Hydralic valve clearance ?

Unknown
Unknown
edited November -1 in HUDSON
We are working on a 1956 308, it has had all seats ground equal depthwise. Cooper supplied new valves,when trial assembled valves are off seats when they should closed, using stock hydrolic lifters. How do we determine the proper length? I know we will have to have end of valve stem shortened by machine shop. Thank for the help Lou Cote

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  • Unknown
    Unknown
    Ken, you must have been tired, lifters had been allowed to leak down. I may have not given enough info. Four seats were replaced, and all seats were ground to same depth . As engine has had previous valve jobs, How do we determine correct lenth of valves? Do end of stems need to be shortened? Hudsonly Lou Cote
  • Unknown
    Unknown
    Ken

    Thanks for the info and you are correct. The engine has had at least two valve jobs in the past, and as Lou indicated, four new seats were installed and set at the same deapth as the reground seats............so our baseline seat height is approx. .060 - .080 lower than orginal. That along with Dale Coopers "new" Bi-metal valves, which are a bit longer than the OE, the valve stems need to be shortened (.100 inch) to insure the .040 to .080 clearance between the valve stem and the top of the lifter is achieved with the valves fully seated (closed) and the correctly serviced and bottomed lifter is all the way down (on heal of cam). If any of you have an old Motor's manual that covers 1956 Hudson or 1936 thru 1948 Cadillac & La Salle V8 you can see the service proccdure first hand.

    Happy Hudsoning
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