Topic: Camshaft Timing Question

[mdl91881]

So today I decided to put a "new" K cam in the bike.  After i pulled the valve cover i decided that i would check the cam timing of the existing cam before I took it apart to install the new cam.  Here is what I found... I rotated the crank to TDC of the compression stroke of cylinder 1.  I verified it was the compression stroke because cylinder 1 rocker arms had wiggle in them.  The cam notch was pointing at 6 o clock.  I rotated the crank 360 degrees, which should be TDC of the exhaust stroke of cylinder 1, verified because the was no wiggle in cylinder 1 rocker arms, and now the cam mark was at the 12 o clock position.  To me this seems like the cam is 180 degrees off. Am i missing something? The bike was running fine prior to opening the valve cover. 

[dave the welder]

nope just compare the mark on K cam in relation to the lobes to the matic cam.if the phasing is the same go for it

[mdl91881]

I just wasnt sure, shop manual says to install cam with mark at 12 o clock position at TDC of 1/4 cylinder.  It doesnt specify if TDC of compression or exhaust stroke.

[Davez134]

I was thinking about this for a minute after reading your question. Since pistons 1/4 move together relative to the crank, it would be the lobes of the cam that determine which piston is on exhaust and which is on compression right? So that's why manual doesn't or can't specify any further.

[mdl91881]

Davez134, That makes perfect sense about the lobes on the cam.  It just didnt make sense to me to even mention the can mark to be installed at the 12 o clock position if it doesnt even matter. 

[mdl91881]

http://forums.sohc4.net/index.php?topic=107242.0

[mdl91881]

The above link confirmed my question about being 180 degrees off.  So when I went to remove the old cam I noticed a number stamped on it.  I believe it to be R1, from what I was able to find this appears to already be a K series cam,  I attached a pic of the stamping on the cam to confirm

[Jerry Rxman Griffin aka MuthaF'er]

It's been said on here a zillion times already that stock cam markings mean nothing.