Big block valve adjustment question

[70STOVEBOLT]

I adjusted the valves on my 402 with mild cam using the following method: #1 on TDC, adjust intake on 1,2,5,7, exhaust on 1,3,4,8. Rotate 360 degrees, #6 on TDC, adjust intake on 3,4,6,8, exhaust on 2,5,6,7. Tightened nuts while spinning pushrods until they would not spin, went 1/8 turn further. The question I have is this: When I shine a light into the spark plug hole, I can see light in the intake and exhaust ports around the valves. This is with the engine cold, intake and exhaust manifolds off, spark plugs out. Is this normal? If i back the nuts off the extra 1/8 turn, the valves are closed all the way. I don't want to get the valves too tight, and I really don't want to have to adjust them while the engine is running because it makes such a mess. I have tried the clips on the rockers and it still makes a mess. Any advice would be appreciated.

Thanks,
Mark

[geezer#99]

Instead of the spin the rod method use the wiggle the rod method.

[cadillac_al]

That doesn't sound normal to me (valves opening). Are the lifters full of oil? I usually watch the lifter until I see the plunger depress .010-.020"

[70STOVEBOLT]

I have not run the engine yet, but I soaked the lifters in a bucket of oil prior to putting them in.

[geezer#99]

Originally Posted by 70STOVEBOLT

I have not run the engine yet, but I soaked the lifters in a bucket of oil prior to putting them in.

Bingo!!
That's why the spin the rod method doesn't work.
Wiggle them up and down till all the slack is gone.

[DBD]

people like either approach...I find that folks that haven't done it before end up too tight with spin, too lose with shake...of the two loose is better but still not right.

tip is to really understand zero lash...it's not when the pushrod stops spinning or when you can't shake the pushrod...its when there is no space beteween the pushrod and the rocker, but no pressure either. helps to just spend some time loosening/tightening to get a feel where that exact spot is.

too tight now for sure.

soaking the lifters does nothing - they have an internal spring.

[70STOVEBOLT]

So how can I get the lifters full of oil without running the engine to get the proper pre-load on the lifter plungers? Prime it with a drill?

[geezer#99]

Originally Posted by 70STOVEBOLT

So how can I get the lifters full of oil without running the engine to get the proper pre-load on the lifter plungers? Prime it with a drill?

You don't need to!
Watch the plunger on the lifter when you tighten the slack out of them. Then give it a 1/4 turn more.

[70STOVEBOLT]

So tighten the nut until the lifter plunger just starts to move and then go 1/4 turn more?

[DBD]

oil has nothing to do with preload...there is a spring in the lifter that holds up the cup. the old wives tale about soaking lifters is just that. chevy lifters look different than below, but the same basic parts.



no; if the plunger starts to move you've already gone way beyond zero lash and you're only looking for .025 preload or thereabouts...look at a feeler gauge on edge...do you think you can SEE .025??

You're looking to get no slack between the pushrod and the rocker...nothing more. tighten and loosen a couple of times until you get a feel for where there's no slack...you'll know it when you feel it.

[70STOVEBOLT]

So if I stop at the "no slack" point, that should be all I need to do? Every thing that I read says to tighten the nut an additional 1/4 - 1/2 turn after zero lash. Sorry for all the questions, I just don't want any problems with this engine.

[DBD]

Nope, don't stop there - that is zero lash and you want about .025 lash (preload), which is about 1/2 turn.

just take your time and don't make a mystery or a big deal out of it. it needs to be done right, but take a little time to tighten and back off to find that zero lash point - in the end any way you do it you need to get a feel for exactly where that is.

[70STOVEBOLT]

Thanks to all who responded. DBD, I will take your advice and get a feel for it before I button up the engine.