dgreg

how would a person hold the valves up with out putting air in the cylinder. i heard rubber bands somehow. i got an hour till i go back and finish i am just looking for some tip or pointers.


thanks

Alex94TAGT

Stock engine?

I just put the cylinder at TDC and let the valves rest on the piston. I'd start at cylinder #1 and follow the firing order -- that way you can also adjust valves as you go along. Two birds with one stone... saves time.

dgreg

yeah stock but we are having trouble getting it at tdc. we got it on number one but then on 8 how would you find tdc?

Alex94TAGT

Easy. Turn the crank 90-degrees clockwise. It helps to make a mark on the crank pulley (at 12:00 when @ #1 TDC) with white-out pen so you can see what you're doing. In other words:

12:00 - #1 TDC
3:00 - 8
6:00 - 4
9:00 - 3
12:00 - 6
3:00 - 5
6:00 - 7
9:00 - 2
(Two rotations of the crank = 1 rotation of the camshaft = 1 full engine cycle)

Just make sure you're starting at #1 TDC. If you're at #6 TDC, you'll quickly run into a surprise.

Alex94TAGT

For clarification, "Top Dead Center" refers specifically to when the piston is at the top of the compression stroke -- both valves should be closed. If the intake valve is open (intake lifter is up), then you're at #6 TDC, and you need to rotate the engine one full rotation to get to #1 TDC.

I usually just remove the #1 cylinder spark plug, cover the hole with my thumb, and rotate the engine with my other arm. On the compression stroke, you'll have air rushing past your thumb -- when you get to the top of that stroke, you know you're at #1 TDC.

dgreg

thanks alot man. that helps out alot.

BALLSS

if you have the crank at 12 oclock you can do cyl 1 & 6, turn 90 degrees and do #8 & 5, turn 90 degrees do #4 & 7, turn 90 degrees and do #2 & 3.

Then go back and lash valves one at a time or the GM method of the various intake/exhaust, rotate engine 360 and do the others.

The valve will only drop about 1/4" with piston up

rkinney

This is how I do it also. Makes it easy!

dgreg

alex your advice was right on. but now i have another question. was the new springs i now have a lil lateral movement. on the springs that i havent done there is no movement. is this because the lifters are hyd and they just arent applying pressure on the rocker due to the engine not being on and no fluid is not moving. they are the stock lifters and rockers and the spring are the crane dual spring kit 10831 or something like that.

thanks for the help( hopefully can finish tomorrow

Alex94TAGT

Lateral movement of the spring, or lateral movement of the rocker arm(s)?

The spring itself should not move around. The keepers and retainers hold the spring centric to the valve, and the valve should be held fairly steady by the valve guide. If there's a lot of movement there, you may have excessive wear on the valves and/or valve guides.

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Now, if the rockers are moving around, this is normal to an extent, but I need to be clear in regard to what is 'normal' and what is 'not normal':

As you described, factory lifters are hydraulic, which means they pump up with oil. There's a hydraulic "plunger" inside, which the pushrod sits against -- which is why we give our lifters a preload. That is, once you find zero lash, you give an extra quarter or half turn preload to seat the plunger a bit. This is what allows the lifters to take up any valvetrain slack when the engine is running, as they pump up with oil and get rid of any gaps.

Because of this, it's vitally important that you set the lash ONCE and only ONCE. The lifters will bleed off with the engine not running. So, if you adjust the rocker arm and later come back to find it loose again, DONT readjust it unless you completely remove the rocker arm nut and start from scratch, being very careful to feel for zero lash (slight drag as you rotate the pushrod between index finger and thumb -- no up and down movement). Otherwise, it's possible to double-adjust the lash, winding up with a far-overtightened lash adjustment. This can cause problems when you start up the car, as the valve might never fully close, and you can collapse the lifter.

As such, it's 'normal' for the self-aligning rockers to rotate a little, back-and-forth, on the valve. It's just because there's no pressure holding it in place, but that will change once you start the engine and build pressure. The old rockers are probably still sitting on pumped up lifters, which is why they are so tight. Also, you're likely trying to twist them while their corresponding lifter is on a cam lobe (so there's a couple hundred pounds of force between the lifter trying to open the valve & the valvespring trying to close it).