Valvetrain Question
Thread Starter
Racer
Joined: Dec 2005
Posts: 426
Likes: 0
From: Northern Virginia
Valvetrain Question
After searching the Forums, I still havn't been able to find GM's specs on a '97 C5 (lift, duration, and seperation) Can any one help me with a resource or the #'s? I want to calculate the change from an increased rocker ratio(so your help would be for a good cause).
Also I'm looking to upgrade the valve train when I replace a bad
lifter(s).
I need help deciding on Crane or Comp cams systems (lifters, springs, push rods and roller rockers w/ misc hardware).
The biggest difference seems to be in the roller rockers: Crane has cnc aluminum body 1.8 ratio, and Comp pro-magnum uses chrome moly steel body with a 1.85 ratio and costs a little less.
Any one have experience or know any other difference? Bearings? Noise? Durability? Performance?
Thanks guys
Also I'm looking to upgrade the valve train when I replace a bad
lifter(s). I need help deciding on Crane or Comp cams systems (lifters, springs, push rods and roller rockers w/ misc hardware).
The biggest difference seems to be in the roller rockers: Crane has cnc aluminum body 1.8 ratio, and Comp pro-magnum uses chrome moly steel body with a 1.85 ratio and costs a little less.
Any one have experience or know any other difference? Bearings? Noise? Durability? Performance?
Thanks guys
Last edited by dmiz0420; Apr 23, 2006 at 09:10 AM. Reason: wording
Thread Starter
Racer
Joined: Dec 2005
Posts: 426
Likes: 0
From: Northern Virginia
Thanks and more rocker info
Thanks looks like the stock cam could use some advance and the 1.8 ratio crane would get it to .499/.507.
I'm not sure I understand how the difference in design can make a difference. To me the 1.85 would just magnify the cam lobe that much more, greater lift and duration. But thats just taking the manufacturer at their #'s, and I just dont know the physics and theory of it... yet.
***I did find out that comp cams have clearance issues on early model ls1 engines (00&newer)and need $200 .5in valve cover spacers w/ bolts.
I looked at yella terra rolling rockers and they state nothing other than the stock hardware to be installed with no clearance issues. Any Ideas or experience?
I'm not sure I understand how the difference in design can make a difference. To me the 1.85 would just magnify the cam lobe that much more, greater lift and duration. But thats just taking the manufacturer at their #'s, and I just dont know the physics and theory of it... yet.
***I did find out that comp cams have clearance issues on early model ls1 engines (00&newer)and need $200 .5in valve cover spacers w/ bolts.
I looked at yella terra rolling rockers and they state nothing other than the stock hardware to be installed with no clearance issues. Any Ideas or experience?
Thread Starter
Racer
Joined: Dec 2005
Posts: 426
Likes: 0
From: Northern Virginia
Thanks and more on comp
Thanks looks like the stock cam could use some advance and the 1.8 ratio crane would get it to .499/.507.
I'm not sure I understand how the difference in design can make a difference. To me the 1.85 would just magnify the cam lobe that much more, greater lift and duration. But thats just taking the manufacturer at their #'s, and I just dont know the physics and theory of it... yet.
***I did find out that comp cams pro mognums have valve cover clearance issues on early model ls1 engines (00&newer)and need $200 .5in valve cover spacers w/ bolts.
I looked at yella terra rolling rockers and they state nothing other than the stock hardware to be installed with no clearance issues. Any Ideas or experience?
I'm not sure I understand how the difference in design can make a difference. To me the 1.85 would just magnify the cam lobe that much more, greater lift and duration. But thats just taking the manufacturer at their #'s, and I just dont know the physics and theory of it... yet.
***I did find out that comp cams pro mognums have valve cover clearance issues on early model ls1 engines (00&newer)and need $200 .5in valve cover spacers w/ bolts.
I looked at yella terra rolling rockers and they state nothing other than the stock hardware to be installed with no clearance issues. Any Ideas or experience?
Thread Starter
Racer
Joined: Dec 2005
Posts: 426
Likes: 0
From: Northern Virginia
More info needed
I'm trying to fix a bad lifter and beef everything up before next weekend's track event, I figured untill I know more about what cam properties makes a good road race cam I woulfd hold off and change the cam in due time and the valvetrain would be ready.
That being said
Is it much more work to change the cam when changing the lifters?
Wouldn't the timing chain need to be changed as well?
Does any one offer a kit or package? A good road race track (scca) cam, lifters, push rods, rolling rockers and valve springs?
See Pandora's box, but I only want to open it once
That being said
Is it much more work to change the cam when changing the lifters?
Wouldn't the timing chain need to be changed as well?
Does any one offer a kit or package? A good road race track (scca) cam, lifters, push rods, rolling rockers and valve springs?
See Pandora's box, but I only want to open it once
