Top end oiling problem, how to troubleshoot.

Hey folks, a few hundred miles ago I started having some valve train noise, not terrible but noticable. Noise got worse at higer rpm.

After pulling the valve cover I found that the #3 and #4 exhaust cam lobe were discolored and wearing.
The intake lobes didn't look great either but not as bad as the exhaust.

The #1 and #2 cam lobes looked ok.

There was oil in all of the valve pockets, no oil pressure lights.
I pulled a line off after the oil cooler and had good flow there.

So should I start with the head stud on the right side and check flow there? Will I be ok just loosening that outside nut and looking for oil when cranking?

Any thoughts are welcome, thanks

I looked at the cams about 3500 miles ago and there was no visable wear and the noise just started about 300 miles ago.
I assumed I was just due for a valve adjustment.

There is a lot of reflection in your photo and I can't see the wear you are concerned about. I believe that as long as the valve pocket is filled with oil that's all that the cam needs.

Agreed, difficult to assess from the pics but doesn't look bad to me.

Did you check your valve clearances and camchain / tensioner?

Small end rattles -although unusual on these, can be difficult to distinguish from valve noise. Is it better or worse when hot ?


Question for the forum: I know valve shims wear, on the shim over bucket design are the cams harder wearing than the shims?

I assure you, there is wear and discoloration.
It's hard to capture.



Regardless of the pictures, my question is what should my oil flow troubleshooting process be if I suspect the top end being oil starved.
Particularly on the right side.

I would start by inspecting your oil pump. If it's your 750 a ZR7 will fit and is higher volume.

What kind of oil are you using?

1980 kz1000 in my sig.

baldy110 wrote: What kind of oil are you using?

15-40 rotella.



Regardless of the pictures, my question is what should my oil flow troubleshooting process be if I suspect the top end being oil starved.
Particularly on the right side

Tapatalk doesn't show Sig lines.

Has this engine been rebuilt recently?

There was someone that posted that they were having oil flow issues on an engine that was recently rebuilt. He found the oil pump clogged with RTV and silicone from over use and not waiting for it to cure.

Saw a Wheeler Dealer episode where they found the same problem in a Honda S2000 VTEC valve.

I rebuilt the top end about 3500 miles ago, the bottom end doesn't show any signs of tampering.

I didn't use silicone or rtv putting the top end back together. New gaskets, properly cleaned surfaces and zero leaks or seeps in 3500 miles.

Again, good flow coming out of the oil cooler return line with just the starter motor.

Not saying it's not possible that the screen or filter is clogged but my question is what should my oil flow troubleshooting process be if I suspect the top end being oil starved.
Particularly on the right side.

Oil travels up through the head and then to the cam bearings, correct?
Cam lobes are splash lubricated by the oil from the cam bearings before it drains back down?

I'd do a pressure test. It does look like it's wearing through the hard face on the cam. hat kind of cooler setup do you have? If restrictive it can starve the top end of oil. Big end gets oil first then the top end.
teve

I'm using an oil cooler with lager I.D. lines and fittings than what the gpz 1100 used stock.
I'd think that was big enough, maybe its not.

I can bypass the cooler for testing bit the flow seems adequate out of the cooler.
I'm suspecting some sort of blockage in the passages up top somewhere.

My pressure gauge should be here tomorrow.