is reduced.

    I didn't actually look closely as to the "why" it was orientated the way it was when assembling past engines, just did it "because" it was assembled that way originally. You know, assembly in reverse order as removal, exactly.

    Just thought I'd share because the information above in Roger's post is invaluable, helps to properly identify correct connecting rod orientation when it's installed.
    Last edited by john8662; 11-16-2009 at 21:45. Reason: Edited link to reflect post, and fixed my errors in sentence content due to hangover...

  6. #6
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    So the bearing shell is offset side to side (fore and aft)? Interesting!

    I could not identify the post to which you referred. What post number is it? Page numbers are not necessarily consistent form one member's view to another....

    (Never mind, I found it. It's post #31, page 3 for me...)
    The Constitution needs to be re-read, not re-written!

    If you can't handle Dr. Seuss, how will you handle real life?

    Current oil burners: MB GLK250 BlueTEC, John Deere X758
    New ride: MB GLS450 - most stately
    Gone but not forgotten: '87 F350 7.3, '93 C2500 6.5, '95 K2500 6.5, '06 K2500HD 6.6, '90 MB 350SDL, Kubota 7510

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