simple

what can happen and or what would be the most common problem of adjusting rockers to tight?
collapsed lifters, bent or broken pushrods, valves not closing all the way, all of the above?

when setting zero lash, the pushrod should still spin pretty easily but have no up or down travel and at that point is when you do a 1/4 to 1/2 turn more and then tighten the poly lock?
i have a feeling i tightened them too much
i went until the pushrods were semi hard to turn by hand then went a 1/4 turn past that and locked them down, did i do it wrong?

also, when adjusting the rockers with the motor running, where do you place the foil or how do you place the foil?

thanks
Steve

shoebox

I think you answered most of your own questions. You can read here about setting the valves. If you use foil as a barrier with engine running, put it where it will cover the upper part of the rocker that is over the pushrods. That is where oil would squirt out.

LSUxBlake

Rockers too tight can cause all of the things you listed. Often though, if you really have one too tight, the car wont turn over or it will be very sluggish to do so.
Sounds like you did a good job though. They always feel too tight just because you go from a spin to a locked postition where they dont move, but if you felt resistance, went a 1/4 or 1/2 more, you're ok.
As far as foil, I dont know what you're talking about. I assume its to catch the oil, I've always just let the oil spray, it's really not that bad, although you will have to put a little degreaser on your motor after to clean it up. I just find it hard to adjust when it's running, I could never really tell which one was tapping. Someone told me to take a piece of hose about 2 foot long, place one side to your ear, and the other over each rocker, and it makes it easier to hear which one is tapping. In the past, I've always adjusted with the motor off, started it, and if I had any problems, adjusted them while running.

Projectz28

adjusting the rockers too tight can cause all of the things you mentioned. Loss of power, miss, bent pushrods, valve and piston damage...

If you adjusted them so you physically could not "spin" them then youre way too tight. You probably have valves haning open.


Zero lash is the point in which all slack in the valve train has been removed. basically what you want to do is loosen the rocker to the point that you can raise it up and down. then hold it between your fingers and spin it back and forth. slowly tighten the rocker untill you feel the rocker take all the slack out of the valve train and STOP! that is zero lash, You should just feel a slight "drag" on the pushrod from the contact it makes with the lifter and rocker when the rocker tightens up. go 1/4 turn past this point to set the preload of the spring inside the lifter and lock it down. Move on to the next rocker... I hope I am explaining this so you can understand. Its more of a feel thing than it is a visual thing.

If you want to adjust them running, I do 1 side at a time to make it easier. I just use a wet towel to drap over top of the exhaust and car and start it up. I have never used foil. As long as you dont rev it up, at idle there wont be a big mess. Not alot of oil comes out the top end at idle. But it helps to wear saftey glases just incase a drop does shoot out at ya.

simple

thanks, yeah i adjusted them way too tight!
it just makes it much easier when someone explains it like that over all the stuff i have read on here about doing them

im gonna go back over them today and start it up tomorrow

what about the plunger in the lifter, do i have to compensate for that at all since it is hydraulic and they might not have any oil in them now or....

turbo_Z

could always do it with the car running and not worry about that.... granted its not too loud to hear the rockers. as far as zero slack vs zero spin debate goes.. there is maybe a 1/16 turn difference between the 2 from my experience and that surely wouldnt matter.

Projectz28

I think what simple did was literally crank down on the rockers untill he physically put so much pressure on the lifter he literally colapsed the lifter and couldnt move the pushrod at all, not even spin them while in place. Thus forcing the valves open by cranking the rocker down against the bottom of the lifter. In this case there is a HUGE difference between the 2. 1 is zero lash plus preload of the lifter spring. the other is that you have already collapsed the lifter and physically started to open the valve by cranking on the rocker adjustment.

simple, there normally is no compensation for the lifter plunger.... well I guess technically there is, thats what your doing by "setting preload" with your 1/4 -1/2 turn past zero lash. You are making the plunger push up against the pushrod and keeping all the slack out of the valvetriain. If the lifters are in good shape and you have recently run the engine so that they were filled with engine oil pressure, dont worry about them, just set the rockers the right way and go have some fun with the car

ibanez6rg

What's the downfalls of them being a little loose? Can damage occur?

nateh

A little loose isn't too bad. Noisy, but not very damaging. I'd rather hear 'em than smell 'em.

simple

lifters are brand new and the car has not been started yet with the new setup
i can still spin the pushrods just not very easily
i'm heading over to where the car is tonite and gonna loosen all of them and and start over
then readjust when i fire it up with it running

thanks for the help guys

TenaciousZ

What do you do when your about to adjust them on a car that hasn't been run in about 4 weeks?

Projectz28

That depends. if the lifters are new and never been run before you should let them sit in oil overnight, might help a bit. if they are in the engine and it was run 4 weeks ago, dont worry about it. they should retain the oil in them. if you put in a new set and didnt soak them just listen after you start it. Personally I just set them as I already explained and run it. after Ive warmed it up and had it running for a while just listen to them. If I feel they are not just right then just go in a readjust them again. But 99 times out of 100 you shouldnt need to do that. As nateh has said I prefer loose. On my car I set them 1/8 turn past zero lash and call it a day. now you can go too loose, loose to the point that the pushrod will pop out of place at higher rpms if it decided to float a valve. But thats more of a combination of problems 1 being set at or less than zero lash and weak or incorrect valve springs for the setup.

96LT1TX

A little too loose isnt bad, as long as one of the pushrods doesnt get stuck under the lip of your rr's... if that happens you have a bent pushrod... thats how i bent 2 in the past, if you hear a loud tapping turn car off immediatly and check pushrods. I had this happen while adjusting the rr's because one was too loose (not adjusted yet).

TenaciousZ

I was one of the lucky ones, after adjusting the rockers I drove it for a while and noticed a random clacking from the drivers side valve cover. I took the valve cover off and noticed oneo of the rockers was waaay too loose. luckily It the pushrod didn't catch the lip of the rocker.

Valkyn71

I have some Comp Pro mag 1.6 NSA rockers and i have adjusted them around 4 times, and they seem to keep losening up.

I always turn the engine until both valves are all the way shut, then loosen the allen lock thingy, tighten the rocker until the pushrod dosent have any play, then give it half a turn more. then really crank down the lock, while holding the mine part with a wrench.

Anyone have any idea why they wont stay tight?