Cam Degree Report And A Question

[Anonymous]

Well, it is all done. Now I'm just waiting on a new valve cover gasket and I can run the beast finally.

The cam degreeing went surprisingly well, especially for a first time procedure. Before installing the slotted sprockets, I laid them over the OEM sprockets to see how the slots lined up on the holes. The slots were very nicely centered, so I installed them on the cams with the bolts in the middle of the slots (by eye, no precision measuring) to start with.

The exhaust cam was not too far out, my first lobe center reading was 103.5 degrees, which is only a bit retarded from the stock setting of 109 degrees. One adjustment and I got it perfect at 109deg. I figure the OEM timing must have been a bit retarded, but not really badly off the design numbers. It was definitely a low rpm setting, though.

The intake was another story. My first lobe center reading was 119 degrees! I know I may not have been perfectly lined up when I installed the slotted sprockets, but I KNOW I was not very far off. By the time I had it at the OEM timing of 110deg, I was almost out of slot in the one direction. So I am sure my OEM timing was WAY goofy on the intake side. Given that the 119degree timing is such a high rpm timing, I figure the thing never got to take off properly.

The good news is, it made 102rwhp and 69ft-lb torque in the OEM configuration. I am hoping for a very noticeable improvement now that both cams are properly set and working together. Do the racers out there have any guesses how much I should pick up with the cams sorted now?


Mark

 

[pano]

Mark,

I finally took mine for a ride last night but I live in a residential area so I really could not put it to the test. I have my bike wheels in my car to drop off at the bike shop for installation of new tires this afternoon so I won't ride it again until next week. The bike seemed tighter, quieter, and pulled well but I was only able to rev it from 5 - 8k in one short staight in 2nd gear.

My initial #s before I changed anything were IN 119.5 and EX 99.75. I also have definate chain stretch. I chose not to change the chain because I plan for a rebuild next winter.

I too set mine to IN 110 and EX 109 but when I put my sprockets in I marked on the cam chain where the 3 arrow and 2 arrow where for the stock sprockets, made sure they where the correct number of links apart and inserted my slotted sprocket 3 and 2 arrows accordingly. What is interesting is when I was all done my IN sprocket is pretty centered but my EX is skewed a bit to one side. Just the opposite of yours.

I know my 1, 2, and 3 arrows where generally pointing in the correct direction but I did not specically recall if the #1 was exactly at the gasket surface. I know that yours was based on reading your posts. It makes me wonder if I am a tooth off or if this difference may be within the tolerance of machines parts.

Years ago I had mine dyno'd when I had the stock airbox and a 4-1 pipe and had 92rwhp. I know going to pods and the stage 3 made an improvement but I never had it re-dynoed to find out what it was.