TurboTommy

I noticed in your original post that you mentioned you changed cams and/or lifters a few times (sometimes used and sometimes new).
I wonder if there would have been a mismatch in wear patterns and something as insignificant as that might have promoted premature wear. Also, to break in the cam to the lifters, and to pump up the lifters, one should run the engine at 2,500 RPMs, at no load, for 15 - 20 mins. You probably did that, I guess.

Thom

I didn't run the engine this way in order to load lifters. It wasn't done either on the previous engines I helped rebuild, and though they were rebuilt with old used cams and new lifters they didn't show that issue at all.

At this point I am thinking the oil check valve may still be faulty. Now that it has been sitting for a day out of the engine, the lack of oil in it seems to be preventing the piston to slide freely.

Paulyy

dirty, metal shavings in it, ect..

Thom

No, oil is clean and doesn't show any suspiscious content.

I will replace the check valve if I can find a used one in good condition.

Thom

Ok, so I sourced a good used valve but it hasn't made any difference.


Would a cracked oil pick up tube show poor oil pressure on the dash?

I'm considering running with no valve at all now, any cons?

marcoturbo

Scary noise.... It sounds like a Diesel engine.

If you remove the valve, shouldn't you prime the engine before running it ?

bebbetufs

This sounds unlikely, but I'll ask anyway.

Was the head shaved at the cam box side as well? If so could it be that the head somehow was shaved at an angle so that the lifters no longer sit at perfect right angles to the valves?

Could the head be out of spec, i.e. too much shaved off the top, leaving too little room between the valves and the cam?

reno808

yeah that does not sound good. i wouldnt keep on doing that. BTW what kind of EMS are you running?

reno808

u should run another cam box to see if that is the issue

Laust Pedersen

The noise pattern is consistent with too low oil pressure to the lifters.

The LR steel/Viton cam housing gasket has a large supply hole and is reusable in case you need to go in there again.

How do your previous cam housing gaskets look? Do they have signs of a leak from the high pressure channel to the inside of the housing (pressure drop)?

Why the blue smoke in the video, is that from a cam housing gasket leak (pressure drop)?

zerMATT951

My lifters get plenty noisy at 3 bar idle pressure, that's when I know I'm a quart or more low and it's time to add...



Typical idle pressure for me is 5 bar cold, 4-4.5 bar hot, but it'll drop down to 3 bar hot when it's past the low mark in the dipstick and it moves around a lot while driving in that condition, but it never goes below 2.5 bar. Of course I add more as soon as that happens... every 3-4 weeks (800-1000 miles).

Thom

The smoke is the burning of oil drops onto (wrapped) headers as I pulled the cam housing off - nothing to worry about.

Here are some pictures of the previous cam gasket.

Oil can apparently make its way between the head and the gasket itself. It looks like oil "pushes" the gasket upwards - the oil valley as embossed on the seal is deformed ALL the way.











Has anyone a picture of the LR seal so that I can figure out how bigger the hole is?

To which extent oil should be able to flow between the gasket and the head?
If I open up the hole in the gasket above the check valve, will that help flow more oil directly above the seal than below?
Are the small additional holes in the gasket supposed to let oil flow back above the gasket and into the oil valley of the cam housing?

Again, what do I risk if I run the engine without the valve?

How do I figure out if there is just not enough oil flow coming from the crankcase if oil pressure as shown on the dash never goes below 4 bar?

Are oil squirters in the 968 block supposed to draw that much oil pressure from the top end?

Sorry for all the questions but this persistant issue is driving me mad!

reno808

that oil dripping on the wrap can cause a fire. you can get a mechanical guage and connect it to the oil pressure sender to insure you have proper oil and spin the engine. i would do that 1st

Thom

Today I tried without the valve.
Oil pressure at idle was 3.5 instead of 5.
Lifters still ticking... Either they won't load or they are beyond reuse...

Not sure what do now...

Laust Pedersen

I have had much more “gasket pushing” into the oil channel without excessive lifter noise, but see no need for oil flow underneath the gasket. This is likely a side-effect of the gasket opening being too small and not clamped all the way around the inlet. The other small gasket holes to the lifters are likely an attempt to bleed off the oil that does go under the gasket. I see two ways to prevent the gasket lift, one is to use a LR gasket (with steel that doesn’t fold) or open up the feed hole and add a high tack dressing around it on the cylinder head side only.
Doing this will make the flow a little better, but I doubt it will solve your problem.

Have you checked for blockage in the oil holes from the oil channel to the lifters?

Is that a bolt into the check-valve area in the last picture in post# 42 (mine doesn’t have that)?
If that is the case, you can use that as a test port for measuring the oil pressure to the lifters with an external gauge.

An oil pressure change from 5 to 3.5 would indicate much more flow, but without a change in lifter noise it is puzzling where it goes.
Btw, my oil pressure is 3.0 at idle when hot and quiet (handpicked) lifters.