Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Finding TDC

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BayouBlazer88, Aug 13, 2003.

  1. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    I'm in the process of putting my engine back together and I was about to put in the pushrods and rocker arms when I realized I didnt know if I was at TDC compression or exhaust. And of course I already put on the timing chain cover and harmonic balancer so I can't see the cam sprocket. So is there a way to find TDC (compression) or do I need to pop off the balancer and timing cover to check? Thanks.
     
  2. 8_YOUR_H2

    8_YOUR_H2 1/2 ton status

    Joined:
    Feb 20, 2000
    Posts:
    2,663
    Likes Received:
    0
    Location:
    Iowa
    When the 2 lifters on #1 are both all the way *DOWN* it should be at TDC. Do you have a pointer on the timing chain cover?
     
  3. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    [ QUOTE ]
    Do you have a pointer on the timing chain cover?

    [/ QUOTE ]

    Yes. And why didn't I think of that? Thanks.
     
  4. RustBuket

    RustBuket 1/2 ton status

    Joined:
    Feb 21, 2003
    Posts:
    1,618
    Likes Received:
    0
    Location:
    Saskatchewan, Canada
    The point only half works because the piston could be at TDC of the compression OR exhaust stroke like he mentioned. To find the compression stroke, roll the engine over with a bar with your finger against the #1 spark plug hole. Continue rolling it over until you feel air to start coming out of the hole. At this point, stop and find the timing mark and continuing turning it until it reaches the TDC position thats labeled on your timimg marker. (you are turning it clockwise right?)
     
  5. 8_YOUR_H2

    8_YOUR_H2 1/2 ton status

    Joined:
    Feb 20, 2000
    Posts:
    2,663
    Likes Received:
    0
    Location:
    Iowa
    If the pointer shows TDC and the #1 valves are closed its at TDC. So I guess its 100% accurate if you look at it that way. /forums/images/graemlins/rolleyes.gif
     
  6. BigBadJap

    BigBadJap Registered Member

    Joined:
    May 23, 2003
    Posts:
    76
    Likes Received:
    0
    Location:
    Alberta, Canada
    What I did was rotate the crank to about 45* Before TDC and stuck my finger in the exhaust port of #1 cylinder. If the exhaust valve is open, you are coming around to TDC #6; closed means your coming around to TDC #1. (The whole engine was assembled with the valve covers on so I couldn't physically see the rocker arms move up and down)
     

Share This Page