No oil pressure, but oil is moving.
 

I have a rebuilt 460 with 5-6k miles on it. It had oil pressure on the factory guage before it was pulled. I took the motor, put in a summit cam/lifter set and a summit timing set(straight up) and all new seals/gaskets. I put it in my truck and when I fired it up I had no oil pressure on the factory guage or the mechanical guage. I shut the motor off and dismantled the truck. I still have the 460 hanging in my garage and am kind of curious what went wrong. I pulled the distributor last night and ran the oil pump with a drill. Oil came squirting out of the port for the mechanical pressure guage. The oil filter is full as well. How is it that oil is getting around but not building pressure?

was the distributer turning the pump?
forget the pump drive or?????

You didn't happen to have that engine up for sale on craigslist did you?

Assuming the bearings etc are new and properly clearanced, I would look for missing oil galley plugs.

Did you replace the cam bearings when you replaced the cam? Maybe you blocked an oil hole?

Is the engine running smoothly otherwise? If a lifter popped out it would dump most of the oil.

Was the oil pressure good before you pulled the engine out of the donor?

Don't know for sure which seals you replaced, but I assume no oil holes were blocked there?

You probably have an internal leak somewhere, but enough pressure to keep oil moving. Usually the leak is bad bearings dumping most of the oil into the pan, but like I said, I assume those were OK prior to the cam change.

Good Luck,

Jim Henderson

Second vote for the gallery plug in the timing case.

Just guessing, but have heard about cam bearings spinning in the 385 series blocks & could be one has spun in the past & now when installing that new cam, it got pushed out of its hole so the oil is just flowing out past that area & not building presure at the sending unit.
Neil

The pump drive is in, and it is hooking to the distributor.


Yes, it has been on CL.


I didn't replace any bearings, I figured they should all still be good with such low mileage on the rebuild. In the donor truck, the oil guage read in the middle at idle and would climb with the rpms. As far as the seal/gaskets, the only ones I didn't change were the head gaskets. I changed the rear main, but I put that bearing back in the way it came out.

If I remove the timing cover I will see this galley plug? I don't remember pulling any plugs, but I may as well check.

I hadn't heard of that, but if thats the case I would probably just keep trying to offload this thing. I am considering putting it in my 86 F-250 if I can get it sorted.

Top end oil goes first to the front side of the passenger lifter gallery.
There is a plug in the end of that drilling.
(not recommending these mods, but here is a good graphic representation of the oil passages) http://www.enemyracing.com/oilsys.html

Missed it in the first post but if it ran 5-6K miles without a problem, and you did nothing to the block but only swapped cams and lifters I would think the issue is there.


Are the lifters loose in their bores?
Perhaps Summit pulled the wrong item or the engine was rebuilt w/ oversize due to scoring.

The lifters I put in fit as snugly as the ones I removed. I guess I will pull the timing cover and check the plug. I'll let you know what I find next week, heading out of town tomorrow so I'll be packing today.