Setting valve lash

[Wes]

Need some help on this one.

CompCams tells me this

Hydraulic Flat Tappet and Hydraulic Roller Camshaft​

​

: First turn the engine in the normal direction
of rotation. Start with cylinder number one (1). When the exhaust valve begins to move, adjust the
intake valve to zero lash plus an additional ½ turn more. Rotate the engine over again until the intake
valve reaches maximum lift and is almost all the way back down. Then set the exhaust valve to zero
lash plus ½ turn. Adjust the valves on each cylinder in this manner until all valves are adjusted.

My question is, how do I know when a valve is "almost all the way down".
I think there would be a little more precision to it than this.

Any help would be greatly appreciated.
Wes​

 

[Petzschler]

smallblock chevy adjustment guidelines.. kinda one size fits all thing. attention CompCams: NOT.
anyways, I just put the lifter on the heel of the cam lobe, and crank her down 1/2 turn
from zero lash. a good way to determine zero lash is to spin the pushrod lightly until it stops.
NOTE: make sure there are no more then 1-1 1/2 threads showing out the bottom of the rocker.
if theirs more then that, bad things will happen. i assume you bought the complete set. so u should be ok.
If you made your own, you will need longer pushrods. anyways, hope this helps yah.

 

[Wes]

The cam and rockers are new, the pushrods are the originals from the 383. The shop checked them out and said they were fine, do I need to get new longer ones?

The cam was CompCams XE268H
The roller rockers are 1.6 made by Shanon's Engineering

 

[Petzschler]

The cam and rockers are new, the pushrods are the originals from the 383. The shop checked them out and said they were fine, do I need to get new longer ones?

The cam was CompCams XE268H
The roller rockers are 1.6 made by Shanon's Engineering

they should be if memory serves mech.rocker/hyd.cam is 8.375" long for B-engines. also i think the stock hydraulic ones are 8.593" long.
so my mistake.. you'll need 0.218" shorter ones from stock.

 

[Wes]

Thanks 360!

 

[fishy68]

Here's a Mopar chart that shows the valve adjustment sequence.

 

[Wes]

Here's a Mopar chart that shows the valve adjustment sequence.

I saw that Fishy, but what am I using as a gauge for the 90 rotation? The harmonic balancer?

And is this for zero lash?

Thanks for the help guys!
Wes

 

[fishy68]

I saw that Fishy, but what am I using as a gauge for the 90 rotation? The harmonic balancer?

And is this for zero lash?

Thanks for the help guys!
Wes

Yeah I use the marks on the balancer. I'm not sure all of them have marks like mine that has them every 90 degrees though. If yours has them that'll work fine. If yours don't have marks every 90 degrees you can measure it out with a cloth tape measure into 1/4ths starting at tdc. You can set the lash to what ever you want. Zero for hydraulics or whatever for solids. It don't matter if it's a hyd. or solid you set them the same. Just the lash spec is different.

 

[Longgone]

Need some help on this one.

CompCams tells me this

Hydraulic Flat Tappet and Hydraulic Roller Camshaft​

​

: First turn the engine in the normal direction
of rotation. Start with cylinder number one (1). When the exhaust valve begins to move, adjust the
intake valve to zero lash plus an additional ½ turn more. Rotate the engine over again until the intake
valve reaches maximum lift and is almost all the way back down. Then set the exhaust valve to zero
lash plus ½ turn. Adjust the valves on each cylinder in this manner until all valves are adjusted.

My question is, how do I know when a valve is "almost all the way down".
I think there would be a little more precision to it than this.

Any help would be greatly appreciated.
Wes​

Watch the rocker arm compress the valve spring and you can tell what position (almost all the way down) the valve is in.

 

[Petzschler]

why make it harder then it needs to be? 1 1/8" socket on a half inch drive rachet, long handle, turn over
clockwise and do one cylinder ata time. we all know when the valve closes. saves from jumping around all
over the place.

 

[fishy68]

why make it harder then it needs to be? 1 1/8" socket on a half inch drive rachet, long handle, turn over
clockwise and do one cylinder ata time. we all know when the valve closes. saves from jumping around all
over the place.

I'm assuming your refering to the chart. I agree it seems to jump all over but at least you can do it in one revolution of the engine. If you do it one cylinder at a time it takes 2 revolutions. Plus doing it by the chart guarantees you your at the bottom of the lobe so for the less experienced it's easier. What may seem harder to one may seem easier to another. For 20+ yrs. I did it the old way. Now I use the chart and get it done in about half the time.