My engine began ticking from the port side valve cover at the end of my last run of the season, last fall. The noise was still there when I fired the motor up in the Arizona off season to circulate oil. This past week, I had my mechanic adjust the port side valves and the tick went away. Great! Took the boat out this weekend took it generally easy,ran it full throttle a couple of times (ran great) - and we noticed the ticking was back as we idled at pullout. Damn!

I could use some help on the diagnosis.

More than likely, you have a lifter going bad.

canyonman,

What motor are you talking about? As Griff said it could be a lifter. If your motor has push in rocker arm studs rather than screw in , a stud could be pulling from the head. Also check the pushrods, it is possible that 1 is bending. The pushrod could also be jamming up against its' guide. I would carefully inspect the rocker arms, the rocker balls, pushrods and guides, valve springs,make sure the all the valves are the same height, if you don't see anything, then pull the lifters and check them out.

How is your oil pressure?

BT

The engine is a 502 chevy block marine motor locally built. Roller cam. Hydraulic lifters. The rockers are Crane, gold. It's my first custom built high performance motor, so I am on the learning curve.

Oil pressure was a tick over 40 at idle at start up, well over 40 til the oil gots hot due to fast cruise under way when it settled to a tick over 40 (I use 50 W). Bit under 40 when coming off a fast cruise to idle, like when I hit the no wake zone at pull out. I think that is due to the increased oil temp though? Motor seemed to perform normally.

What would be the progression of things to check out? As I said in my first post, we were able to adjust the ticking out at the shop, but the adjustment didn't hold

Additional bad thoughts. Will a ticking lifter result in a damaged cam? I.E. could I have scored the cam? What problems can an out of adjustment or a collapsed lifter cause?

Any wisdom you all can contribute is all good to me.

Canyonman your problem with the ticking could also be something as simple at a worn nylock nut for the rocker. You did say your mechanic adjusted the valves so he must know which one was the noisey bad boy, so focus your attention on that particular area before you start tearing down the motor.
Good Luck

i agree with griff. sounds like a colapsed lifter and when your mechanic tightened it up he took up the space at idle where there would be slop in it causing it to tick. when you were running, it got pumped up enough from the higher oil pressure and then back to idle, no oil again causeing the tick. if your mechanic tightens down and the lifter pumps up, you could have a valve to piston problem. i don't know your clearance and this is just a shot in the dark but it doesn't sound too bad unless it's a wristpin on your piston.

Sounds like the perfect time to have Bruce build you that 572 you've been thinking about.

i'd put my money on a calpsed lifter, rocker nut, stud

Talked with my mechanic. He said he is confident it is a collapsed lifter. The reason why the tick seemed to "adjust out" was coincidental due to putting fresh 50 weight in at the same time. The new oil, not the adjustment, solved the problem. It comes back if the oil is real hot, such as after my high speed runs over the weekend, or when the oil has been sitting, broken down, as in the off season last year.

Given that the lifter is pumping up, he said it is not worth correcting. Somehow, I am a little concerned about that.

Any opinions?