Im not clueless about cars but im used to LS1's and non adjustable rockers and I recently got some adjustable rockers does any one have a step by step instruction(written for beginers) for setting pre load for stock lifters. What tools i need where to get them and pictures help to want to make sure i get it right before i start up. Thanks.

 

Figure out how much adjustment you get per full turn on your rockers.

Mine happen to be 0.050" per turn.

Set your 0 lash point.

I use the point at which the roller part of the rocker (rolling rockers) does not turn against the valve stem, but doesn't exert any pressure on the valve.

Then dial in your preload.

Another way is to put a dial guage on the roller opposite the valve stem and adjust till the valve just starts to open (dial guage registers movement).
Then "back off" the adjustment for the desired distance.

You can put a feeler guage (set for the desired distance) between the roller and the valve stem and then just stop adjusting when the valve opens.

I don't know what lifters your using, but hydraulics usually have a "pump up" range of 0.020".

Hope that helps.

 

Which rockers? The stud/rocker bolt thread pitch will determine the number of turns, so the brand you have is critical.

 

yella terra adjustables.

and how to i determine how much adjustment i get with full turn? also when i set zero lash i want both valves closed correct?

Sorry for any dumb ?'s just getting to know valvetrain.

 

Use a dial caliper to measure how much the adjuster screw moves when you turn once around.

Yes, you want to set when both valves are closed.

Do a google on setting valves.

Rhoads website has information on setting preload on their lifters, but the same info applies.

 

I can't find anything on the Yella Terra adjustables. Where is the adjustment, at the fulcrum or at the pushrod cup?

 

Question on the both valves closed...I thought I read it is recommended the cam be on its heel per valve. That being, check the intake when exhaust is mid lift, and vice versa? I set mine up using both closed before, so I might try it the mid lift way and see what if any differences.

 

push rod cup i think the yella terra adj. are rather new.

where do i find dial indicator??

 

You can buy one at McMaster-Carr. But, if you know the thread of the adjuster nut you can quickly figure out the preload you are applying. That is the next question, what is the thread? Take out one adjuster nut and see if a hardware store has a matching nut so you can get the thread. 3/8-24 is the likely thread if it is SAE.

 

ok so when i find our thread size how do i figure out preload i am applying??

 

I think you should leave your engine alone, or get someone to help you.

 

Thats why i am here. for people to help. when i started working on cars i knew nothing, through reading on the net and just trying it i have learned a lot and have swaped several motors, trannys, heads, cams. la de la de la. I don't claim to know everything so if there is something im un familiar with I ask for help and i keep asking till i have a grasp on it and i do it. Appreciate all the support

 

Once you get to zero lash, each turn of the adjuster on the pushrod cup will move the pushrod down according to the thread pitch. For example, if the thread is 3/8-24, then the thread pitch is 24 threads per inch. So, one revolution will depress the pushrod 1/24" or 0.04166" or 0.042".

 

ok it is 3/8-24
so next question is how much pre load do i want to shoot for stock lifters??

 

0.080 is a good number that should keep them quiet. They are pretty forgiving, I was running mine at 0.120". So, try two turns past zero lash (about 0.084") and see how quiet it is and how it runs.

If the lifters are not new, you may want to turn them about 1/2 turn at a time waiting and then another 1/2 turn so you don't hold the valve open and the lifter has time to bleed down. This will prevent hitting a valve/piston when you rotate the motor by hand to adjust them all.

Last time I did mine, it took a few hours so plan accordingly. You can do it faster, but I am careful so mishaps don't happen.

 

What happens if they are set too loose? In other words, say you go just 1/2 turn past zero lash which ends up being about .025" preload? What happens when there is not enough preload?