I need a little help...
10-27-2006, 05:23 PM
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I need a little help... Lifter Preload Question My valve train has always been a bit noisey so I finally decided to check the preload. Well, with the 8.100" pushrods, I would take it to zero lash then tighten to 22ftlb. I am using ETP 225 heads with stock rockers and ETP stands. Well it ended up being only 1/4 turn on the rocker bolt. I have trickflow pushrod checker but it is about worthless since there are no marking on it and my micrometer doesn't open up that much. So I tried to do a little math and a little searching and found that 1 full turn on the rocker bolt = .049". So I figure I need a 8.200" pushrods with a .030" shim under the rocker stand and that will put me at about .085" preload. I am using LS7 lifters. So I order the 8.200" pushrods and they come in. For the hell of it, I install one to see where I am at. I tighten the bolt to zero lash first then I tighten it down to 22ftlb. Well I get 1 3/4 turns which is good right??? But I see the valve spring starting to compress a little. Is this because the lifters were too pumped up and needed to bleed down or what??? Am I missing something here??? Thanks in advance.
Last edited by 2001 Pewter WS6; 10-27-2006 at 08:42 PM.
10-27-2006, 08:39 PM
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Update.. I put .040 shims under the rocker stands and put it back together. I got just over 1 full turn of preload. Started it and it seems normal but the valve train is still noisey. It is almost like the FAST intake is magnifying the sound a bit. Is it just the valves slamming shut because of the dual springs and XE-r cam??? Would I be better off with the 1 3/4 turn of preload?