engine and drivetrain Problems with valve adjustment

[scestes]

I got the head back for my car a little over a week and a half ago and it sure does look pretty. It's got a 292 cam in it with shrick springs as well, brand new rocker arms and valve guides. Finally got around to getting the rest of the bits bolted together yesterday and today and got to the point where I could hear the beast roar. Roar it did. It was so nice to hear the fruit of the many hours of labor I've put into this. Problem was, there was a tapping noise that was out of place. Popped the valve cover and did a quick valve adjustment. Ready to go right? Wrong. I start the car up again and once again notice a lot of tapping. Pop the valve cover and again, a bunch of the valves are beyond their proper clearance. I've done this 4 times now with the same result. I know what some of you are going to say, "Tighten the bolts duh", well, I tightened the hell out of them and they came loose.

I'm baffled and am looking for guidance from anyone who has experienced this, and explain what they did to remedy it. I don't "think" these shrick springs are anything special, but perhaps they are just too strong for the existing rocker arm engineering and I need performance rocker arms? I don't know...

[ryanOC]

did you strip the bolts for the eccentric lobes?

i usually adjust my valves by hand instead of a feeler gauge

[jerry]

i usually adjust my valves by hand instead of a feeler gauge

huh????

care to elaborate on that?

[scestes]

did you strip the bolts for the eccentric lobes?

Nope, they're not stripped. I've tightened them up pretty tight, but they're not stripped. Even still, even if I've got the gap off a little bit, the lobes are slipping and slipping bad. It doesn't take but a couple of RPMs for the engine to sound like crap.

[ryanOC]

i usually adjust my valves by hand instead of a feeler gauge

huh????

care to elaborate on that?

yeah i just feel the play in the valves and adjust as necessary then torque down

i find i can get a better consistency of all by feel rather than using the feeler gauge. i always had trouble with setting the pinch of the lobe against the gauge, and would often get valves whose adjustments were deviated more than i'd like

[ryanOC]

hate to ask, but are you sure you're adjusting each valve when they're closed? (rocker on cam resting opposite side of lobe)

[scestes]

hate to ask, but are you sure you're adjusting each valve when they're closed? (rocker on cam resting opposite side of lobe)

Yep.

[cj]

Re-do the valve adjustment when they're STONE COLD! Doing a valve adjustment after the motor is just fired up will not give you true readings. The tapping may also be you're timing chain. The tensioner may not be up to pressure yet as you just fired it up.

Cris

[scestes]

Re-do the valve adjustment when they're STONE COLD! Doing a valve adjustment after the motor is just fired up will not give you true readings. The tapping may also be you're timing chain. The tensioner may not be up to pressure yet as you just fired it up.

Hrmmm... Interesting.. I had not thought about the effects of heat on the tension of the bolts. I can tell you for sure though, this is not a false reading. The lobes are actually turning. I'm tightening them down, and they are spinning once I fire the engine.

I will try to redo the adjustment in the morning after the engine is nice and cool. I did let it cool down before I did it last time, but it was not cold. Thanks for the recommendation CJ. Much appreciated.

[TobyB]

odd-

it almost sounds like something's goofy with the eccentrics-

like maybe they're too thin? But then you'd crack the rocker tips....

Hey, here's an idea- are the eccentric pinch bolts bottoming out?

If the nut's running out of thread, that'd cause your symptoms...

I've started lashing valves on TDC for the offending cylinder- the

back of some cams is not always concentric, and at least this way there are

no variables in the process...

huh.

t

[scestes]

odd-

it almost sounds like something's goofy with the eccentrics-

like maybe they're too thin? But then you'd crack the rocker tips....

Hey, here's an idea- are the eccentric pinch bolts bottoming out?

If the nut's running out of thread, that'd cause your symptoms...

Hrmmm.. Too thin.. Something to really think about there Toby. As for running out of thread, very good thought. This was recommended by a friend as well and so we backed off one of the nuts until it was almost off of the bolt, then pushed the washer aside, and it threads all the way into the rocker, so it appears as though there is plenty of thread there for it. Thanks much for the thoughts. I may head to BMW tomorrow and order 8 Eccentrics and pick up a micrometer.

[02jake]

bottoming out sounds about right. do you have the washer installed and are the eccentrics install with the adj. hole on the correct side?

[scestes]

Yea, I checked to make sure they're not bottoming out and I can see I have a lot of thread left as it disappears into the rocker arm. The washer fills some of that area, so I know I've got thread. The adjustment hole is indeed on the top and I've been using it to make my adjustments. Question. Is the surface on both sides the same? Is it flat, or does it have a scuffed side to create more friction on one side that is supposed to face towards the front or back of the car as it sits in the rocker arm? I didn't pull the head apart, so I don't know what they look like out of the car.

[ryanOC]

i believe they're the same on both sides

maybe you could snap a pic of one of the rockers that has gone out of adjustment by itself ?

[scestes]

i believe they're the same on both sides

maybe you could snap a pic of one of the rockers that has gone out of adjustment by itself ?

I'm headed out to do a valve adjustment right now, if they go out of whack again, I'll grab a before and after pic.