Can oil pressure be manually tested in a fresh rebuild before engine startup?

[Jeffu]

I have a question that I can't seem to get an answer from anyone, so I am bringing it to the forum.

My question: Can a person manually, "by hand," turn the crank enough to generate any type of oil pressure gauge reading on a new rebuild? This of course is to try and verify oil pressure with the motor outside of the car and with an aux pressure gauge hooked up to the oil pressure sending unit port. I began by filling the motor up with break in motor oil by first pumping 2 quarts through the oil pressure sending unit passage way. This way I felt that I would be sure to push enough oil throughout the various passageways. Once I got 2 quarts in, I hooked up a manual oil pressure gauge directly to the sending unit port. I then filled the engine completely up with the remaining quarts of oil. With the motor suspended via the engine hoist, I leveled the motor out horizontally. I then placed a 2' breaker bar w/socket on the crank pull and slowly began turning the motor clockwise. I proceeded to turn the crank for about 50 turns at a fairly steady pace. However, the needle on the oil pressure gauge did not budge. At least I figured I would at least make the needle slightly bounce up and down, but nothing? Is this to be expected? Do I simply not have enough force turning the crank to pressurize the system and move the oil pressure needle gauge? I was doing this to more or less make sure the oil lubrication system was fully pressurized before dropping the motor back into the car and attempt to turn the motor over for the first time. Like I mentioned this is a complete rebuild with new cams so I wanted to ensure a smooth a possible initial start.

If anyone can let me know if I should have observed some type of movement on my oil pressure gauge or not?? I would greatly appreciate the feedback!

19806

[Bitsyncmaster]

My guess would be no. You will not get any pressure turning the crank by hand. You may be able to read some pressure with the starter turning the engine (leave the spark plugs out). Most any type of pump is not designed to seal the fuild flows with speeds that low.

[Josh]

Good lord that engine is spotless!

[Nuclearbacon]

Most starters won't turn the engine over fast enough to produce the pressure needed to kill the low oil pressure idiot light (comes on at 5psi in our cars). On all my Subaru engine builds, I'll pull the fuel pump fuse and crank the engine over, getting oil flowing through the engine before the initial fire. With an engine build, the best thing you can do during assembly is putting moly grease (or the equivalent of engine assembly lube you used) in good amounts on all surfaces like bearings, etc. By doing this, you can get a solid 10 seconds of run time, before oil pressure and destruction becomes an issue. (The engine will be lubricated by the grease if the oil pump doesn't do what its supposed to, or some other issue)

My $0.02

[David T]

If you hook a starter up you should see *some* pressure, just not a whole lot. You will never see any pressure by turning it over by hand. What some builders do after building a motor is to hook up an external electric auxiliary oil pump and run it to get oil all over the motor during an initial start. IMHO a bit of overkill for a PRV. If you assembled it with assembly lube that should protect the parts till you get oil pressure up. For an initial oil fill I like Marvel Mystery Oil to help break in the parts. Dump after 500 miles and examine it with a magnet and cut open the oil filter. If you are OK then you should be fine for a long time. Recheck valve lash too after around 1,000 miles. Cams have a particular break-in procedure if you have new ones. Typically once the motor gets started it is run at 2,000 RPM's for 20 minutes. Josh may have a more specific method of break-in (this one is generic).
David Teitelbaum

[Jeffu]

Most any type of pump is not designed to seal the fuild flows with speeds that low.

That was kind of my thinking. As we all know these motors are not cheap to rebuild. So, I wanted to bounce the question off of you guys to make sure I have my "T's" crossed and "I's" dotted. thanks Dave

[Jeffu]

Good lord that engine is spotless!

Thank you Sir! :)

[Jeffu]

Most starters won't turn the engine over fast enough to produce the pressure needed to kill the low oil pressure idiot light (comes on at 5psi in our cars). On all my Subaru engine builds, I'll pull the fuel pump fuse and crank the engine over, getting oil flowing through the engine before the initial fire. With an engine build, the best thing you can do during assembly is putting moly grease (or the equivalent of engine assembly lube you used) in good amounts on all surfaces like bearings, etc. By doing this, you can get a solid 10 seconds of run time, before oil pressure and destruction becomes an issue. (The engine will be lubricated by the grease if the oil pump doesn't do what its supposed to, or some other issue)

My $0.02

Thanks for your input.
Yes, generous amounts of assembly lube was used so I should be good to go.

[Jeffu]

If you hook a starter up you should see *some* pressure, just not a whole lot. You will never see any pressure by turning it over by hand. What some builders do after building a motor is to hook up an external electric auxiliary oil pump and run it to get oil all over the motor during an initial start. IMHO a bit of overkill for a PRV. If you assembled it with assembly lube that should protect the parts till you get oil pressure up. For an initial oil fill I like Marvel Mystery Oil to help break in the parts. Dump after 500 miles and examine it with a magnet and cut open the oil filter. If you are OK then you should be fine for a long time. Recheck valve lash too after around 1,000 miles. Cams have a particular break-in procedure if you have new ones. Typically once the motor gets started it is run at 2,000 RPM's for 20 minutes. Josh may have a more specific method of break-in (this one is generic).
David Teitelbaum

Yes, I have read up well on the initial break in procedure for new cams. I plan on priming and checking all fuel lines and injectors (all new lines and injectors btw), adequate coolant level and I should be set to go. I know enough that once that baby fires up for the first time I will let it rock and roll for at least 20 mins unless there is something so significantly wrong or dangerous that I am forced to shut it down. Thanks Dave.

[David T]

Forgot to mention, On older Chryslers you would pull out the distributor and stick a 2' hex shaft directly into the oil pump. Hook an electric drill to it and then crank the motor over with the starter to prime all of the lifters before starting it up. Then you would have to retime and install the distributor but at least you knew you would have good oil pressure (you didn't forget a gallery plug or something stupid!) Common error was to forget to put the plug into the block at the back end of the camshaft. Makes a BIG mess and if you had the tranny on a LOT of extra work. Not sure how you could prime a PRV motor. You can always do it externally.
David Teitelbaum

[TTait]

Is that water pump pulley going to fit okay?

[Jeffu]

you would pull out the distributor and stick a 2' hex shaft directly into the oil pump. Hook an electric drill to it and then crank the motor over with the starter to prime all of the lifters before starting it up. David Teitelbaum

Yes, I have heard of that. Just wish it would be that easy on these motors. :thumbup2:

[Jeffu]

Is that water pump pulley going to fit okay?

Oh yeah. It was on there before the rebuild. It's the water pump with the 4 bolt-on pulley. With it being painted and the angle of the picture it makes it appear larger and "more in your face" than it really is...lol

[dmc6960]

You have engine assembly moly lube on everything, right? That'll keep everything just fine for several seconds on your first startup. When I did this I primed the oil pump with a baby-medicine syringe through the oil filter port. Started the engine up for the first time and had good pressure in nearly the same amount of time as an oil change.

You'll be fine.

[DMCMW Dave]

Before you put the timing cover on, you can manually spin the oil pump. Messy but it works. And a very good idea to prime the pump and make sure the pickup is all installed properly.