Mike,
As Fred pointed out, time to replace those jackshaft bearings.
A MAJOR CONCERN: The orientation of the jackshaft bearings
will let three little oil holes all line up correctly. The
oil feed comes in from the main gallery. One hole feeds the
rear main bearing, the other hole supplies oil to the camshaft.
If the rear jackshaft bearing is installed in correctly:
YOU WILL HAVE NO OIL TO THE CAMSHAFT. 1600 camshaft bearings
are different, as it does NOT have the hole to the camshaft.
I keep a little 1/16" rod and "poke down those holes" to make
sure the jackshaft bearing is lined up correctly. Most machinist
will line up the BOTTOM hole correctly, and may overlook the
other holes. Yikes!
I what until the black comes back from the machine shop. Usually
they will hot tank it first, then do the honing, etc. I have a
nice "ball hone" that I use when installing new rings during
a "minor engine fresh up" (block in the car, I'll replace rings
and rod bearings, minor valve job, new chains -- all this around
60K to freshen up a motor). When I pull the block I'll go the
full nine yards.
Once the block comes back from the machine shop:
I put it on my engine stand. Get a bucket of hot sudsy water
with good ol nasty TSP detergent (used to be common, cuts
crease nicely), a hose, and a big squirt bottle of WD-40
(cheaper by the gallon!).
I'll hose down the block, and scrub like crazy. WD-40 the
bores to prevent rust, and air dry the hole thing. Makes a
big ol' mess, and confirms to the neighbors you are just
plain crazy.
With my safety face shield on, I then use the air compressor
to air dry the block.
For the SAE THREADED HOLES (this is both on SAE and METRIC BLOCKS)
I'll take an old 7/16-14tpi threaded head bolt, cut a couple of
grooves down through the threads with a triangle file held inline
with the bolt. That old bolt is now a "tread chaser". run it in
and out of the hole several times. Nice and clean bolt holes, little
dental pick, and a shop vac, help clean out all the crud in the
bottom the the bolt holes. Once all the bolt holes are "prepped"
I'll still go back and use a 60 degree counter sink to remove
the top thread of the hole. Prevents thread pulling, and cross
threading later on. Little time consuming details.
Lots of time with thread chasers, and cleaning everything up
nicely. Once that block is spotlessly clean, and scrubed. Good
time to paint it. tape off the top & bores, cardboard on the
bottom to keep pain out of the bores. Nice even coats of
paint (I use GM Corporate Blue -- pretty close to the OEM
Nissan Blue.) One pattern laid on horizontally, next pattern
vertically. One stroke with a "up spray" one with a "down spray"
so you cover both sides of the ribs, etc.
Let the block bake out in the sun for a good afternoon. Ideally
wait a few days before starting the rebuild.
OTHER TIPS:
Oil galley. Just knock out those plugs. I drill a hole in the
front galley, and use a 18" long 1/8" strong rod... knock out
the back plug. Flip the rod around, and knock out the front
plug.
A set of "engine brushes" are used to scrub the main galley
out. Ditto all passages to main bearings, etc.
Hand held grinder: remove any "flashing" in the casting. Also
I pay attention to that oil drain hole in the back of the block.
Don't remove metal, only the little flashing that could break
off later.
If you are really into it, paint the bottom of the block with
GLYPTAL. Nasty smelling stuff, but will stay on forever and
coat the bottom casting with a nice smooth surface. Out doors,
on a day with a light breeze is best. Still I'll skip this for
all but race engines, as I hate the smell.
After all this rinsing, scrubbing, rinsing, etc. Everything should
be nice and clean, and there should not be any junk in the
radiator after a rebuild!
Cheers,
Tom "little fanatical than most" Walter
Austin, TX
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