Had just assumed you were into the rods, even though you clearly are into the mains. My mistake! It's the RODS I would change without a second thought. Being they are prone to fail and pretty easy and affordable. I might just button up those mains and change the rod inserts since I'm there.

 

That would explain why you still have good oil pressure too. Mains really have an affect on pressure. Rods have little since they are not fully pressurized like the mains and cam bearings are.

 

i disagree. my friend had one (lower half) of a rod bearing that was bad. first indication of a problem was VERY low oil pressure.

 

X2^ Every bearing matters. I lay awake at night wondering if a rod there doesn't work a little like a centrifugal pump. At 3K, the oil in that passage out to the bearing has got to be "headen out".

I think there and the cam might be the first places pressure might be lost.

 

Rod bearings (or any bearing) has an effect on pressure but rod bearings have the least. By design the supply of oil to the rods is intermittent as the oil holes on the drilled crankshaft main journals get a "shot" of oil when the holes line up with each revolution.

 

My rods were the 'worst' of the batch when I was dropping to '0' at operating temp idle.

I replaced all bearings so I couldn't tell you if just changing the rods would have helped.

As far as clearance, if you don't have a mic, try the plastigauge to see if you're even in the ball park. Cheap as wax, because it's cheap wax.

 

Ah, understood. I had never put that together. Much thanks from A big, (not so bad)(normally), Don. An interesting dynamic there then. Then with the centrifugal, (or centripetal), (centrifugal holds in), force there, might be whatever goes out the 'galley?" might mostly go out..regardless. MMMM.

Anyway I've slapped rod inserts in a few engines simply because I could reach them!

 

My oil pressure is poor when hot, it is what started this whole dissection. I have however found an extremely clogged oil pickup screen to the point that I wonder how andy oil got through at all.

 

"All bearings" as in Rods and Mains, or did you do camshaft as well?

 

How low? Pressure is lower at hot idle because:
1. the oil is thinner
2. with the lower rpm the volume output of the pump goes way down
and has a harder time keeping up with internal leakage (bearing clearances)

With a clogged up pickup screen bullet#2 would decrease output even more!

 

Hi bigbadon,

We've talked before concerning my low oil pressure. I am currently replacing my cylinder head (and intake manifold since I found it was cracked when I removed it to get to head...maybe the source of funny whistle) as well as playing down below and checking out oil pump and bearings.

Hot idle (about 650 rpm) is anywhere from 3 to 12. At 2000 rpm I'm roughly 20 psi. I will also have to replace rockers and pivots due to them being scored, fortunately the junk yard head had ones in decent condition.

 

I have similar pressure readings on my 2004 SE with a 2000 salvage motor. Since your bearings have checked out to be good it is possible one or more cam bearing could be the issue but I would be more suspect of that inlet screen. You can't do anything about the cam bearings without pulling the engine so I would try a new pump and screen first.
Glycol from a cracked head will destroy bearings but it will also create sludge....hopefully for you it is the latter. Another thing, some coolants are more destructive than others. The old conventional is the worst because it contains silicates. The "any make,any model" is silicate free and the G-05 has some silicates. But all of them will create sludge when mixed with oil. From the appearance of your bearings I would think your OK. A insert that was black or had copper showing would be a sign of coolant damage.

 

Did you find much in the pan? Again that was sorry of me not to take a better look at your photos. Got to be curious where all that stuff in the screen came from. Rocker pivots...hope you get after those rod inserts...as 364K points out they are still suspect.

 

Yeah, I'll pop a rod bearing tonight and take a look at it. Thanks everyone!

 

So removed the #4 rod bearing tonight. Looked in pretty good shape. The bad thing was I pulled the lifters. Number 4 intake was VERY concave (it was not contacting the rocker well and I was hoping the lifter was collapsed) haven't measure the lift on the cam lobe where it was yet.

Odds are now though that I am not replacing any bearings. I will check timing chain. Replace rms, replace oil pickup tube, check plate bolts and put her back together.

On top I'll drop in at least one, most likely all new lifters. At this point I figure why bother with any bearings, they are score but within spec, if anything I'll be rebuilding due to the need to replace the cam and will just do all the bearings at once if that happens.

BTW, the rod bearings did have "STD" stamped on them

THANKS EVERYONE !!!!!