96 TA

Should I remove my intake to install roller rockers if im going to use the up/down slack method to find zero lash?

Also, I have a stock camshaft, will I need new springs with the 1.6's?

One more question, to set my pre load once i have zero lash should my pre load be a 1/2 or 3/4 turn past zero lash (don't know which one most people go with)? Thanks!

Kevin Blown 95 TA

Don't remove the intake. When you are adjusting the rockers, just tighten the posilocks by hand and you can feel when the slack is gone, then do 1/2 turn more. Just make sure you are on the base circle and it will come out great.

I think new springs are a good idea because yours are 15 years old, but with a stock cam you still aren't going to rev that high, still something to consider while you're in there.

RamAir95TA

Change the valve springs for sure. Running stock springs with 1.6s puts them dangerously close to coil bind.

96 TA

Thanks for the replies! Does coil bind occur at high rpms or through out the power band?

lt1-xjs

For each revolution of the engine, running or not.

96 TA

Does changing out springs require new valve seats, locks ect? Or can i just get springs? I wish i didn't have to get new springs, the install sounds like such a PITA, makes me just want to wait until I get new heads so I can install them while the heads are off.

RamAir95TA

If you go with LT4 springs you can reuse your stock hardware.

raroz28

The install is not bad at all. I have done it while on the car and it's cake. I used a method in which I put air into each cylinder and did it one cylinder at a time. Actually I did it to replace the valve seals, but it's the same procedure.

calaban

Yeah, the Compressed air method is how I changed the valve seals on my IROC as well.

ACE1252

I actually prefer to adjust my rockers with the intake off. That way I can see the rise and fall of the lifter...but I've always had my motor on the stand when doing it.

Finding zero lash....

After moving the crank to the correct position and resting the rocker on top of the pushrod and valve. Screw the polylock down, on the stud, until it just touches the rocker and stops. That is zero lash. No need to screw with moving the pushrod up and down or twisting on it.

Now if we were dealing with the stamped rockers and those nuts that don't twist on the stud easy, then messing with the pushrod to find zero lash might be warranted. Not with polylocks though.....

I used 1/2 turn preload on mine and no problems.

With the piston at top dead center, you can also let the valves rest on the top of the piston rather than using compressed air.

Guest47904

It is advisable to elongate the holes in the head if you are going to use a ratio other than 1.5 However, I had just done it on my truck in May and now have to rebuild or replace the engine due to metal particles. I HIGHLY ADVISE AGAINST CHANGING THE RATIO. (Lifter failure) long story.

With regard to adjusting lash, EO-IC always works for me. If you don't understand it. Google it.

As far as changing the springs.

Valve tool

Do the seals while you're there.

96 TA

^
Yep, exhaust open intake closed. Thats a nice valve tool, ill have to look for one like that. I did just buy a remote starter switch to make the install a little easier so as soon as I have the new springs I should be ready to do this. Whats a easy way to know if a certain piston is at TDC? Reason is ill hold the valves up with compressed air for the majority of the pistons but when I get to the passenger side i know things will get tight and it may be easier to have the piston hold the valve up rather than fight to get the comressed air tool in the spark plug hole.

Thanks for all the replies, you guys are very helpful!

shoebox

You don't need the compressed air if the piston is at TDC. The valve will not go far if it is. Once you determine/confirm that one piston is at TDC, you can use the arrow indicator on the crank pulley as a guide. For every quarter turn of the crank, two pistons will be at TDC. One on the intake stroke and one on the exhaust. The firing order tells you which two (when #1 is at TDC, so is #6 and so on). If your crank hub is still in the factory installed position, the arrow will be at 12 o'clock at 1 and 6 TDC.

This writeup on my website might be something you want to read.

raroz28

I have used this method also but on a 4 cylinder that was easier to work on. I like to be sure I'm at TDC by sticking a screw driver into the spark plug hole to ensure it touches the top of the piston.

All viable methods and all fairly simple enough. I used the same tool shbox has on his site, it wasn't too bad. If you don't have one I got mine at harbor freight for like $10 and it's worked just fine.

ACE1252

I got one of these from Crane(LT1 version) before they closed and it works wonders. I think there are still a few around(ebay).