Z06 Breaking Valve Springs
04-29-2011, 08:18 PM
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Staging Lane
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Z06 Breaking Valve Springs Iron 402, tfs 215, 239/243 625/625 lsl comp cam, harland rockers
Last month I broke a spring on a used motor I picked up , its a 402 built by hke, I knew the springs had some miles and replaced the set with patriot golds.
A month later i put the car on the dyno and at 5000rpm it loses 150hp by 6500, pullthe covers and broke another spring, opposite head. #7 exhaust valve.
Ive been told my rockers are heavy, the trick flow valves are heavy and that combined with lsl lobes is putting extra pressure on the spring. Ive been told the new prc eht .675 lift springs should solve my problem.
Well come to find out there are some needle bearings under my valve cover too! Now im worried I have a bad lifter. Any suggestions? I might have a chance to swap on some yella terras which are lighter than my harlands.
Last month I broke a spring on a used motor I picked up , its a 402 built by hke, I knew the springs had some miles and replaced the set with patriot golds.
A month later i put the car on the dyno and at 5000rpm it loses 150hp by 6500, pullthe covers and broke another spring, opposite head. #7 exhaust valve.
Ive been told my rockers are heavy, the trick flow valves are heavy and that combined with lsl lobes is putting extra pressure on the spring. Ive been told the new prc eht .675 lift springs should solve my problem.
Well come to find out there are some needle bearings under my valve cover too! Now im worried I have a bad lifter. Any suggestions? I might have a chance to swap on some yella terras which are lighter than my harlands.
