T25 Compression Low

Discussion in 'Mech Tech' started by PSG, Feb 27, 2015.

  1. davidoft

    davidoft Sponsor

    It has hydraulic followers, reset them in the hydraulic setting way, (no gap to begin) then run it to ensure the followers are fully pumped up then set again, turn them until they touch then 1 full turn more , if you don't it will rattle and throw the pushrods off and perhaps bust a follower,
     
  2. davidoft

    davidoft Sponsor

    12 bar = 175 psi !!!
    10 bar = 145psi
    8 bar = 116psi
    4 bar = 58psi

    175 is a bit high, 58is low the other 2 are ok, your looking for around 150psi/10 bar ish

    With those results I would say valves

    Have you set valves before ?
     
  3. PSG

    PSG

    Nope. Is it in the Haynes? Or is it easy to do?
     
  4. As said above - compression test -
    all plugs out
    tester in relevant plug-hole!
    Doesn't matter about the coil your plugs are out!
    Throttle to the floor
    Turn engine over (5 seconds will do)
    Read gauge.
    reset to zero
    next cylinder

    Make sure when you put back together that you get the leads the right way around.

    Incidentally unless your battery is absolutely fubared then this wont drain it excessively as the engine will fly round as theres little resistance.

    Post figures here - await sucking of teeth and an assessment of the results.
    Good luck
     
  5. davidoft

    davidoft Sponsor

    It's in the Haynes

    but its pretty easy

    set timing mark to top dead centre on number one cylinder, double check it on the firing stroke by checking the rotor arm point to number one cylinder,

    when you have everything lined up and youre sure its correct

    set both the inlet and exhaust on number 1 cylinder

    rotate anticlockwise 1/2 a turn

    set both the inlet and exhaust on number 2 cylinder

    rotate anticlockwise 1/2 a turn

    set both the inlet and exhaust on number 3 cylinder

    rotate anticlockwise 1/2 a turn

    set both the inlet and exhaust on number 4 cylinder
     
    Last edited: Feb 27, 2015
  6. PSG

    PSG

    Couldn't find it in the index that's all.
     
  7. davidoft

    davidoft Sponsor

    ahhhh , it may not be in there as it happens as theyre hydraulic
     
  8. davidoft

    davidoft Sponsor

  9. PSG

    PSG

    [​IMG]
     
    davidoft and AndyC like this.
  10. davidoft

    davidoft Sponsor

    that's the kiddy, half a turn anti clockwise on the crank, I go for just touching rather than 2 turns on initial setting it allows for the followers not to be pumped up slack in stuff etc, then it should run, you can run and drive it with them set just touching as they will change a little,

    so set at just touching

    run/drive it for a while an hour maybe

    see how it runs, may be a touch rattly from the followers

    reset the valves with 1.5 turns, this is the considered correct amount

    then it should be sweet.

    if not do another compression test and post the results
     
    zed likes this.
  11. PSG

    PSG

    Right just set the tappets as per the Haynes but with one turn instead of 2. Not able to start it now.
     
  12. PSG

    PSG

    Going to try another turn and see what happens.
     
  13. Zed

    Zed Gradually getting grumpier

    That's not going to help. Did any require major setting? Did all the screws end up in similar positions? It's very easy to turn the engine the wrong way at some point and fook it up. :)
     
  14. PSG

    PSG

    A few felt like they moved a lot. At top dead centre on cylinder 1, the left tappet I can adjust nicely.but the right has play on the end of the push rod so I couldn't adjust that 2 turns if I tried. Can't even get it to touch. Does this mean new pushrods needed or something?
     
  15. Zed

    Zed Gradually getting grumpier

    No, it means you did it wrong which is why it now won't start. Try again, concentrate and take your time, you're always in too much of a rush Phil. ;)
     
  16. Zed

    Zed Gradually getting grumpier

    Follow lead back from No'1 to distributor, turn engine until rotor arm points roughly at it, then turn until the timing mark on pulley is at TDC on the scale. Then follow davidofts instructions above.

    You have got a timing scale behind the fan guard next to the pulley on the crank?
     
  17. PSG

    PSG

    Ok so a turn is a full revolution right? So I start again but I can't get the adjustment right on cylinder 1 as the pushrod is too slack in the hole for it to be adjusted. So for instance if I get the tappet to touch, it's still not touching the pushrod and there is no more thread on the screw to turn so that it does touch. I am impatient you are right @zed which sometimes makes me rush, but I am also frustrated. Feel like I need waders I am in too deep.
     
  18. PSG

    PSG

    [​IMG]
     
  19. PSG

    PSG

    [​IMG]

    That's where I am at with the tappet.
     
  20. Zed

    Zed Gradually getting grumpier

    beg pardon, ct engine, no timing scale
     

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