Help with my 82 project

I’ve gotten a lot of great help here and now I definitely need some. Newly rebuilt engine. First fire up, I use a rod on the pump to pre-oil the engine and it builds some pressure. Not a lot, but up off the L on the gauge and I also have a manual gauge I added and I can see the oil pushing in the clear tube. Finally, after setting the timing several times, I fire it up. Once the oil pressure needle moves we run it up to around 2000 rpm and the pressure goes to about 1/4 gauge. After about five minutes i notice the engine noise increasing and look in at the gauges. The oil pressure has gone to almost zero. Scared I’m fixing to ruin it I shut it down.
So....I pull the distributor and put the drill back on the pump and it will not pump any pressure on the gauge. When I stop I can hear oil running back down in the pan. I also took off the hose at the sending unit and it does pump out of there but not enough to even make the gauge wiggle. Any advice is very much appreciated. I’m about ready to throw in the towel. Thanks

This is a 351w

It doesn't sound good...

Can you tell us more about the rebuild and what work was done? And what oil you used?

On a new cold engine with cold oil (By cold, ambient temps) you should have had oil pressure that pushed the gauge past the middle, up between 50-60 psi, maybe even a bit higher.

Just past the "L" on the gauge wouldn't be enough pressure to do a 2000RPM break-in.

Danny,

I agree with Cory that that doesn't sound good.

What kind of assembly lube did you use?
I usually spin the pump until I see oil pouring from all rockers before I put on the valve covers and fire it up to break in the cam.

I had the block went through at machine shop,  valve job with new valve seals.  Reused pistons and rods, new rings, rod bearings, cam bearings, can, lifters, reused push rods. Used comp can lubu on the can and Lucas assembly lube very liberaly on everything else. Napa 30w oil with a bottle of Lucas zinc break in oil.

No oil pressure on a rebuild? Not good. I'd be calling the machine shop.  

That all sounds good 👍

So did they assemble the short block?
If you did, did you throughly clean out all the oil and coolant passages?

I use Brad Penn for breakin oil, but that shouldn't make a difference if you added ZDDP.

Machine shop cleaned, inspected, miked, and chased all bolt holes. I picked it up in a engine bag. I built it and did no extra cleaning.

Dk46 wrote

Machine shop cleaned, inspected, miked, and chased all bolt holes. I picked it up in a engine bag. I built it and did no extra cleaning.

I bet that is where the issue is and it may not be all that bad.

IIRC there is a oil galley that should have a plug in it that I would say was not put back in after the cleaning.
For the life of me I cant remember were this plug is?
Maybe under the intake manifold or behind the timing cover, just cant remember now as it was like 40 years ago.
Had the same thing happen on a hot little 302 with 351 heads I built for one of our off road 4x4 race trucks.

Maybe ask the machine shop if they would know?
Dave ----

Inside the bellhousing, at the back of the cam?
At least that's one that gets forgotten on 385's

ArdWrknTrk wrote

Inside the bellhousing, at the back of the cam?
At least that's one that gets forgotten on 385's

From what I remember it is internal and why he does not have a oil slick under the truck.
I think on the 385's you get oil coming out the bell housing and most likely all over the new clutch disc if a stick.
Wish I could remember where it was on the motor I built
Dave ----

Ok. I removed valve covers and run oil pump again with drill. With cold oil it barely got to 20lbs pressure and I didn’t see any oil coming from the top of the pushrods. There is some oil in the rockers and the valleys on the heads so I know it was getting a little up there when I ran it.
So then I pulled water pump, timing cover with chain and cam thrust plate. All of the oil galley plugs are in. I run the drill at about half speed for a few seconds and it pumps oil over the top of front crankshaft bearing and through the small hole above the crankshaft. Only half speed cause it will push oil over front crank bearing so hard it will miss the front of the pan..... I am at a loss of what to do next. I don’t want to put it back together because I haven’t found or changed anything.  Thoughts?.?     Thanks

What did the shop say?

Also....maybe test the oil pump. It could be defective? If the block and main bearing clearances are all correct...its got to the the oil pump right?

It seems as if that oil is intended for the crank sprocket and cam chain.

You realize the cam turns at 1/2 crank speed and the ratio of distributor to cam teeth determine the pump rpm.

Whether it's sloppy bearing clearance or some galley plug missing, there's a reason why you don't have any oil pressure.

Can you tell us more about this hole above the crank? How big is it? Can you post a picture of it? Is it supposed to have a plug in it?

All the shop said was check the iol gallery plugs.  Here is a photo of the hole i mentioned. The second and third pictures are of the oil running over the first crank bearing. Hard to see i know. Thanksthe white arrow is pointing at hole.

2 things come to mind.
What does the cam plate look like, dose it have a "wing" that covers that hole?
Are you sure that port is not threaded for a plug?

I know on the 302 I did it was something so simple to over look like that hole needing a plug.
Dave ----

I'm guessing that hole is supposed to have a plug in it, but you'll have to check with your engine builder.

Found out the hole just below the cam is a Oiler that the cam thrust plate covers. That plate has a groove in it to move oil to the end of the shaft and cam gear.

Time to pull engine, and plasti-guage the main bearings to check for proper clearance???

If all oil galley plugs are in place, and you know for sure the oil pump isnt defective....what else can it be other than bearing clearances being too big?

Have you double checked your oil pressure guage to make sure it is ready properly? Maybe you mentioned that in a previous post. Forgive me if you had. I dont have time to read everything.