Cam lobe height

My manual says to measure the lobe height and outer diameter of the cam journals. I've done this using a very accurate micrometer I borrowed. The lobe heights are 36.3 mm. According to the manual, the tolerance is 35.79 to 35.84 with a service limit of 35.49. My cam journal outer diameter is 22.47 and it should be 21.97 to 21.99. Why are my measurements bigger than the ranges stated in the manual - and does it matter?

 

 

My manual says to measure the lobe height and outer diameter of the cam journals. I've done this using a very accurate micrometer I borrowed. The lobe heights are 36.3 mm. According to the manual, the tolerance is 35.79 to 35.84 with a service limit of 35.49. My cam journal outer diameter is 22.47 and it should be 21.97 to 21.99. Why are my measurements bigger than the ranges stated in the manual - and does it matter?

 

 

Are you sure the cams you have are OEM specific to your model? Assuming you have measured correctly, there is a difference between the S cam, E cam and an aftermarket cam...i.e. Hot Cams, or Webb Cams.

Yes, I think they're the OEM ones as they have 29F. I'm pretty sure I've measured them right as well. They seem to perform OK but It's just a bit odd. I would expect the lobe height to decrease with wear if anything.

Yes, I think they're the OEM ones as they have 29F. I'm pretty sure I've measured them right as well. They seem to perform OK but It's just a bit odd. I would expect the lobe height to decrease with wear if anything.

 

Hard to figure. If the engine is running fine, I guess just go with it. Not having a measurement when it was new, there's nothing to really compare to.

 

My manual says to measure the lobe height and outer diameter of the cam journals. I've done this using a very accurate micrometer I borrowed. The lobe heights are 36.3 mm. According to the manual, the tolerance is 35.79 to 35.84 with a service limit of 35.49. My cam journal outer diameter is 22.47 and it should be 21.97 to 21.99. Why are my measurements bigger than the ranges stated in the manual - and does it matter?

 

What manual are you getting those specs from?>

 

What year and model and country is your DRZ?

 

 

I have two factory service manuals, each has different specs for cam height

 

2002 DRZ400 E

2002 E Cam wear limit.jpg

 

2000DRZ400 S

2000S Came wear limit.jpg

What manual are you getting those specs from?>

 

What year and model and country is your DRZ?

 

 

I have two factory service manuals, each has different specs for cam height

 

attachicon.gif2002 E Cam wear limit.jpg

 

attachicon.gif2000S Came wear limit.jpg

 

What manual are you getting those specs from?>

 

What year and model and country is your DRZ?

 

 

I have two factory service manuals, each has different specs for cam height

 

attachicon.gif2002 E Cam wear limit.jpg

 

attachicon.gif2000S Came wear limit.jpg

 

I got the specs from the Clymer manual. They are the same as the ones you have listed. Mine is a UK DRZ400e from 2000. However the engine has been replaced with an SM engine (date unknown). The figures I quoted are for the exhaust. I think I have the S/SM cams (they have a D etched into the end), The lobe heights (36.30) are within spec for the SM but they are bigger than they apparently were when they were new (35.79-35.84) according to the Clymer manual. That's what confuses me 

I got the specs from the Clymer manual. They are the same as the ones you have listed. Mine is a UK DRZ400e from 2000. However the engine has been replaced with an SM engine (date unknown). The figures I quoted are for the exhaust. I think I have the S/SM cams (they have a D etched into the end), The lobe heights (36.30) are within spec for the SM but they are bigger than they apparently were when they were new (35.79-35.84) according to the Clymer manual. That's what confuses me 

3 points..

  1. My notes show D marked cam is a S/SM model Intake cam. Are you saying BOTH cams are imprinted with a  "D"  If you so you have TWO intake cams from a DRZ400S or SM
  2. Clymer manuals are great for lining your parrot cage, but not much use as a Service manual.
  3. Ockham's razor applies here.. The cams can not "grow" so that did not happen... Your spec is wrong, the cam you think you are measuring with a known spec is a different cam, or your measuring wrong.

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