#'s for Degreeing Yz-F cams

[SFO]

Ok Rich,
I got my head back from Kibblewhite and they did an awesome valve job!
Bored the throats of the intakes, recut the bowls to unshroud the chamber...
After I measure the volume of the chamber I will assemble the top end.
Then I can make a fixture to hold the indicators over the buckets squarely.
And last but not least what do you recommend for lobe centers?
Are you using .050" lift for zero?
Are you shimming to zero lash as well?
This is the first bucket motor I have done and I feel kinda lazy, like I don't wanna shim it to zero. I never thought I would miss rockers!:eek:

 

[SFO]

Hey Rich....

Wadda ya say man?
Thanks in advance.
Bill

 

[Rich Rohrich]

Sorry for the delay Bill, I haven't been watching DRN much this weekend.

Based on a rough guess of how your cylinder head currently flows here's my thoughts. Assuming a horsepower peak in the 8000-8500 range and torque peak about 3000 rpm lower I would start with a 104 intake LCA and a 106 exhaust LCA. I don't think it's really necessary to shim to zero for your purposes. I usually use .040" on either side of the nose as my checking height with good results.

My YZ444F is currently set at 107 intake LCA and 108 exhaust LCA using the full stock exhaust system, 13.9:1 compression. and mildly modified cylinder head. After DirtWeek I'll get the adjustable cam sprockets and do some testing with data acquistion.

 

[SFO]

Thanks Rich,

104 and 106 sound right.
I will keep you "posted" as to my progress.
Thanks, Bill