zupmanZ28

I've ran the valves 3 times now, with no change in sound of the tap. I've tried various preloads, 1/4 turn, 1/2 turn, and 2/3 turns, and nothing has changed. i even took one my several old valve covers and cut the top off it so i could run the valves with the engine running. I adjusted each rocker one full turn with the engine running, and still no change in sound. I'm beginning to think i may have collapsed a lifter.

This all started when i took the car out one night, and the valve cover gasket wasn't sitting right, causing a rather massive oil leak. I lost a little over a quart in the time i drove it.

What do you guys think about this? The thing that bugs me is that the car runs absolutely beautiful except that fact that it taps. I put my ear to the valve cover with it running and it seems as though it's clearly coming from under it.

How can i tell if i have a collapsed lifter? All the rockers on the passenger side are getting oil through the pushrod, but i didn't even think to check on the drivers side. Do i need to take them out and test for something?

Eric

PS, heres another thought, could it be that maybe the rockers are hitting the valve cover somewhere? Maybe the rocker is hitting the baffle? When i ran the valves with the engine running one side had the regular valve cover on while the side i was adjusting had the cut ones... The rockers are summit aluminum full rollers (1.6) and the valve covers are GM cast Tall units.

ME Leigh

Its most definitly an exaust leak. Replace the exaust gaskets with copper or alumnium ones and you'll never have a problem again.

SMasterson

I just went through this with a set of Trick Flow heads and a new camshaft install. I also changed to 1.6 Comp Cam Red aluminum Rockers. I'd adjust one and get it to quiet down, start on another and then the one I just finished would start again. So... I ordered another new set of Comp Cam 850-16 Hydraulic roller lifters. My buddy offered to let me use his 1.52/1.6 Pro Magnum rockers. Put everything in and still had a tick on the #6 cylinder, (which is the one that gave me the most trouble when I first installed this cam the the Red aluminum rockers.

To make a long story short... the pushrod was very lightly hitting the bottom of the slot of the guide plate on some cylinders and very hard on the #6 cylinder. It about drove me nuts! My clue was the rocker wasn't oiling as well as the others. I cut the slot in the guide plate about 1/8" deeper and the problem was solved. They've never been quieter in 10,000 miles!

When I go to put my set of 1.6 rockers back in (I bought a set of Pro Magnum 1.6 7/16 because of reading here I shouldn't run aluminum on a street engine I intend to rack up some miles on)I'm sure some more of the guide plates will need clearanced. They actually will move around quite a bit before the rocker stud is tightened down which is probably why I have trouble with some, and not others.

I have the same valve covers as you and there's a lot of clearance under them, (after I removed the baffles.)

Still doesn't explain why it started after fixing the valve cover gasket though but maybe my troubles will help you or someone else in the future.

Anyway, hope this helps.

zupmanZ28

it sounds nothing like an exhuast leak, I should describe the noise as more of a TAP than a TICK.

SMASTERSON, are you using the twisted wedge heads or the normal ones? i have the regular 23* heads. It seems like your theory makes sense, except to say that it wasn't making this noise beforehand. I'm beginning to wonder if maybe the rocker is hitting the baffle.

Now on the other hand, this would make sense if i bent a pushrod, and it was coincidentally at the same time i started dropping oil. Does that make sense?

My theory right now is this: The night it dropped oil, at first it wasn't making the noise. I thought the cover was loose so i tightened it down quite a bit, which basically eliminated the spacer effect of the gasket. I don't know exactly when the tap started, but i know it was after i tightened. Now the gasket i replaced the thick cork one with was a rather thin rubber one, maybe a third the hieght of the cork one. I think that since the cover is sitting lower, it may be hitting the baffle or the sides somewhere. does that make any sense? or am i barking up the wrong tree.


Eric

spartyon

if it wasnt makind the noise before then i highly doubt its hitting the valve covers unless u changed them and noticed a difference. if they are the same covers that shouldnt be your problem. i am having a hell of a timing setting the preload on mine. but it should be alot easier once i have the engine running to set them. collapsed lifter would be the only other thing i can think of.

zupmanZ28

so i should be looking more at like a bent pushrod or a bad lifter then.

i'll tear that side down Tues, or maybe later on tonight.

Any other possibilites?

Eric

zupmanZ28

popped the valve cover and found that the back of one of the rockers had a worn spot as though it had been rubbing something. I started with no valve cover and there was no noise. I'm assuming it's hitting these little tab like things on the underside of the cover. Or maybe the side of the baffle...

Now i opened a whole new can of worms. When i started it ZERO oil came up through ANY of the pushrods. i let it run for a good 20 seconds, witha couple small revs inbetween how long should it take to get oil onto the valves? i thought is was rather instantaneous.

zupmanZ28

the cover:

89RsPower!

not sure of an actual time or anything but yeah its normally almost instantanious like a sec or 2 after the engine starts...

Marshall89ws6

describe your bottom end..... it's most likely not this but u want to make sure it's not... my buddy put together a 302 for his mustang with a recon (stock) bottom end... the valve releifs weren't big enuf for the valves and there was some (very little but enuf to notice) piston-valve contact. when we took it apart you could see where it was hitting but you had to look very closely.

zupmanZ28

i know it's not that, since the car has run for a few hundred miles before this started happening. I KNow it has nothing to with clearances, or geometry. either a part has failed somewhere, or something is rubbing.

I've pretty much got the noise situation covered, now i'm more concerned about the fact that i didn't see oil coming through the rocker...

Eric

zupmanZ28

alright i started it again, and fast idled for about 10 seconds. Oil started seeping up through so i guess that problem is solved


EDIT: yep problem solved. With no valve covers on either side the motor is silent, and all rockers are getting oil. Now all i gotta do is clearance the valve cover and put thick gaskets in and i'm set. Thanks for everyones help, i appreciate it.

Eric

99Hawk120

My motor must have oil restrictors or something in the top end, because it takes forever and NEVER has much oil up there.

Oh well... more available for the bearings...