Noisy valvetrain after high rev run.

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[Garstang]

After a good run up at 5k revs for sustained period my valve train clacks like lifters have lost load. I pull car over switch off for a minute,  then on and everything OK again until I run high end revs. Oil pressure constant 60psi, sufficient oil in sump, plenty power at higher revs. Running comp cams XE268H, hi rev hyd lifters, stock springs and push rods, stock oil pump. Millars 20W50 oil. Looking for suggestions to cure this.

[Sandy]

Is this the same as what happened before, Gary, when I came round that evening?

And is it happening more often now?

Is it one lifter or more than one? Can you isolate it to a bank or even a cylinder?

[Garstang]

Is this the same as what happened before, Gary, when I came round that evening?

And is it happening more often now?

Is it one lifter or more than one? Can you isolate it to a bank or even a cylinder?

Yes Sandy, same. Only hard driving. Is it one lifter?  Just curious if anyone else has same experience. It disappears when I get back to base, so hard to tell without strip down. Discuss. 

[candy69]

no probe here Gary, not even when been down the strip

[Garstang]

no probe here Gary, not even when been down the strip

I'm talking 10-20 mins up and around 5K Al. Maybe I'm just too hard on my motor.

[candy69]

no probe here Gary, not even when been down the strip

I'm talking 10-20 mins up and around 5K Al. Maybe I'm just too hard on my motor.

perhaps a solid lifter should have been used? or roller? 

[Garstang]

no probe here Gary, not even when been down the strip

I'm talking 10-20 mins up and around 5K Al. Maybe I'm just too hard on my motor.

perhaps a solid lifter should have been used? or roller?  

I had solid lifter in previous engine, didn't have this problem. Is it a hyd lifter issue then, or something else. Would stiffer springs help? Is it oil? Trying to avoid strip down right now as enjoying the drive. Does not seem to be causing any harm.

[candy69]

No expert Gary but as far as i know comp cams sujest the springs for there cams and then shim them also. i had a comp roller cam kit complete when we built mine, came will everything.

[Garstang]

I didn't build the engine, so there maybe something in what you say.

[Cookie]

Hmmm.... sounds odd, could this be lifter "pump-up" or a lifter bottoming out on it's adjustment? Hope you get to the bottom of it matey...!

[Garstang]

Hmmm.... sounds odd, could this be lifter "pump-up" or a lifter bottoming out on it's adjustment? Hope you get to the bottom of it matey...!

Thats what I'm hoping you can tell me Cookie. Can you elaborate on what would cause oddness.

[Cookie]

Wish I had the answer for you matey, but I don't I'm afraid...  
Just throwing possibilities out there...

The only thing I can suggest is to try and trace the noise if possible before it dissipates. When you say "It disappears when I get back to base" do you mean, when you let the engine idle, or after you turn it off at home and it disappears before you take it out on the next outing?

Does the problem occur with the RPM held at 5k for 1-2 minutes? Or only after a prolonged period... like the 10 minutes you've mentioned? Would logically sounds like an oiling related issue if it's the latter possibly?

[Garstang]

Definately happening on the latter at sustained higher rpm. Noise is gone after stopping engine for short time. On normal cruise there is no issue.

[Gee]

does your motor have a standard oil pump or a hi flow jobby, ive been advised to change my oil pump as its a hi flow pump that could cause lack of oil on sustained runs, great if i was draggin the car only but crap for long runs,

or could you have an oil way blockage thats stopping the oil returning to pick up ??

from your latest reply it could be the oil not returning quick enough to get repumped

just a thort

gee

[Dag A]

I guess you have an oil pressure meter.
Check the readings on idle, and at appx 3000 before this happens, while it's there, and after you shut the engine down and restart it.
If the reading is the same, you can look away from the oil.
If readings say that the pressure is lower when knocking is there, thats an indication
of something not good.
My guess is lifters.
Hydraulic lifters are no good for longtime high rpm's, as they have a problem pumping themselves up.
No difference between a flat tappet or roller.
I guess you can imagine what happens to the valve lash?
One trick used is to put more preload to the valve train, meaning tightening the adjusters, but not recommended.
You have to adjust valves for each time you race the engine. Then back when you are finished!
There are different type of lifters, some good, some not, but if this causes the problem, take your hydraulic bumpstick
and send it back where it belonges. I think you know where!!  Get a good mechanical one, and race like hell!
Yes, adjusting valves has to be done, but get a girdle, and look at it as a opportunity to grab a beer and go to the garage!!

[Garstang]

Ah. Good.  I knew if I left this open I would get good response. Sandy you know better than to stray off topic solution. Guess you can't help yourself.  I'll say I held revs at 5K at Knockhill
The oil pressure is steady, there is plenty oil this time, no drop off pressure below 60 psi until below 2K revs apprx
The rockers are roller and there is oil getting up there, but, I'm wondering if windage tray is the problem at high revs. I'll take rocker covers off and check valve lash. My own thoughts point to dodgy lifter thats losing pre load, so maybe a swap out is the better option. Yes. Comp cams also get a bad rap from some windsor boys because of valve train noise at idle caused by fast ramp, but, do deliver good power.
Cheers Lads.

[Mustang-Boss-302]

Gary, I have been watching this thread, and my memory reminded me of a similar problem I had on a 351c I had years ago, my Noise always sounded like lifters and I changed them, the noise came back every now and again, eventually I ripped the engine out for a 460, and whilst it was out I stripped it to find the oil pick up screen was covered in crap, I think the oil was getting through but not fully, when asking a friend who had the same problem, he found different to mine it was a faulty oil filter, his had some sort of a valve in it and it was stopping the flow.
Anyway hope you sort it soon Mate.
Chris.

[mach1 dude]

, but, I'm wondering if windage tray is the problem at high revs.

In what way could the windage tray cause this problem, without windage at sustained high [ ish ] RPMs would be a problem.
You may have a problem with one or two of the lifters being bad but not because they are hydraulic, 5000 RPM is not too high for a hydraulic lifter motor by any means, if you were pulling 6500 RPM it may be different.

[kermit]

it's stethoscope time...

[Tommo32]

Hmm, I would have initially suspected that oil was not returning to the sump quick enough, but as you say the pressure is still fine.

Have you checked the shims/adjustment on the rockers to check the preload is all set right?

There is the possibility that you are just expecting too much of them as other people have suggested.