Cam end play

mk2007 · #1 06-29-2008, 05:40 AM

I have a project bike with 4 Andrews PB+ cams.
When measuring the free end play as it is explained in the original manual, through the lifter base hole, it&nbsp\\;measure way more&nbsp\\;than the recomended distance between 0.001-0.005 inch.&nbsp\\;I used a gauge with 0.032 inch&nbsp\\;and it slided right in. Ive also have put&nbsp\\;two shims on all four cams with not much better result.
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IÂ´ve read somewher that it is better to have much play than to little, but this seems a little to much...
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Any input? Thanks in advance.

GA Ironhead · #2 06-29-2008, 06:41 AM

In 1982 the MoCo released a service bulletin that recommends not shimming the cams and states that they have discontinued use of shims in production. They state a minimum clearance of 0.005" for all cams except the rear intake (0.004"). There is no maximum.

I've included the bulletiin - page 1 is the page you're interested in. While you can shim, you run the risk of the shims tearing up and ending up in your cam chest. If you do decide to shim, try using the thickest shims possible, rather than multiple thin ones to get the same result.

[IMG]local://upfiles/53975/56B4D5FAB55F4A63AD278D620F880327.jpg[/IMG]

[IMG]local://upfiles/53975/605EA35CA3BE4AB5A095F47D1227E7F1.jpg[/IMG]

[IMG]local://upfiles/53975/DF1A93E5513E4F3492DEF9DB66D1E8FB.jpg[/IMG]

Doc 1 · #3 07-06-2008, 12:13 AM

Quote:

ORIGINAL: GA Ironhead

In 1982 the MoCo released a service bulletin that recommends not shimming the cams and states that they have discontinued use of shims in production. They state a minimum clearance of 0.005" for all cams except the rear intake (0.004"). There is no maximum.

I've included the bulletiin - page 1 is the page you're interested in. While you can shim, you run the risk of the shims tearing up and ending up in your cam chest. If you do decide to shim, try using the thickest shims possible, rather than multiple thin ones to get the same result.

[IMG]local://upfiles/53975/56B4D5FAB55F4A63AD278D620F880327.jpg[/IMG]

[IMG]local://upfiles/53975/605EA35CA3BE4AB5A095F47D1227E7F1.jpg[/IMG]

[IMG]local://upfiles/53975/DF1A93E5513E4F3492DEF9DB66D1E8FB.jpg[/IMG]

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The reason Harley doesn't use shims today is because of the way the gears are cut...the cams thrust to the cam plate as the engine runs.&nbsp\\; Unlike Iron Heads that the cams slap back and forth in the case making all kind of racket...bottom line if you have the older bikes the cams ARE to be shimmed from .001 to .005 end play.

mk2007 · #4 07-06-2008, 04:38 AM

I sent this question also to Andrews since I got cams from theme. Here is question and reply.
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Question:
(I have a 1974 XLH Sporster. it has 4 Andrews PB+ cams. When checking the end play on Cam #1, with instructions from original manual, it says that it should be minimum .001 to maximum .005 inch clearence. My measurement indicates that it is about .032 inch clearence. Is this to much? Thanks in advance for reply.)
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Reply from Gary Wallace www.andrews.com:
(HD or aftermarket suppliers have shims to correct too much end play. Use the thickest shims available, the thinner shims can get torn up (below .007" shims). Some engine builders do not use the shims at all, the shims can tear and cause issues. End play can be more than what HD specifies, only creates more noise, if any.)
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I have already mounted it all togheter with no shims,&nbsp\\;put gaskets on with permatex, and torqued bolts&nbsp\\;to 12 Newton Meters. Who should I listen to? Andrews or Doc1? Hate to think of taking it all apart again.
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Any "serious" reply would be much appriciated...
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piniongear · #5 07-06-2008, 07:05 AM

I can give you a serious suggestion regarding the cam shims.........use them! The .005 and the .007 thickness were made to provide a combination that would suit any clearance condition.
For example two 'sevens and one five' will give you .019, or 'two sevens and two fives' will give you .024 etc, etc. This is the way you get the clearance THAT IS REQUIRED of between .001 and .005 maximum.
Some guy brings up a bulletin dated 1982.........it means nothing regarding a machine made in 1974. A 1982 Sportster is not the same as an older ironhead. Always use the service information relating to your specific year model and forget the newer stuff. I imagine the gear cuts were changed on the newer cams to get around using shims (perhaps).
But your 1974 needs the shims, so use them.
Also, the .005 shims will not self destruct any quicker than the .007 shims. Install them properly and you will have no trouble at all. The only shims I have ever seen eaten up came out of an engine that had been run without oil......duh!
pg

Doc 1 · #6 07-06-2008, 07:55 AM

Andrews build cams not motors.....I totally agree with Piniongear here. I never seen atorn shim unless the cams where shimed too tight then you will see a torn shim that is blued from heat which is evedience of being too tight.
Be careful with that permetex too.