Cam lift and valve spring limits
Thread Starter
Teching In
Joined: Feb 2009
Posts: 20
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I have a Comp Cams 54-000-11 custom cam with the following specs: adv dur 289 (intake), 289 (exhaust); dur @ .050 is 239 (int), 239 (exh); lobe separation-111.5; valve lift is .651 (int), .608 (exh). I have to change the valve springs because I broke my #7 intake valve spring. Obviously I have too much lift for the springs. I have stock LS6 heads (243 cast) w/ stock springs. I bought the car the way that it is. I'm trying to figure out the method to the madness. This car has left me with more questions than answers.
Thread Starter
Teching In
Joined: Feb 2009
Posts: 20
Likes: 0
Here is a picture of the broken spring. It appears I was mistaken, the valve springs are not stock, they are dual springs. I don't have a lot of time during the week to work on my car so I just glanced, saw the broken valve and professed that the sky is falling...lol. I ran a fiberscope into my cylinder through the spark plug hole and looked to see if there was any damage. The piston was untouched (probably because of the dual valve) so I think I'm just going to change the spring and call it a day. The next hurdle is finding out what type of dual spring I have and the lift parameters. Take a look and tell me what you think.
maybe patriots? kinda look like prc duals but those would be pushing the lift limits. with 243 heads Id do two things, first change the cam to something better for the heads, and second get a new set of springs. If it broke one its gonna break more.
