Valve train or timing issue?
04-17-2016, 12:43 PM
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Valve train or timing issue? I just finished my first build last Monday evening. Prc 225 heads, 228r cam, trunion upgrade, ls7 lifters, chromoly 7.450 pushrods, zo6 timing set, melling oil pump, and .040 cometic gaskets. Went to fire it up Wednesday with my tuner in the car to make sure nothing went snafu. Didn't start, but pulled a camshaft position sensor code. Changed the sensor, and replaced the oil pressure sensor because I had broke it, put everything back together, and it still wouldn't start. Checked the shader valve for fuel pressure, pulled a few plugs to check for spark, and both checked out. Pulled the valve covers to observe the rocker arms and check everything there. Low and behold one of the pushrods snapped, exhaust cylinder one. I put a stock pushrod in on the off chance it was a faulty pushrod, and it bent the stock one. Ok, frozen valve, take a hammer to it lightly and tap on the top of the valve, pulled the intake cylinder one pushrod and put it in the place of the the exhaust, and put a stock back in intake cylinder 1. After torquing them, though, the rocker arm does not make contact with both the pushrod and the exhaust valve at the same time. I'm kind of lost now guys, where do I go from here?
PS, when I installed the z06 timing set, I triple checked the cam sprocket dimple was 6 down, and the crank dimple was 12 noon.
PS, when I installed the z06 timing set, I triple checked the cam sprocket dimple was 6 down, and the crank dimple was 12 noon.
04-17-2016, 01:46 PM
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Sounds like you may need to verify pushrod length. Did you measure by any chance?
04-17-2016, 06:42 PM
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I did not check the pushrod length, just torqued them all to 24ftlbs, I have since got a checker and am reading up on proper procedure.
Yes I checked piston/valve clearness and I am all set. It only happened on the exhaust valve cylinder 1.
Yes I checked piston/valve clearness and I am all set. It only happened on the exhaust valve cylinder 1.
04-19-2016, 07:18 AM
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