RamjetVette

The problem: We just had my daughter's 87 (bone stock L98) rebuilt and when we cranked it up, we were getting no oil out the pushrods--either side. We do have good oil pressure at the gauge.

We had pulled the block and had a machine shop rod the block and hone the cylinders and put in the cam bearings. Can anyone explain to me how the oiling system works? I understand there is a rifle bore hole for oil the length of the block above the cam. I suspect the oil is pumped into this and oils the cam thru holes in the bearings (which have to be aligned with the oil holes in the block.) But how do the lifters get oil? There is a hole in the side of the lifter and a hole in the side of the lifter opening in the block. Is there where oil is pumped from that main oil channel? Any ideas why we might not be getting oil to the top end? This is both sides of the engine, all pushrods. Did we leave a plug in that we should have pulled out on assembly?

Thanks guys!

FoolCrzy

did youprime the system before start-up? There as a priming tool made. Basically you pull the distributor, insert the priming tool (which you attach to an electric drill), and spin the oil pump shaft until you see oil...

ANTI VENOM

If you are priming and are using a "screwdriver" and not a shaft from a distributor, that will happen. The oil flows around the distributor to get to the lifters. Other than that, I can't think of why you wouldn't have pressure.

RamjetVette

We didn't prime the system but wouldn't it fill after the engine was running a bit?

CFI-EFI

FoolCrzy, ANTI VENOM,
Priming, properly or improperly, or not, would not prevent the system from eventually pressurizing once it was fired. With the gauge showing pressure, the lack of oil to, and through, the push rods, indicates a blockage, of some sort, somewhere.

I can't explain EXACTLY how the oil is routed, but I would bet on a mis-installed rear cam bearing.

RACE ON!!!

Bowtie8

Are the rocker too tight and bottoming out the lifter?

FoolCrzy

I agree! I just didn't know if he had only run the engine for a few seconds and shut it down since there was no oil.

c4cruiser

If there is no oil going up the pushrods, doesn't that also mean that the lifters are not getting any oil? I would think that if the engine runs for any length of time, the oil that may have been in the lifters would be forced out as the valvetrain operates.

The lifters do get their oil from that hole in the lifter boss. It could be that the oil passages to the lifter gallery were not cleaned out or some piece of debris from somewhere in an oil gallery has clogged the opening to the lifter passage.

The oil gallery for the cam is directly above the camshaft and the lifter galleries are on either side and just below the camshaft oil gallery.

John A. Marker

Since you "rebuilt" the engine, did you replace the lifters, push rods and rocker arms? If you used the old parts then you need to at least replace the rod and rocker arm. I had this happen on a 74 350 and it drove me nuts. I ended up replacing the rods and lifters...that was all it took.

Caboboy

Sorry to hear this Roger......I wouldn't run it until you get this ironed out. I'd definately prime the pump shaft with a drill to see if that works.

As I recall, SBCs don't have priority oiling, so that means oil is pumped to the different galleries off the main feed via the cam and lifter galleries, then down from there. I used to have something on this.... a diagram I think. I'll look for it if you'd like. Meanwhile, check my photos... there's a pretty good shot of the gallery plugs on the back of the new motor. Look at the shot called "cam boss"........that'll show you the physical location of those oil lines

GKK

I'd check the oil pick up tube to make sure it hasn't fallen out of the oil pump and also check to see if the pick up tube is at the correct depth in the oil pan.

Morley

There is a plug in the lower oil galley that MUST be installed or your engine won't get any oil pumped through it.

rodj

"There is a plug in the lower oil galley that MUST be installed or your engine won't get any oil pumped through it"
"I'd check the oil pick up tube to make sure it hasn't fallen out of the oil pump and also check to see if the pick up tube is at the correct depth in the oil pan."

He has oil pressure.
It is just not going to the top end!

JTHVETTE

I just lately had an engine "cleaned" and bored at a local machine shop.
I decided to check behind the "cleaning" job before I washed the engine my self. I first found the rear main oil port from the pump to still have sludge in it and then removed the oil gallery plugs and seals for the cam and valve train and found the same situation there also. So don't assume that it was clean to start with.
BEFORE I did anything else, I would try to prime the oiling system with
a drill. Put a pressure guage in the oil port just above the oil filter and the oil port near the back of the intake manifold to see if there is pressure at both points. If you don't have pressure at either point ,you've got a blockage of some form. Let me know what you find out,then We'll go deeper into the problem.

JTHVETTE

fnseeker

Did you or the shop install the oil pump? A lot of guys will prime the pump with break in grease to help create a stronger pull if you will upon start up. The problem with this is the grease has to get warm to travel up and out of the rockers. I have seen this on some crate or shop rebuilds. I would contact who ever put in the pump and ask. It might all be ok.

JTHVETTE

I like to open up the oil pump and pack it with petroleum jelly prior to installation. I also check the clearance between the pump and oil pan.
once the clearance is set to specs.,I then weld the pickup tube to the pump so there is "NO" chance of it moving.

89C4

When cleaning out the top oil gallery, did you remember to replace the 3 oil plugs in the front of the block? They're 1/4-inch, either freeze type plugs or screw-in's.
Had the same symptoms with my brother-in-law's 350, but then, it was not a L98. Don't know if they differ.

scorp508

With the priming tool I don't believe you'll get oil to the lifters/pushrods. If I remember right (easily could be wrong here) the distrubutor shaft itself creates a seal somewhere in the block that allows the oil to move to those areas. With just the skinny priming tool you'll get oil up to the gauge, but not the lifters/pushrods. For that reason some people modify an old distributor shaft into a priming tool.

RamjetVette

Thanks guys for all the tips. Just some more background: we had probably run the engine for maybe 15 min after the rebuild. The valves were adjusted before starting. We let it run a bit then pulled the covers and noticed no oil out the pushrods. No, we did not replace the lifters, pushrods or rockers as part of the rebuild. The machine shop did the cleaning, honed the cylinders, put new cam bearings in and did a valve job on the heads.

I think based on all the comments above, my next steps are to get the priming tool and give that a go. I have pulled 6 of the lifters, rockers, pushrods and I'll take them down to the machine shop that did the rebuild and see if they have any ideas. I'll bet dollars to doughnuts I'll have to pull the engine and take it back to the shop and have them fix it.

90Indy

I bought a priming tool from Summitt Racing for around $20.00. You can make one but I didn't want to go that route. With the tool and a drill, you will get oil to the pushrods and rocker arms.

I think your idea of trying to prime and see the results is the most logical way to approach the problem. Be patient with the priming tool. It will take a minute or two for the oil to make its way to the rocker arms.

Good luck.

90Indy