I understand that an engine should be pre lubed before the first start after a rebuild but if the mechanic that rebuilt the engine used whatever they use, some kind of grease on all the parts, wouldn't that be good enough? A friend of mine said that he has rebuilt a number of engines with the grease stuff and started them as is and never had an issue. It seems like a pain to do the pre lube if it's still greased up. But I don't want to waste 5k on a rebuild. Would pouring oil over the rockers and letting it drain down help some?

Brad
Sierra Vista Arizona
1954 Lincoln Capri

There are multiple reasons to prelube.  One is to ensure that the oil pump works and that the system can achieve adequate pressure.  Another is to ensure that the filter and passages are full of oil so there is minimal delay in the supply of oil through the system.  Yet another is to ensure that oil makes it all the way through the system, which is a reassurance that it is assembled correctly.



Lawrenceville, GA

The length of time that an engine sits after being rebuilt before being started for the first time is also a player.  Time is your enemy on a freshly built engine and any initial lube applied to the bearings and engine components can slowly disappear.  As Charlie brings up, prelubing restores the initial lube as well as putting lube in places it was not originally applied.

While engine oil or a very viscous lube is recommended for engine assembly purposes, the use of ‘white’ or lithium grease is typically considered detrimental for engine assembly purposes.  Some reasons for not using ‘grease’ for the engine assembly components includes potential hydro locking or deformation of the bearings when they are torqued down, the inability of oil to flow past that grease during the initial startup, cold grease stopping up the oil filter until the engine warms up, and the grease actually drying out and getting crusty if it sits for too long before the engine is cranked up.

Here are some pictures of commercially available engine bearing assembly lubes.  Keep in mind that the lube used for flat tappet camshafts differs significantly from the lube used on engine bearings.
    

    

   

Lorena, Texas (South of Waco)

Is like to hook up an oil pressure gauge while I'm spinning the oil pump to ensure I'm getting proper pressure. Where do I attach the gauge? The engine is out of the car.

Brad
Sierra Vista Arizona
1954 Lincoln Capri

Any of the plugs that are on the side oil line.  You don't have to spin the whole engine over.  Spinning the oil pump by the pump drive located in the hole for the distributor will do very nicely..  I even do it by hand but this won't give you an indication of pressure, just that you are getting oil all the way up.  Use a drill to rotate the drive for that.  Make sure you spin counter-clock wise





54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I'm not sure if understand . The side oil line. Plugs? Do you mean spark plugs? I tried to spin the oil pump shaft from under the dizzy but wasn't sure i was engaging the shaft with the socket on the extension. I spun it ccw with a drill for a couple of minutes but didn't see any oil coming up to the heads. I used a cheap cordless drill, maybe it didn't have enough power to spin fast enough.

Brad
Sierra Vista Arizona
1954 Lincoln Capri

Any of the ¼” NPT oil galley plugs on the filter side of the engine will work for an oil pressure gauge hookup.  There is a ¼” NPT hole on each side of the block for a coolant drain but it will be in a different ‘line’ than the oil galley plugs.

I prelube the engines using a speed handle and starting with an empty filter it takes ~20 seconds to get pressure at the oil galleys.  It then takes roughly another 20-30 seconds to get a flow up to both rocker arm assemblies.  This is with a speed handle which is lucky if I’m getting 300 rpm at the pump.  If the oil pump was not prelubed during the engine assembly, then the oil pump may have a hard time getting the oil flow started.  A leaking rubber seal at the oil pump inlet can also prevent a speedy pickup of the oil.

Lorena, Texas (South of Waco)

I see that the oil pump shaft is not centered in the hole in the block. That's why I'm not sure the socket is turning the shaft, it might be spinning on top of the shaft. Is there a trick to keep the shaft centered while putting the socket in the hole? Plus it'll help putting the dizzy back in.

Brad
Sierra Vista Arizona
1954 Lincoln Capri

Ted wrote - 

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I use a 1/4 drive deep socket on an extension with  speed wrench (3/8  with an 1/4-3/8  drive adapter) to make sure the socket connects with the oil pump shaft/drive.  An ordinary length socket may not reach the oil pump drive..  Usually, the socket will just go over the drive - never had a problem with centering (except when putting in the distributor).






54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ