pcgamer4life

Just put longtubes on, and I had to pull two rocker arms to clear the driver's side header... (don't ask ) Anyways, I put them back on, just pretty tight, no means of adjustment, whatever. Started it up, and it backfired a bit, drove it around the block, backfired more. Pulled the valvecover (driver's side) and the #7 intake valve (I think it's intake... next to last one) was loose enough to be separate from the valvespring totally. Read up on method of adjustment and learned that a rough estimate is tighten until pushrod won't spin anymore by hand, then roughly 3/4 turn past that. I did that, and it sat for a few hours, I went back outside and the pushrod would turn by hand now. I checked the other valves, and most of them the pushrod turns by hand... atleast on the driver's side. What's this mean? A friend told me that those rocker nuts aren't meant to be taken on and off often, so I ordered 2 new ones ($.80 each) and I'm going to replace those.. but what about all of the other valves/pushrods? Any reason they're loose?

MeanGreen97Z

Lifter made be bad at this point... or you didn't adjust it right. That cylinder needs to be at TDC when you make the adjustment.

pcgamer4life

I'm not overly concerned with that particular rocker... moreso the fact that only 2 of the pushrods won't spin freely, all of the others will. Considering that's a means of judging near proper adjustment, I'm rather concerned with it. I'm going to adjust them with it running soon... I just wanted some input on what could cause them all to be loose?

MeanGreen97Z

When the motor has been off and all the lifters bleed down... they are going to seem a tad loose.

pcgamer4life

I guess that makes sense being that they're hydraulic. Thanks for the input. I'm just going to back them off, replace rocker nuts on the 2 I took off, and adjust valves with the motor running.

GMRL

Setting lash is alot easier than most make it out to be. Just turn the engine over till the lifter is on the base circle. Back the adjusting nut off, with one hand spin the pushrod, and tighten the nut down with the other. As soon as you feel resistance stop, give it another 1/4 turn, and lock the set screw. Ive been doing that way for years and it work perfect.

Dont turn till you cant turn it by hand, thats too much, 3/4 past that is also too much, the lifter will collapse that way.

mpe331lx

The spinning method can cause you to set the rockers too tight. You should Pick the cylinder that you are adjusting the valves (or start at number 1 and go from there). Rotate the engine over until the exhaust valve starts to open, Now the intake [lifter] will be on the cams base circle. Adjust the intake rocker nut untol you have zero lash (move the pushrod up and down by hand, keep tightening it until there is no play inbetween the pushrod and the rocker.) Once it is at zero lash, tighten it 1/4 -1/2 turn (1/4 for race , 1/2 for street)
Next you rotate the engine over, you will see the intake valve reach peak lift and than start to come back up, rotate the engine until the intake valve is almost closed. The exhaust [lifter is now on the base circle of the cam]. Tighten the exhaust rocker the same way you did the intake.

Then you can move on to the next set of valves.