Not really sure if this is going right. I'm redoing my valve adjustment. I installed Scorpion 1.6 rockers with a Lingenfelter 74211 cam. Did that a year ago but there was always a tick. I did that adjustment the shop manual way. Now I'm doing it EOIC and what's got me confused is that when I start setting the preload on the intake valve, the valve spring starts to compress. I've verified that the exhaust is open. It's down about half way. I've set the lash so I can't lift the pushrod and it still spins. As soon. As I put a wrench on it, it's tight right away. Car was running yesterday so the lifters are pumped. They're Johnston lifters.

 

That's the definition of preload. As the oil is pushed out of the lifter, the lifter will compress instead.

That's not right. Probably not far enough off to be a major problem or anything, but not right.

THIMK about valve motion in relation to piston motion for a moment. The int valve opens just before the beginning of the int stroke and closes just after the end; it reaches max lift about halfway down. It's at zero lift exactly 180° away from full lift, at another point where the pistons is about at halfway: the middle of the power stroke. Therefore the zero lift point for the intake is when the exhaust is ABOUT TO open, not when it's already open. Catching the exh when it's JUST BARELY STARTED to open is about the best you can do. Once it's opened any significant amount the int is already well off of its exact zero point.

The exhaust is a bit more straightforward. It reaches max open at about halfway through the exh stroke, therefore the 180° opposite point where you set it to adjust it, is about halfway through the compression stroke. The int closes at the beginning of the comp stroke so you adjust the exh shortly AFTER the int is fully closed.

I prefer the 180° away method. ABSOLUTELY accurate, DEAD ON *****, every time. That method relies on the fact that cyls that are 4 apart in the firing order are 360° of crank rotation (1 full turn) and 180° of cam rotation (½ turn) away from each other. So, in any 2 cyls that are 4 apart in the firing order, the pistons are moving EXACTLY THE SAME; they come to TDC together, etc. etc. etc., only, 1 of them is firing when at TDC, and the other one is crossing over from the exh stroke to the int stroke. Take advantage of this in that when a valve on one cyl is exactly full open, the same valve in the cyl 4 away from it in the firing order, is EXACTLY at zero lift. So for example when #1 int is at peak lift, #6 is ready to adjust.

With either of these methods, either the cruder EOIC or the more accurate one, each cyl comes to its adjustment point exactly 90° (¼ turn) of the crank, after the one before it in the firing order. So for example, you could adjust #1 int, then turn the crank exactly ¼ turn and adjust #8 int, then exactly another ¼ turn and adjust #4, etc. Same for the exhausts: find one, then run through the firing order to do the other 7.

Once you understand how to GUARANTEE that the cam lobe is at zero for every valve, the only other things are, making sure you EXACTLY take up all the VERTICAL PLAY in the push rod WITHOUT depressing the lifter plunger, and then add your preload; and of course, using a correct preload for whatever lifters you have. If you get those 3 things right, then your adjustment is right, and nothing else matters.

 

Ah ok, thanks for clearing that up. So I'm driving the exhaust valve to far down. With regards to the spring compressing. Just so I understand correctly, with a pumped lifter the valve will spring is going to compress a little. Then after some time that spring force is going to exert force back the other way and eventually compress the lifter. Do I have that right? Thanks for clearing up the procedure.

 

Yes it might. The lifter will bleed down to the correct level within a few seconds of starting the engine though, if it hasn't already.

Yes. The system is designed for oil pressure on the bottom of the lifter plunger to hold the plunger up against the valve spring (take up all the play), as long as the "preload" doesn't bottom it out; and for any excess oil inside the lifter, to be allowed to escape on the closing side of the valve motion ramps.

 

I prefer the 180° away method. ABSOLUTELY accurate, DEAD ON *****, every time. That method relies on the fact that cyls that are 4 apart in the firing order are 360° of crank rotation (1 full turn) and 180° of cam rotation (½ turn) away from each other. So, in any 2 cyls that are 4 apart in the firing order, the pistons are moving EXACTLY THE SAME; they come to TDC together, etc. etc. etc., only, 1 of them is firing when at TDC, and the other one is crossing over from the exh stroke to the int stroke. Take advantage of this in that when a valve on one cyl is exactly full open, the same valve in the cyl 4 away from it in the firing order, is EXACTLY at zero lift. So for example when #1 int is at peak lift, #6 is ready to adjust.

100% accurate every time, no matter if the cam is mild or wild.

 

Thanks gents. I did the left bank today. 1, 3, 5, 7. I'm likely to screw it up doing it the other way. After a few rotations there was less force on the valve spring and it was only on two cylinders where it was tighter. I did as sofa mentioned, watched for the exhaust to just start moving then did the intake. I think I had them way to tight before. I tried that method where you lash out all the loose ones, then turn a 1/4, check them all again, turn a 1/4 and so on until there's no more play. Tried that before I came across this EOIC method. Don't think it worked to well and it's an absolute gong show to remove my valve covers so hopefully I won't have to do this again.