How can you tell if you have flat cam lobes?, Strange lash issue |
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How can you tell if you have flat cam lobes?, Strange lash issue |
tornik550 |
Jun 15 2012, 02:27 PM
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#1
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Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
I am paranoid of developing flat can lobes on my recent engine rebuild. I am paranoid cause I have heard so much crap about the cam that I used- scat c45. I am asking this more for curiosity sake. I had a strange issue but I am certain it's unrelated. I set my valves on cyl 1 to 0 lash (chromoly pushrods). I did that at tdc for that cyl. Te intake and exhaust valves. Seem to lift normally. The issue is that at a different point in the cycle (other than tdc or full lift) the valves are very loose. The valves go back to zero lash at TDC. The compression is actually about 5 points better on that cylander. I think it's possible that the rocker shaft bolts may have loosened a bit, however I've already removed them. It doesn't sound like a flat lobe to me.
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toolguy |
Jun 15 2012, 08:26 PM
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#2
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Senior Member Group: Members Posts: 1,270 Joined: 2-April 11 From: San Diego / El Cajon Member No.: 12,889 Region Association: Southern California |
once again. look where the distributor rotor is pointing. . . Back to basics. . . . the cylinder has 2 top dead centers per 4 cycles. . . . . as there are 2 rotations for each four cycle cumbustion cycle.
It sounds like you are setting the valves at top dead center but 180 degrees of camshaft rotation out. . . that would be top alright , but of the exhaust stroke and beginning of the intake stroke, where the cam has overlap for scavenging effects. . you need to turn the engine one full rotation or see if the valves on #3 are both loose since the firing order is 1-4-3-2 If 3 is both loose, then that's the cylinder that it at TDC and the one you should be adjusting. . |
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