LS-5 Valve cover dripper issue

[Tom L.]

Last fall I had a minor tap on the drivers side of the engine, middle of the valve cover. After a long winter I finally took the cover off today to see what was goin on. To my surprise I found two of the drippers broken off and sitting on the head, one against a spring (should have taken a pic). Haven't checked the rocker adjustment yet but at this point I'm "assuming" that the tap was the piece of dripper leaning on the spring. I looked for interference contact on the two rockers but saw nothing. After removing the gasket I placed the cover on the head with no gasket, no indication of any interference. Any ideas? Anyone ever have a dripper break off? Thanks!



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[Joe L.]

Re: LS-5 Valve cover dripper issue

Last fall I had a minor tap on the drivers side of the engine, middle of the valve cover. After a long winter I finally took the cover off today to see what was goin on. To my surprise I found two of the drippers broken off and sitting on the head, one against a spring (should have taken a pic). Haven't checked the rocker adjustment yet but at this point I'm "assuming" that the tap was the piece of dripper leaning on the spring. I looked for interference contact on the two rockers but saw nothing. After removing the gasket I placed the cover on the head with no gasket, no indication of any interference. Any ideas? Anyone ever have a dripper break off? Thanks!



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Tom-------


I've never seen or heard of this problem. However, the only possible way that I could see it happening is by interference between the dripper and the rocker arm. It's just not something I see occurring "spontaneously" or from any sort of metal "fatigue".

[Mark E.]

Re: LS-5 Valve cover dripper issue

Stock rocker arms?

Did you rotate the engine while checking for interference?

[Tom L.]

Re: LS-5 Valve cover dripper issue

Did not have time to rotate the engine OR check valve adjustment. As I said I put the cover on without the gasket and it sits flat on the rails of the head.

Honestly I just can't see how movement of the rockers (BTW, Roller "tip" type for 15+ years w/ no issues) would cause interference. I measured, the drippers sit directly over the adjustment nut where there is no movement. Very strange... Will get after it this weekend.

[Justin S.]

Re: LS-5 Valve cover dripper issue

Tom,
Did you have the covers off prior to last fall?
There's another thread regarding installing the covers "upside down " which might misalign the drippers.

[Mike E.]

Re: LS-5 Valve cover dripper issue

Tom,
Did you have the covers off prior to last fall?
There's another thread regarding installing the covers "upside down " which might misalign the drippers.

[Mark E.]

Re: LS-5 Valve cover dripper issue

I'm grasping at straws here...

Is the top of the valve cover bent down or warped a bit causing less clearance?

[Tom L.]

Re: LS-5 Valve cover dripper issue

Nothing obvious, didn't lay a straight edge on it though. Something not so obvious that I didn't note is that both broken tabs are from Exhaust valves.

[Mark E.]

Re: LS-5 Valve cover dripper issue

Rocker arm studs loose or higher than normal causing the rocker arm to sit too high?

[Joe L.]

Re: LS-5 Valve cover dripper issue

Did not have time to rotate the engine OR check valve adjustment. As I said I put the cover on without the gasket and it sits flat on the rails of the head.

Honestly I just can't see how movement of the rockers (BTW, Roller "tip" type for 15+ years w/ no issues) would cause interference. I measured, the drippers sit directly over the adjustment nut where there is no movement. Very strange... Will get after it this weekend.

Tom------


The plot thickens. Are you using stock-type, prevailing torque lock-nuts or poly-locks? Are your rocker studs stock or aftermarket?

[Tom L.]

Re: LS-5 Valve cover dripper issue

Joe, to answer your questions, all stock except for the rockers which came on the engine. I had to have the heads done about 7-8 years ago, guides had crapped out, done, it used oil like gasoline. Rockers were fine so I re-used them.

An update... I cranked the engine enough to pump the lifters up (enough?) and put the covers on while it cranked I held my hand in the area of the tap. Easier to isolate without it actually running. Apparently the tap I heard, and felt last fall had eluded me (or I was in denial) had been there for a while.

History.. About 4-5 years ago I was able to purchase a set of original '72 covers, not easy. That's when these went on. The covers I took off also had drippers, they're undamaged (even one on to see if there was a tap, nothing). I suspect that the two broken drippers in the pic posted were knocked off early on (???).

Can't imagine that the rocker nuts backed off with new nuts (on old studs) but I guess it's possible. Don't have time to get adjustments checked until the weekend. Thoughts?

[Mark M.]

Re: LS-5 Valve cover dripper issue

I agree with Mark to check the stud height. And as Joe asked are all parts stock. Original cork gaskets are around 1/4" thick and as they age and the bolts get tightened to stop leaks, the gaskets can get squeezed thinner. Since you said both are exhaust, I would check the ball and rocker seats condition as exhaust runs hotter and an issue may lurk there. The seating surfaces should be shiny. I've seen broken BB drippers but never had an engine with the issue. Hope I can still say that Saturday when I start 69 427 with restored original covers going back on.

[Tom L.]

Re: LS-5 Valve cover dripper issue

Just an update on this. After checking the rocker adjustment and finding it was fine I looked REAL close at the rockers, broken drippers and the third that I thought was making my tapping noise. There was NO evidence on the rockers themselves of interference, probably because the material is harder and they were lubricated quite well.

Close examination of the two broken drippers, with a magnifying glass, showed a tiny mark on the left side of each. Knowing what I was looking for i looked at the third intact dripper, it showed an even smaller mark on the left side of it. Guess the first two broke fairly quickly after initially installing the covers a while back and I guess I didn't pay close attention to, or was in denial about, the slight tapping noise I heard.

I looked closely at pics of stock rockers (Don't have any on hand to look at) and the ones on my car (pictured below). it "appears" that the sides of the rockers, closer to the tip, are a tad higher than stock resulting in interference. To correct this I just bent the tip of the dripper slightly to the right, put it together to check and the tap was gone. An annoying problem with a simple fix, thanks for all the chimed in.

[Mark E.]

Re: LS-5 Valve cover dripper issue

Thanks for letting us know how this mystery was solved.

I know they have their place with high-RPM engines, but I've shied away from multi-piece rockers. Although not likely, I worry about the tip failing and all those little bits and roller bearings going into the engine. Plus OEM style rockers mirror Chevy's design philosophy: simple, inexpensive, reliable.