Datsun Roadster Forum-311s.org

Today's plan of attack is double check the pump, and the rocker assembly. Still no shaving 'source'. I thought maybe timing assembly but the area under it was totally clean. If all those check out, I guess chase the oil flow and assume my noise was sticky valves and the exhaust leak.

Unfortunately I need a new pan gasket and I'd prefer to do the assembly and oiling once. The side seals tore the old one up pretty good and it was leaking out the back. I assume they should be trimmed close to flush?

I too thought the piston looked damaged. Teaches me to trust a peek thru a spark plug hole.

Appreciate everyone weighing in it gives me ideas to check.

Did you always have normal oil pressure on the gauge?

Pump failures are very rare, but I do know of one 1600 pump where the pressure relief valve stuck open….there was pretty mu+h no oil pressure.

Also know of one OP drive gear that broke. (So the pump wasn’t turning). Also no oil pressure.

Fortunately neither was catastrophic since the engine was just idling.

The gauge would have shown no OP.

Yes, oil pressure has always been stellar. Shows 50lbs at idle. I am just curious if I see any shavings in the oil pump.

I am finding some metal crud up in the rocker passages.

https://vimeo.com/593806751

Stock gauge? 50 pounds? Anyone else ever had that much cause it sure isn't me.

The metal could have been left overs from the machine work - some don't clean them out all that well. There were originally Pal nuts on the connecting rods. You should add a heat shield for the header to protect the oil pan gasket. You may want to disassemble and clean the rocker shaft assembly - it may have trash blocking the holes.

spl310 wrote: Sat Aug 28, 2021 12:44 pm The metal could have been left overs from the machine work - some don't clean them out all that well. There were originally Pal nuts on the connecting rods. You should add a heat shield for the header to protect the oil pan gasket. You may want to disassemble and clean the rocker shaft assembly - it may have trash blocking the holes.

How would you shield the header there? Short of bashing it for clearance and ruining the nice ceramic coat I'm not really sure.

Decent amount of crud flushed out of the rocker. None of the actual rockers were blocked that I could find. Confirmed getting fluid down thru them now from the oil passage on the mount.

Well, Nissan had it attach to the exhaust manifold support brace. You will have to get creative. If you look at items 25 and 26 in this image, it hints at it, but they were too lazy to draw it completely.

https://www.carpartsmanual.com/datsun/s ... )/manifold

I’m betting/hoping the rocker shaft is clogged.

Another possibility is it ate the rear cam bushing and that has clogged the passage. That would be rare however.

I’d suggest you put back together the lower end and check for oil flow out of the back of the block. Since the passage in the head is not blocked, it has to be the rocker assembly or no oil flow from the block.

I’m hoping it is just the rocker assembly that is an easy fix.

JT68 wrote: Sat Aug 28, 2021 1:01 pm I’m betting/hoping the rocker shaft is clogged.

Another possibility is it ate the rear cam bushing and that has clogged the passage. That would be rare however.

I’d suggest you put back together the lower end and check for oil flow out of the back of the block. Since the passage in the head is not blocked, it has to be the rocker assembly or no oil flow from the block.

I’m hoping it is just the rocker assembly that is an easy fix.

I sprayed some WD40 down the oil passage on the block and it did drip out off the rear bearing. Not really a definitive test or anything. I kind of want to wait for the new pan gasket to put it back on and fill the bottom end again to test it with the starter but may get impatient and do it anyway.

I did put 20-50 in it which I thought might have caused a restriction or oil pump bypass or something, but so many people run it with no issue. I'll be trying 10-30 next time.

I run 20-50 VR1 without problem.

Curtis wrote: Sat Aug 28, 2021 1:17 pm I run 20-50 VR1 without problem.

nah, 20w50 would not cause an issue.

Considering the amount of crud in the engine, I would be checking the rod bearings while the pan is off... so easy. Fingers crossed for you...

Why am I thinking they didn't thoroughly clean the pan and some crap flushed up in to the engine. This is why I clean it a number of times with lacquer thinner. I had stuff come out from behind the baffle.

Agree with Greg. With high oil pressure and metal shavings suggests the bearings are wearing due to surface to surface contact with the bearing. Do you know if the bearings are undersized? Seems like it…?

Well, wish I had better news. Rod caps were all good torque but found some surprises.

I would say, more a symptom of the metal in the oil than a cause. And also likely not my noise.. Going to check the mains next :/