Military-Vehicles: RE: [MV] M38A1 - Fuel Pump Question...(dry starts)

RE: [MV] M38A1 - Fuel Pump Question...(dry starts)

Alan Bowes (alan_bowes@phast.com)
Wed, 13 Aug 1997 10:59:46 -0600

Hi,

Dry starts, even after just a few hours of sitting, are hard on engines. =
Estimates vary considerably on the amount of engine wear attributed to =
the first few seconds after startup (until oil pressure comes up), but =
it is a very significant factor. After sitting for months or years, the =
surfaces in the engine will not only be extremely dry, but there will =
probably be small pockets of corrosion that can cause further damage =
when you turn it over.

Here's a simple set of steps you can take to minimize the chance of =
damage to the engine after it has been sitting for a long time:

1) Buy a few gallons of cheap oil and FILL the engine to a level just =
below where it would overflow the top of the block and begin seeping =
into the intake or exhaust manifolds.

2) Let it soak for a few hours so that the oil can seep into all of the =
interstices (crank and cam bearings, piston pins, rings, valve =
stems/guides, oil pump, etc.).

3) Remove the spark plugs. This will allow the engine to be hand cranked =
more easily and without exerting extra pressure on the bearing surfaces.

4) Crank the engine (gently) two or three revolutions BY HAND to make =
sure that the piston rings aren't rusted to the cylinder walls. If =
they're rusted to the walls, it can break a ring, bend or break a land =
on the piston, or score the cylinder wall. (A little oil might get =
pumped out of one or two of the spark plug holes, so keep a rag handy.)

5) If it turns over OK by hand, drain the oil back down to its normal =
level. Otherwise let it soak longer.

6) Wait about half an hour to make sure that any oil that may have been =
filling up a cylinder or two has drained back down into the crankcase.

7) Leave the spark plugs out and crank the engine with the starter motor =
until the oil pressure comes up.

8) Replace the spark plugs and start the engine normally.

If you've got a good engine that you don't want to rebuild for a while, =
my oiling method is well worth the small amount of effort.

Some people may think that this is overkill, but it's NOT. It's easy, it =
will only cost a few coppers for the cheap oil, and it is the ONLY way =
that I know of to get oil EVERYWHERE inside the engine before starting =
it.

A pre-oiler is good for bearings, but it won't pre-lubricate your rings, =
piston pins, or valve guides, except for a few isolated spots where a =
little oil might squirt out of con-rod piston lube holes. Likewise, =
cranking the oil pump with a drill motor has the same limitations, and =
it's a lot more work than my recommended method.

Once the engine is up and running, I'd personally recommend using 100% =
synthetic oil. I've been running it for years in different =
vehicles...even my lawn mower...and I'm completely sold. It maintains a =
good protective film that reduces dry start wear, doesn't coke on hot =
engine parts, flows more easily when it's cold, and has better =
high-temperature shear characteristics. Costs more, but I think the =
reduced wear and tear is well worth it. It also has some SLIGHT benefits =
in terms of power, fuel economy, and reduced engine heat. It will also =
maintain higher hot-idle oil pressure. Note that in all cases, I =
switched to synthetic from non-synthetic and had NO problems whatsoever.

Regards,

Alan Bowes
(Salt Lake City, Utah)

-----Original Message-----
From: Scott Strance [SMTP:Strance@msn.com]
Sent: Tuesday, August 12, 1997 8:41 PM
To: mil-veh@skylee.com
Subject: [MV] M38A1 - Fuel Pump Question...

I'm getting ready to start my M38A1 after it has sat for several years. =
I=20
will be changing all fluids prior to starting it.

I noticed that the oil filter tank had a strong smell of fuel and the =
oil=20
appeared to be very thin. I believe that the only way this could have =
occured=20
was either the fuel pump was leaking or the oil had thinned over time.

Any ideas?...

Also, does anyone have any recommendations on a procedure to follow for=20
starting it after such a long time? I was going to pull the plugs and=20
ignition, squirt some WD40 in the spark plug holes and turn it over a =
few=20
times to check compression. Is that safe with these engines?

Also, would you rebuild the carb prior to this? I fear the gaskets are =
very=20
dry and will leak like a sieve.

Thx in advance!
Scott
53 M38A1=20

=3D=3D=3D
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