How To Rebuild Your Ford V-8 351C-351M-400-429-460.pdf - Index of

Checking deck-surface flatness with ground-steel bar and feeler gages. I prefer limiting
surface irregularities to 0.004 inch, however 0.007 inch is allowed over the full length of
the block.
Regardless of the boring bar used, mainbearing
caps should be torqued in place.
Use boring bar to remove only enough
material to clean up bore to accept next
largest oversize piston. 0.002-0.003-inch
honing stock is left.
Treat "decking"
- .
your block in the
same manner as you would milling cylinder
heads. If more than 0.020 inch is
removed from the block, you'll also have
to surface your intake manifold due to a
mismatch being created between the
heads and the manifold. You may also
run into pushrod-length problems if your
engine is equipped with non-adjustable
rocker arms. Refer to pages 77-78 and
117-118 for more on this.
Because a block is cast-iron, a special
welding process is required to repair it.
The block must be preheated prior to
welding, and a nickle-alloy rod used to do
the welding. After the notch is welded,
the raw weld must be machined flat, or
made flush with the block's deck surface.
Although it's not your problem, this is
not as easy as it sounds because a nicklealloy
weld is very hard and nearly impossible
to machine, consequently it must be
ground. Not all automotive machine shops
have block-grinding equipment. Your
problem is the cost of having it done.
Compare this cost to that of a replacement
block.
For less-severe surface irregularities,
check your block, particularly if there
are signs of gasket leakage. You'll need
an accurate straight edge at least 6-inches
long and some feeler gages. Use your
gages to check for any gaps between the
block deck surface and the straight edge.
If your straight edge extends the full
length of the block, the maximum allowable
gap is 0.007 inch. However, if your
straight-edge is 6-inches long, the maximum
is 0.003 inch. These two figures
equate to basically the same amount of
warpage. If you find block warpage,
check back a couple paragraphs for how
much can be taken off your block's deck
surfaces.
A final thought about surfacing your
cylinder block. If one deck surface requires
surfacing, the other one must be
done whether it needs it or not. This
maintains equivalent deck heights from
side-to-side and ensures that the intake
manifold will seal.
Other Checks-Other than checking your
block for cracks, bore taper and deck
flatness, there's not much more to look
for. In the normal course of things,
nothing can go wrong with a block. For
example, the valve-lifter and distributor
bores are lightly loaded and so drenched
in oil that they just don't wear. The only
problem would occur if they were damaged
by a broken connecting rod which
somehow got into the cam and lifters.
This would require junking the block.
To be sure the lifter bores are OK,
check them with a new lifter. Do this
without oiling the lifter or the bores.
Insert the lifter in each bore and trv
wiggling it-if there is noticeable movement,
the bore is worn and the only way
of correcting it is to replace the block.
Sleeving a lifter bore is possible, but
difficult to have done.
If you're building a racing engine,
another check you'll need to make is for
crankshaft bearing-bore trueness-making
sure each bore is on the same centerline.
The easiest way of doing this is to spin
your crank after installing it on its bearings
in the block-the crank should be
checked for runout first. If the crankshaft
turns freely, your block is OK as is the
crankshaft.
A final check for cracks and your
block can be considered sound. Be particularly
attentive if you have a 351M/
400 cast prior to March 1, 1977 at the
Michigan Casting Plant. The water jackets
were prone to cracking immediately
above the lifter bores. Refer back to pages
27 and 28 for a more detailed description
of this problem.
CYLINDER-BORE FINISHING
Plain Cast-Iron, Chrome or Moly Rings-
When you drop your block off to have it
bored or honed, you should know the
type of piston rings you intend to use so
you can tell the machinist. Your engine's
final bore finish should be different for
plain, chrome or moly rings. So, what
type of rings should you use
Chrome rings are especially suited for
engines that will inhale a lot of dust and
dirt such as a truck used in a rock quarry.