New Cam

Discussion in 'Softail Models' started by traveller, Oct 12, 2013.

  1. traveller

    traveller Member

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    Just a question for my intellectual superiors. On a 88 twin cam are there any clearancing to be done to install a S&S 570 gear drive easy start cam.
     
  2. Fastlinnie

    Fastlinnie Member

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    The Valve springs will need to be replace with high lift springs. and you need to check the run out on the crankshaft. I would check that before I got the cams.
     
  3. traveller

    traveller Member

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    thanks for the info, would you know how much run out is acceptable.
     
  4. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    .003 is the rule of thumb. Andrews calls for .003 or less. S&S probably isnt much different.
     
  5. Fastlinnie

    Fastlinnie Member

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    003" Is what s&s has in the specs. Hope this is some help and good luck.
     
  6. traveller

    traveller Member

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    thanks, it's what i like about this forum. good info.
     
  7. dolt

    dolt Senior Member Contributor

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    Depends on the year. '05 was the year beehive springs were introduced and I know you can run cams with .555 lift with no issues but not sure about 570; coil bind could be an issue. You could certainly mock up and check and if an issue replace the springs with the '07 or later beehives that will accommodate lift up to .600.

    I would question the cam selection for an 88" configuration though. There are better choices for a bolt in cam; like the S&S 509 or 551, the Andrews 21 or 48. The pre-'06 heads signed off about .400" lift, so you really don't need a hi lift cam. It's not that the heads stop flowing but the flow really slows down above .400" lift and they are completely done by .500" lift. Might want to re-think your cam selection.

    Also need to consider changing tensioner shoes, inner and outer cam bearings while your at it.
     
  8. dolt

    dolt Senior Member Contributor

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    If you are asking if any clearancing need be done in the cam chest, again, if an '05 or later, no worries. However, if you do decide to install 570s in an earlier model, you should check the lobe to main bearing housing and lifter block clearance. Probably OK but good idea to check; should have at least .030" at both places.