intake valve length

Discussion in 'PSI Superchargers Tech Questions' started by Dragsterbus, Jun 13, 2009.

  1. Dragsterbus

    Dragsterbus Member

    Joined:
    Oct 9, 2008
    Messages:
    141
    Likes Received:
    0
    Hi, speaking to lots of people their intake valves seem to be 5.6" long, I've set my valves up for optimum positioning of the rocker (and set with the adjuster out two threads ) and mine work out at 5.55 INCLUDING lash cap, this is with 1996 Dart twin plug heads, the valve seats don't seem to be set into the head (the lip of the valve is just proud of the head face) if i set it up at 5.6 the roller of the rocker is almost on the corner of the lash cap which will rock it on the valve and will make it likely to flick up, I know i can get the valves cut to any length so it's not a problem, just wondered if anyone else has this set up, the rockers are Dick Landy from what i can gather,the valves are 2.375 "
    Cheers
    Wayne
     
    #1
  2. cd3d

    cd3d New Member

    Joined:
    Mar 29, 2007
    Messages:
    33
    Likes Received:
    0
    valves

    wayne, you are right that the geo is better w/ shorter valve. you may not have enough room for a good spring with the shorter valve. this is why most newer rocker stands raise the shaft to improve the situation. what stands do you have? chuck
     
    #2
  3. Dragsterbus

    Dragsterbus Member

    Joined:
    Oct 9, 2008
    Messages:
    141
    Likes Received:
    0
    Hi Chuck , I guessing the stands are Dick Landy like the rockers, they are anodised blue , since i posted this i've been playing around with different valve lengths and i've got it as good as it's going to get and there's still just over 2" of height for the valve springs. The rockers seem to be in very good shape and hopefully they will be good enough for what i'm doing, maybe next year i'll upgrade to some newer heads and rockers ( better start doing the lottery again)
    Thanks for the reply Chuck
    Wayne
     
    #3
  4. cd3d

    cd3d New Member

    Joined:
    Mar 29, 2007
    Messages:
    33
    Likes Received:
    0
    geo

    blimey wayne, 2" is just enough. i have sometimes run 1.950 but depends on springs. take a spring & retainer and put it in a vise, compress until reaching compressed length. make sure there is some room left between coils. landy intake (1.6 ratio) times lobe lift (.475-.500) minus lash .025 will give you full lift at valve.
    remember to check guides with retainer, locks and valves for room left between bottom of retainer and top of guide. i have sometimes shortened top of guide to get clearance. i.e. if lift is .800, you want .850 min. stem showing between guide and retainer. don't shorten guide unless you have too, it will wear out faster. as winston said, "we have nothing to fear but fear it self" chuck
     
    #4
  5. Dragsterbus

    Dragsterbus Member

    Joined:
    Oct 9, 2008
    Messages:
    141
    Likes Received:
    0
    Hi Chuck, Thanks for the info , I'll check everything and measure everything twice , I've been building cars for nearly 27 years but this is my first blown hemi, everydays a learning day !
    Thanks again
    Wayne:D
     
    #5

Share This Page