Have you measured xfi280 valve events,were they spot on or not?
I measured yesterday cam events from my cam(cc07-467-8).
Cam is installed straight up with new cloyes 9-3145 timing set.
Measured valve events at 0.006":
Int opens->34deg BTDC
Int closes->77deg ABDC
Exh opens->81.5deg BBDC
exh closes->35deg ATDC

and same at 0.05":
Int opens->6deg BTDC
Int closes->47deg ABDC
Exh opens->55deg BBDC
exh closes->4deg ATDC
Intake centerline was 109.5 degrees measured 0.05" at both side of intake
lobe,and exhaust centerline 115.5degrees.
Cam card: http://www.compcams.com/Company/CC/c...csid=1111&sb=0

 

Where is your dial indicator tip when measuring?

You have:
+3 on the intake open.
-8 on the intake close.
+.5 on the exhaust open.
-8 on the exhaust close.

I can see a couple of things but I think a remeasure is in order. To verify the measuring procedure, try advancing the timing +4 degrees. Check against your earlier results. If it checks out, you may have a different cam than you think. My Comp Cam has a completely different grind number etched into the end than what it is. Mine says XR282HR when it's a XR288HR. Same core I guess but a different grind cut into it.

 

I had replied to your comment in another thread. I interested in how your measurements check out. As it so happens, I'm in the middle of dialing in my cam too. Also checking P/V clearance, etc.

(copied)

I had difficulty getting repeatable results by measuring from the edge of the lifter body. It seems the curve of the dial tip was enough to cause errors as the tip would pivot slightly on the thin edge of the lifter. Greater accuracy was found by placing the dial tip in the pushrod cup. It will register slightly in the oiling hole and does not pivot. I also measure from the tip of the push rod using the oiling hole there. Using the pushrod allows you to align the dial plunger centre line parallel to the pushrod. There's a good visual reference. Even slight deviations in the direction the plunger travels makes a difference.
These are my experiences. Perhaps they compare to yours.

 

Cam advanced 4 degrees:

at 0.006":
Int opens->36deg BTDC
Int closes->71.5deg ABDC
Exh opens->84deg BBDC
exh closes->31.5deg ATDC

at 0.05":
Int opens->10deg BTDC
Int closes->42deg ABDC
Exh opens->58deg BBDC
exh closes->0.5deg BTDC
Intake centerline was 105.75 degrees,and exhaust centerline 119.75degrees measured 0.05"

 

You are getting alot of variation in your measurements. Staight up at .006" you get 291 degs intake duration total
Advance 4, you get 287.5. Thats a decent change and shouldnt be happening if setup is consistant from measure to measure.

Its not uncommon to be withing +\- 2 deg imo, based on how you set things up plus tolerances in cam manufacture.

 

Are you still measuring from the edge of the lifter?

What is the origin of the cam? Did you purchase it new?



Int opens->34deg BTDC
Int closes->77deg ABDC
Exh opens->81.5deg BBDC
exh closes->35deg ATDC

Advancing it 4 degrees is resulting in:

Int opens->36deg BTDC
Int closes->71.5deg ABDC
Exh opens->84deg BBDC
exh closes->31.5deg ATDC

+2 IO
+5.5 IC
+3.5 EO
+3.5 EC

What degree wheel are you using?
Your EO/EC events have consistency. Your IO/IC events don't. Some wheels read differently than others. Obviously you transfer the dial gauge so the setup isn't the same from intake to exhaust?
Your ICL remains consistent (which you say is via the .050" method) so my guess it's something when measuring closer to .006".
Gauge deflection?

 

Measurement take at edge of lifter(no difference if measured at side of lifter cup)
Dial indicator was same angle as lifter, and doesn't move to side of edge of lifter body at top lift.
Cam is from summit(6/16),degree wheel is summit 11" wheel.

Which is right way to take 0.006 and 0.05" measurements
1.take lifter to top of lift and calculate bacwards(from cam card number) 0.006"/0.05" points or
2.zero dial indicator at lifter base lobe and measure from there(there is ~0.03...0.04mm variation of lifter base circle,dial indicator needle backs up that 0.03...0.04mm just before cam rising ramp)
method 1->IVC at 0.006" 75deg,method 2 IVC at 0.006" 77deg

 

You zero on the cams closed base circle and slow roll motor over.

 

Yes, zero on the base circle.
One thing of note, you say " there is ~0.03...0.04mm variation of lifter base circle, dial indicator needle backs up that 0.03...0.04mm just before cam rising ramp".
When this happened to me, it was not the cam base circle that was making the needle move but rather the dial indicator moving.
Try placing the dial indicator plunger IN the push rod cup of the lifter. Not to the side as you mentioned, but directly IN the oiling hole. This will stabilize your measurements and should eliminate the variation you are seeing.

 

I take rotating assembly today to balance shop,so it takes few weeks till engine goes together.