alright so just about done degreeing the cam today and an .050 before the intake valve was at max lift the wheel said 83 degrees, and .050 after max lift, it was 172. after adding these 2 and dividing by 2 i found that the highest point on the intake lobe was at 127.5 degrees and according to by cam card it should be 112. So this means that i need to retard my cam 15.5 degrees, but the only cam degreeing kits go up to 8 degrees, so this is where i am confused, could i have done something wrong? has anybody done this before? do all my numbers seem correct?

 

ok so i was thinking about it and i guess i will try skipping a link backwards and see how many degrees that gives me...

 

definately doesnt sound right. make sure the dots were lined up initially from the crank gear and cam sprocket.

Then do it again. make sure you are seeing true max lift point

what cam is this? hydraulic or solid/mechanical? Is it a symetrical lobe design or asymetrical custom grind? Also check valve timing events at .050" tappet lift to verify cam's timing is correct

 

yea, i thought the dots were as close as they would get, but they were not exact, int a hydraulic symetrical design, lunati 60102lk.

 

Those lobes won't be symmetric. That's a voodoo cam right? I kinda doubt the opening ramp and closing ramps are identical in length.

 

ya thats voodoo, i thought they were, im not positive tho, would this method of finding the lobes degree at its highest point if it was not symetric?

 

FWIW, 1 tooth on the cam sprocket is about 16.3º.

 

yup it is asymetrical, hmmm, im off by 15.5 so that seems lk wat i need to do.

 

make sure its exactly dot tooth to dot tooth and try again to degree it. It aint symetrical but around max lift the lobe should be close to being symetrical at the .050" down marks. Double check the centerline method with the .050" valve timing events methods.

I wouldnt worry as much about the centerlines, just make sure the .050 valve opening closing events are close to the cam card. thats .050" off the tappet which will be times 1.5 or 1.6 or w/e rocker arm you use at the valve.

Another method used alot for asymetrical lobes is checking several points like .050 .020 .015 .010 and .005" before max lift and then .005 .010 and .015 .020 .050 after max lift. get degree readings for every one of those points and add the pairs up and divide by 2 like the .050 method, but more points you use the more accurate your results will be. Compare the results. Likely two of the points around max lift will be result in the same centerline within a few tenths of a degree. that will be the true theoretical Intake centerline. Some lobes you just cant degree right with a simple .050" reading as the lobe could be way different on both sides of max lift point

Also are you using a solid lifter to measure this?? Or a lifter simulator tool in the lifter bore? Hydraulic lifters will collapse and not show the true lift...even with checking springs my LS7 lifters collapsed. i had a extra set laying around so i filled one up with nuts to make it a solid lifter worked good enough for me.

 

I was about to mention that you need to degree the cam with solid lifters but I was beat to it.

 

yea, i will have to go back and make sure everything is prefect, yes i am using solid lifters. alright well i will retry this and see how it works out.

 

ok so i found out that the intake centerline should be 108, not 112, so i started from scratch and found TDC, found the intake centerline, which was 108.5, so i was happy about that, but i noticed that the timing chain had a little play in it. when you turn the crank one way one side of the chain becomes tight and the other is a little loose, then when u turn the crank the other way the opposite side becomes loose/tight. Is this normal?????????