valve train pushrod geometry setting, weird question... maybe not |
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valve train pushrod geometry setting, weird question... maybe not |
orange914 |
Mar 18 2008, 05:23 PM
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#1
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
following the step by step valve geometry i've got a few possible issues? when no shims used and exhaust and intake geometry is set the swivel feet are almost bottomed out (almost no adjustment left). so next it was shimmed with .025, the geo/swivel tightness got better (not so close to bottoming against swivel) when shimmed with .040 shims i have more space to adjust up left before swivel contacts rocker (3/4 to 1 turn).
bottom line it seems to work out better with .040 shims. with no shims it has wider range of measurements between each valve -and- closer swivel foot to rocker arms. 1] is .040 shim o.k.? 2] if o.k. is 3/4 to 1 turn until swivel foot hits the bottom of the (modified) rocker acceptable? yes they are o.e.m. swivels from a 2.7 3] if not o.k. can i remove .030 or ? more from rocker arm 4] if none of the above is good what am i needing to do to correct this? mike |
Jake Raby |
Mar 19 2008, 05:58 PM
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#2
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
QUOTE The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. That means you have 3/4 of 1mm of valve adjustment allowable.. If your valves stretch that far they'll snapp off. |
orange914 |
Mar 19 2008, 11:30 PM
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#3
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
QUOTE The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. That means you have 3/4 of 1mm of valve adjustment allowable.. If your valves stretch that far they'll snapp off. jake, with no shims we measered .440 INT. lift, and .419 EX. lift. Perfect valve train geometry at half lift had a bigger difference in lengths between intake and exhaust pushrods without a shim, but they were closer with .040 shims. (1)- i am not clear if .040 is advised or not needed? (2)-with no shims, having approx. half turn at most, will i have problems with swivil foot/rocker-arm interference? (3)-is it better to have a more equall exhaust and intake total lift that adding a .040 shim? |
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