Adjust Rockers With Valve Covers off & Car Running?

T

TheUser

Active Member
Jul 25, 2003
1,859
1
36
Springfield, MO
#1
Should I adjust the rockers w/ the valve covers off and just put the upper back on... I know the upper has to be on for the car to run. Should I seal the upper? Right now, I have the valve covers and upper on (just got done "adjusting the rockers" - think it's worse now than before :nonono: ), but I didn't seal the gasket, just put the gasket on there. The car runs like crap and I know I have everything hooked up.

Basically, what I'm asking is, should I pull the valve covers and throw the upper back on, start the car and adjust them where they don't make noise (hopefully) and then throw the valve covers back on?
 
#2
TheUser said:
Should I adjust the rockers w/ the valve covers off and just put the upper back on... I know the upper has to be on for the car to run. Should I seal the upper? Right now, I have the valve covers and upper on (just got done "adjusting the rockers" - think it's worse now than before :nonono: ), but I didn't seal the gasket, just put the gasket on there. The car runs like crap and I know I have everything hooked up.

Basically, what I'm asking is, should I pull the valve covers and throw the upper back on, start the car and adjust them where they don't make noise (hopefully) and then throw the valve covers back on?
Click to expand...

Adjusting them with the engine running...hmmm...that sounds a little dangerous don't you think? You didn't specify what the engine was doing. Did you have excessive "clacking" from the roller rockers or was it just running poorly like you had a vacuum leak or something?

Roller rockers make noise due to any one or combination of adjustment issues, "soft" valve springs, "soft" hydraulic lifters, and/or "aggressive" cam profiles. There are a few techniques for adjusting roller rockers, but personally, I have found that adjusting one valve at a time and working your way around the engine from the #1 cylinder to the #8 cylinder works best. It takes a little more time, but there is almost no way to make a mistake. As far as how far to synch them down...don't be surprised if it is upwards of a full turn.

It is a bit time consuming, pulling things apart repeatedly, but my last roller rocker adjustment took me 3 times to get those things to quiet down.
 
#7
I've had the car running more than once with the passenger side valve cover off...oil splashes a little, but not enough to make me worry about getting burnt...It just seems like the easiest way to get them right without pulling it apart 5 times because they're not right. Good point about the upper in the way...should have thought about that. I don't know if it's "excessive noise," I can hear a little clacking, but i'm not sure if that's expected or not..the car is loud and so it's kinda hard to distinguish the noise...thinking about getting a mechanics stethascope(sp?) and see if that helps. The car runs like crap, but that's probably because the upper isn't sealed, just gasket on there w/ no sealent, so prob. still a little leak...the motor shakes like mad and has no power at all...I went to test drive it and decided to put it back up because it wasn't running well at all. I read over Michael Younts method and then went and red ed curtis' method and found "Zero Lash" by tightening the rocker until the pushrod didn't turn and then went another 1/4 turn twice, so half a turn. I did this by using the firing order and getting the the intake valve closed and then waiting until the exhaust valve started to open and backing up a little bit...then tightened both of them down to zero lash and then another half turn and it still sounds like they're making noise...they're not roller rockers, they're stock pedestal mount rockers w/ a B303 cam and hydraulic lifters on GT-40 P heads.
 
#8
The "1/2 turn past zero lash" approach is only for stud mounted rockers. The correct procedure for pedestal mounts has already been described. The problem is that pedestal mount rockers on these cars aren't really adjustable. There's a torque and count the turns procedure for installing them that's designed to let you know whether or not you need to use shims under the rockers or longer pushrods to get the proper geometry. Sounds like you're using the wrong method for your type of rockers.
 
#11
We're assuming that they are stock P pedestal mounts - need to hear from him. IF so, then Mike is right. If not, then I just used 1/4 turn from zero lash, tighten the set screw and another 1/8 turn on the nut to set it up real tight. Started my car and withing 5 minutes of ideling, you can't hear one new lifter or Scorpion rocker.
 
#12
yeah they're stock pedestal mount rockers. Thanks for all of the responses....Guess I got confused. Pulled the valve covers back off and oh my god, nearly all of the bolts were lose and some of the rockers were not even on the pushrods...no wonder it ran like crap, i'm just glad nothing is broken. I got the torque wrench out and rotated and torqued them to 18 lbs after finding 0 lash. Oddly enough, even after finding 0 lash w/ the valves closed, after I rotated the crank and got done w/ all of them..some of the pushrods rotated around...so now i'm doing it again. Also, the first time I did it, some of them hit 1 1/4 turns and 1 1/2 turns, but the 2nd time, they're staying under 1 turn...this is weird. Guess I won't have to shim after all... :shrug:
 
#14
I don't know about the base circle thing :shrug: I'm rotating the crank clockwise and watching the rockers in the firing order. I watch for intake to close and go a little more, where intake is fully closed and exhaust hasn't opened yet and then I tighten the bolt w/ my fingers and most of the time, it's at zero lash (pushrod doesn't rotate) and then I torque them down. The first time, I torqued to 18 lbs; this time i'm going to 21 lbs just to see if that keeps them from getting lose. I've only gotten about half of them done for the 2nd time and I had to put up. Prob. won't be able to finish until Friday. Thought I was gonna end up shimming some of them, but they seem to be fine now, so beats me. Thanks for the advice...any other advice/help is appreciated.
 
#15
if your using roller rockers, loosen the allen bolt a good way,that is used LAST to secure the other nut. The main adjuster nut, 9/16 i think, is the one you should be tightening while spinning the pushrod. Once you feel the pressure being appiled to the pushrod, meaning it just started getting harder to spin, STOP. give them 9/16 nut 1/4 more turn. then lock the allen head nut down.
 
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