1.6 Rocker Arm Issues

[torq455]

I have those very rockers in a 1.6 roller tip. You will have to go with the 3/8 to 10mm stud. No washers!!!!! You'll have to adjust the lash. It's not a torque to spec and go. I put these in a 94 Z24 3.1 MPFI 2.5 years and almost 20K miles without any problems. You will notice a nice jump in power. For me, they didn't ruin any mileage. Though, with 146K miles, the extra lift has hurt my valve seals due to the little bit of build up on the valve that didn't see the seal. Oh well. Just has a trace of blue if it idles for an extended period when heat soaked.

[1988GTU]

So how did you go about the lash? How many miles did you run it before you reset it?

[1988GTU]

I Did give you the right answer. You can try the stock studs. The only issue is wether or not you get the right preload. No big deal if you don't just convert to 2.8L studs. Once you do you can adjust for proper preload.

Thats all you need to be concerned about.

How would I go about adjusting for proper preload? A feeler gauge of .090?
I think these were a bad idea... My next thread will be probably about "What kinda of valves do I want to replace my bent ones?"

[SappySE107]

Im pretty sure I had a washer under the nut on my rocker arms. I see people saying its a bad idea, so I want to know why its a bad idea.

[1988GTU]

If you can somehow find out what thickness you had, then I will consider the washer idea.... I just would think that the tq spec would be lost with a wash in between everything and a lash value would then be needed for it to be correct preload.

[torq455]

So how did you go about the lash? How many miles did you run it before you reset it?

The right way is to take the the lower intake off. You tighten the nuts while spinning the pushrods until you feel resistance. Then you tighten 1-1/2 turns. I was able to leave the intake on. I just did things the old fasion way: loosen to the point of ticking, then slowly tightening until no ticking, then 1 1/2 turns. Had to grind my ratchet thinner. No problems!!. Same thing for your 1.52's.

[1988GTU]

[1988GTU]

The lower intake needs to come off to do the job properly.

[SappySE107]

Are they working now?

[1988GTU]

Will not know until next week due to poor weather and limited time to work on it. I am about half way through it. I was having trouble trqing the rear studs and lock nuts down due to the lower intake. I guess I'll be replacing my lifters while I am in there.

[1988GTU]

When I goto tighten the rocker arms down, no matter what I do, they give slop. If I tighten down on them more, the pushrod will not spin freely & still have slop. Should the pushrod spin free easily? Should I expect some side to side movement from the rockers? How far should the lifter go down before it's consider fully extended?

[SappySE107]

You are going to have the point where the pushrod will spin but not move up and down. You then tighten it a little more. Someone gave the amount above I think, 3/4 to 1 1/2 turn maybe. Then the pushrod isn't gonna spin freely and the rocker arm should be fairl snug. Its gonna have some wiggle room side to side cause its got a ball and not a roller fulcrum.

[1988GTU]

Does it matter where the lifter position is?
Thanks, well see how it goes.

[torq455]

yes, it should be on the base circle of the lobe of the rocker that you are tightening. hand crank the engine for each one you do.

[geoffinbc]

Check Crane Cams technical section on their site they have a easy to follow writeup on hydraulic lifters. Ignore their preload setting. They say only use 1/2 turn but that is for SAE suds. On metric studs with only 1.0mm thread pitch you need 3/4 to 1 turn minimum.