valve adjustment/lifter problem
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Joined: Nov 2009
Posts: 7
valve adjustment/lifter problem
Hello,i have a olds 403 freshly rebuilt.I put the Lunati voodoo cam 213/219 - .488/.499 in it.I have the 7a heads,also rebuilt with the 2.00 intake valves.New lifters,pushrods,stock rocker arms,bridges and springs.It runs strong and seems to have alot of power in the 1978 Trans am with 2.56 rearend.Everythings good except ,sometimes when the engine is started,it sounds like one rocker arm is tapping then it will stop after a min or so.Does this mean i have too much preload on that lifter and when the engine is shut down it forces the oil out?Im using the 15w/40 diesel oil.Is that lifter weak?I don't have many miles on the engine yet and dont know if this will eventually cause wear on something.And of course it sounds bad.Thankyou
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Joined: Mar 2011
Posts: 370
From: Orlando, FL
It means that lifter doesn't have enough preload.
It probably makes that noise at cruising speeds but you just don't hear it.
Try to determine which cylinder the noise is coming from, pull that valvecover and remove that cylinders rockers. Get some 600 grit wet/dry sand paper and lay it on a flat surface, such as a glass table or counter top. Put a 50/50 blend on dish liquid & water on the sand paper.
Take the rocker bridge and apply some downward force, not alot, like 5-10lbs and move the rocker bridge in a figure 8 motion, making sure that you are applying even pressure and that the pedestals on the bottom of the rocker bridge is being held flat against the sandpaper as you move the rocker bridge in a figure 8 to remove some height. When you see some aluminum building up on the sandpaper you are probably done. Clean then reinstall, the noise should be history.
Take a fine felt tip magic marker and make a line at the edge of the bottom of each little leg you have on the bottom of the rocker bridge, this will let you know how much you have removed when sanding them down.
It's better not to take off enough and have to resand than it is to sand them down too much and have to go buy some shims by Crane Cams.
It probably makes that noise at cruising speeds but you just don't hear it.
Try to determine which cylinder the noise is coming from, pull that valvecover and remove that cylinders rockers. Get some 600 grit wet/dry sand paper and lay it on a flat surface, such as a glass table or counter top. Put a 50/50 blend on dish liquid & water on the sand paper.
Take the rocker bridge and apply some downward force, not alot, like 5-10lbs and move the rocker bridge in a figure 8 motion, making sure that you are applying even pressure and that the pedestals on the bottom of the rocker bridge is being held flat against the sandpaper as you move the rocker bridge in a figure 8 to remove some height. When you see some aluminum building up on the sandpaper you are probably done. Clean then reinstall, the noise should be history.
Take a fine felt tip magic marker and make a line at the edge of the bottom of each little leg you have on the bottom of the rocker bridge, this will let you know how much you have removed when sanding them down.
It's better not to take off enough and have to resand than it is to sand them down too much and have to go buy some shims by Crane Cams.
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jensenracing77
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Oct 11, 2014 09:53 PM
