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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tornik550 |
Jun 16 2012, 08:47 PM
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#2
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Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
My engine does the same thing as yours, toolguy. Dave- was this meant for me or toolguy? And what is it you figured out? Did you just change to the "opposite valve" method (AKA the Cap'n's method), or did you figure out something else? --DD Just a little bit ago I tried both methods to see if I would get different results- I did not. I did however find that the issue is much less severe that I thought. If I set the valves to zero lash at TDC on the compression stoke for a specific cylinder- when that cylinders intake or exhaust valve is fully open, I still am getting a small amount of lash in the other valve- however what I found is that it is MUCH less that I thought. At compression cycle TDC- I cannot feel any rotational movement- when the opposite valve is at max lift I can feel a VERY slight amount of rotational movement. I tried to measure the movement and was pleased to find that I could not fit my smallest feeler gauge between the stem and foot- my smallest gauge is .0015". I also found that it occurs on all cylinders. The engine was running great so I am just going to reassemble and forget about it. |
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