Proper Assembly Lubrication Part II

It has been brought to my attention that the use of grease (white lithium
or moly) as an assembly lube can cause sudden, energetic disassembly of an
engine whilst running.

The reason is quite simple, really. Think of grease as SAE 10,000 oil. It
is sort of like STP, only thicker yet. If you would fill your crankcase
with STP and attempt to start an engine, the oil pump would break.
Likewise, if you coat every part with grease, there is a chance you will
clog oil galleries and discharge ports with SAE 10,000. Hence, oil
starvation. After a few minutes running, plain bearings will melt and
after a few hours, valves will stick in their guide bushings. Lets not
forget that a prime function of oil is to cool engine parts and it cannot
cool if it does not circulate. Grease can cut friction, but not cool
because it does not circulate, so that is why oil and not grease is used in
high speed combustion engines. Grease is perfect for wheel bearings
because there is no combustion and heat is low. It makes perfect sense
once you begin to think about the problem.

It seems some older motorcycle engines do not provide sufficient pressure
to push out the grease clogs and the engine runs dry and soon you have a
bucket of bolts. Just because your "motor" has an oil pump does not mean
some parts are not gravity fed! And gravity cannot circulate SAE 10,000
oil.

Instead of grease, I now recommend SAE 30 non-detergent. Squirt this on
every part as you assemble your bike engine. You can't go wrong with this
advice.

 

Nomen Nescio wrote:

Or a person could just follow the recommmendations in their factory
service manual.

 

Which generally calls for engine assembly lube (a special grease
designed to disolve harmlessly into oil, widely available at auto parts
stores).

Methinks the Anonymous One is still stuck in the 1950's, prior to such
innovations.

- Elron

 

I think there is some truth to your assesment. Next thing you know he
will be talking about the time he drove a Terraplane off the dealers
showroom floor.

pierce

 

Don't...bogart...that...joint...my friend!
Pass it over...to me!

 

Gee! Thats why all my rebuilt engines explode.....NOT.
The tiny amount of grease used as assembly lube could
not possibly have any measurable effect on the viscosity
of 2 or 3 Quarts of crankcase oil you nit.
MadDog

 

wrote in @z14g2000cwz.googlegroups.com:

I have never seen an engine that had exploded. Not one. I have heard many a
story or three but not once did I ever see one.

I have seen holes in the side of blocks, holes in oil pans, sieves engines,
overheated engines that warped all the valves and ever warped the head. I
even saw a head launch off a block, but never an exploded engine. I saw a
tank blow up in a video once but that was because of a particularly strong
explosion that was induced by someone who wanted to blow up the tank. Pretty
amazing stuff those munitions are.

pierce