I came home a few weeks ago from the military and want to get my motor together. I have been having nothing but issues with the valve train. I cant seem to get the advertised lift with rocker ratio. My cam is a comp cams 20-745-9 with .480 INT EXH with 1.6 ratio. I have harland sharp 1.7 adjustable rocker arms and cant seem to get better than .460 lift with a dial indicator on the spring retainer. I cant understand why. I previously had hughes 1.65 rocker arms and couldnt do much better. The way i see it I should have netted a .497 with the hughes and now a .510 with the harland sharps. Also the push rod length with the harland sharps is really short and on a big angle in relation to the lifter. Im looking at 6.610" pushrod length before preload. The hughes 1.65 rockers needed 6.85" pushrod. I am really getting annoyed. Looking for any offers of help. Im ready to push the motor over a cliff. Thanks again

 

If the engine isn't running, you won't have oil pressure for the hydraulic lifters, and you won't get full advertised lift.

Did you put new valve springs on your heads? Stock springs only support up to .480 lift.

 

The engine has never been fired. I took an old lifter apart and filled it with washers and left it .080 deep. This would be the preload. I then took my measuring pushrod and adjusted it snug and rotated the engine. The dial indicator was placed on the top of the spring retainer. Im not sure why its not reading gross lift with the rocker ratio. Unless comp cams sent me the wrong cam. It was put in witr a degree wheel. I have a 1.7 ratio rocker and im not even getting the advertised lift at 1.6. Also the 1.7 harland sharp rockers seem to place to much angle on the pushrod. I dont think i am going to use them. I cant figure out the lift thing. I am going to try and measure the lift at the lifter to get the lobe lift and see what it is.

Thanks