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Thread: Cams

  1. #1
    Join Date
    Apr 2019
    Posts
    27

    Default Cams

    Fellow pan heads.
    Whats all your opinions for what is best cam to run, for a stock 48EL?

  2. #2

    Default

    The one you have, unless there's something wrong with it.

  3. #3
    Join Date
    Jun 2005
    Location
    Northern Colorado
    Posts
    840

    Default

    The Andrews J cam works well in Panheads.
    VPH-D

  4. #4
    Join Date
    Oct 2016
    Posts
    131

    Default

    Stock work well for me, I have few if you are in need.

  5. #5
    Join Date
    Apr 2019
    Posts
    27

    Default

    Thanks 620, I have a "J" that I ran in my knuckle, so will try that.

  6. #6

    Default

    I have a "J" that I ran in my knuckle
    Yes, it fits, more or less, since the tooth count and journal sizes match.
    However, the "clock" positions of the lobes are very different than the panhead (and shovelhead) cam. Every open and close point for each valve is not what it's supposed to be, which is what happens when the tappet blocks do not match the cam type for that engine. A knucklehead engine with panhead cam and panhead tappet blocks (or a panhead engine with knucklehead cam and knucklehead tappet blocks) will have the correct (as intended by H-D or the manufacturer) cam events, but the pushrod angles are screwed up. In addition, the knucklehead will have very low lift (.270"?) due to its 1:1 rocker arm ratio. and the panhead will have coil bind (and potential valve-to-piston interference) with the reverse condition; tall lobe X 1.5 rocker = .540" lift. A knucklehead with a J has .283" lift.

    W/r/t use of a J cam in a panhead - yes, it works OK in an FL. However, the EL (18% smaller; not a big deal? a 74 is 18% smaller than 90") is a special case, and much less tolerant of long duration for these reasons.
    1. low static compression ratio means low intake vacuum
    2. very large port volume and diameter (same as FL) reduces velocity
    3. very large 2.13:1 rod ratio (the FL is 1.88:1) traps less cylinder volume @ intake closing with the same cam than a smaller rod ratio

    If you want to use an Andrews cam, I suggest the #1, which is the mildest cam, but it's not specifically mentioned for the EL. Even with its relatively low (.427") lift it may still require spring adjustment.

    H-D knew exactly what they were doing in 1936-39 with the smaller EL manifold and ports, and cheaped out (accountants make very bad engineers) by using the same FL (large) heads in both engines after 1940.
    Last edited by kitabel; 07-01-2019 at 03:06 PM.

  7. #7
    Join Date
    Sep 2005
    Location
    Sarasota, Florida
    Posts
    4,184

    Default

    Great information, kitabel. I've never heard OHV cams explained so well.
    Eric Smith
    AMCA #886

  8. #8
    Join Date
    Apr 2019
    Posts
    27

    Default

    As Eric said, well put. After reading your response, I will shelf the Andrews, and go with a stock cam.

  9. #9
    Join Date
    Jan 2002
    Location
    South Dakota
    Posts
    205

    Default

    Andrews makes a cam for the 61 panhead that I have used for years with great success.
    Carl

  10. #10

    Default

    Not listed currently. What grind number?

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