HELP ENGINE PRO's: Rebuilt Engine & Oil Pressure

[Bambikiller240]

Just completed the installation if my rebuilt L24 into Bambikiller and I seem to have a slight problem. I attempted to prime the fuel and oil system by spinning the engine with the starter motor while the ignition is disconnected as I have always done, but I'm not getting any significant reading on the oil pressure guage. Also, when I pull the valve cover it doesn't seem that any oil is squirting onto the cam from the cam oiler tube. Everything else seems fine.

Any advice from you experienced engine guys will be appreciated. Thank you!!

[2ManyZs]

You didn't forget to install the oil pump drive spindle did you?:cross-eye Just kidding...

Did you pull the distributor cap just to be sure it's turning? That would be one way to tell if the maybe the drive gear isn't engaged on the spiral gear.. but doubt it would have bolted up OK if it wasn't engaged...

Did you do anything to the oil pump? Some people will put a little vasaline(sp?) over the screen on the pickup so that the pump will draw a vacuum and pull the oil up quicker....

If you aren't getting any oil up top it almost has to be the pump or the spray bar. But it could be something like the pressure relief valve in the oil filter mount...

Did you do anything with the soft plug in the front face of the block on the oil gallery to the left of the cam chain tensioner? Or the one in the back of the block?

Last but not least.. and this may sound silly.. are you sure you put 5 quarts of oil in the pan? If it's a quart low it might take a while before it picks up...

[Zs-ondabrain]

I'm not a serious pro but my first thing to check would be the oil pump rod and w/ the distributor cap off I'd check to see if the rotor is turning

if the locking pin on the crank is slipping, the oil pump and the distributor wont move

hey, it's a shot in the dark, even for me, but what the heck

and I hate to even mention the other possabilities,......

[Zedrally]

I remember reading that the oil pump should be primed before fitting.

[Zs-ondabrain]

one other thing I thought of was ....

the oil pump pumps at idle to 7000+ rpm

and it may take awhile for the oil to get there

oil in the pan??

plugged spraybar??

bad oil filter???

keep guessing.

[2ManyZs]

The oil pump should be primed.. but the only real way to do that right it to dissasemble the pump and put some light oil or assembly lube on the rotors of the pump.

Another thing to consider would be the oil pump pressure relief valve...

I'm just thinking of the obvious "slap yer forehead" kinda things we sometimes forget...

[Bambikiller240]

I did add 5 qts of oil to the pan, The oil pump and spray bar are brand new OEM Nissan units. The oil pump drive spindle is installed and turning and thus the distributor (rotor) spins as it should. (verified visually) Oil filter is a brand new K&N.

Engine (short block) was professionally rebuilt and the main oil galley plugs at front and rear of the block were removed and replaced by the machine shop.

The engine is rotating via the starter motor at a relatively low RPM compared to even idle speed. Even in this circumstance I would expect to see oil squirting out of the oil spray bar AND see oil pressure on the guage, right?

I didn't "prime" the new oil pump before installation, guess I now get to drop the front sway bar off the car and pull the oil pump in order to disassemble it and check it's pressure relief valve and to prime it.

Carl

CRAP. I HATE DOING THINGS TWICE!

PS: Not arguing the point, Keith; but since the oil pick up screen should be immersed in the 5 qts of oil inside the pan.......I don't see how vaseline on the screen can create any more of a vacuum than what would already exist with the screen submerged in oil. Too late for me to do that anyway (without pulling the whole engine), since it is already installed in the car.

[Bambikiller240]

Ok, We got Oil Pressure, Engine Fired and all appears well!

I pulled the Oil Pump and disassembled it. I coated the rotor and sleeve that it "rotates" in with some wheel bearing grease, then re-assembled the pump. Lastly, I filled the pump with oil and re-installed. Only took about 20-25 seconds of spinning the motor on the starter before oil was squirting out of the cam oiler tube ports and the oil guage was reading 30-40 psi. Got better pressure as soon as I fired the motor up.

Someone needs to tell the publisher of the "How to Rebuild Datsun/Nissan Engines" book to at least mention how critical it is to PRIME THE FRICK'IN OIL PUMP in the next printing of this otherwise very useful book. Sheesh, what a "minor" bit of information to leave out! :stupid:

[LanceM]

Good deal that is all that it was.

In my pre z life (chevy, pontiac) we always spun the pump useing a drill and an old distributor shaft to get things primed along with we always packed the pump with light grease (vasileane?) to be sure it would prime.

I'm sure the writer didn't mean to leave it out, sometimes there are just things you take for granted that everyone knows, even though they don't!

At least on a Z you don't have to drop the pan to get to the pump!!