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

BEARING-CLEARANCE CHECKING
ROTATING METHOD Connecting-Rod Bearings-Connecting- to coincide with the bearing width
The simplest way to confirm you've rod bearings can be checked with the you're checking. The bearing and jourinstalled
the correct size bearings for a crankshaft out of the block. This is nal must be free from oil because
given size bearing journal is, first ro- because the pistons cannot be installed Plastigage is oil-soluble, and any oil
tate the journal in the bearing, orvice in their bores for the check. For will cause a false reading, When
versa in the case of connecting rods, to checking a rod bearing, install the rod checking the crankshaft, all the other
check for insufficient clearance. If the On its bearing journal after you've caps and bearings must be in place and
rotation is free it's OK. TO check for oiled the journal or bearing. Torque tightened first, Lay the Piastigage on
excessive clearance, try to rotate it 90' the rod-bolt nuts to specification, then the top of the bearing journal or
to the normal direction of rotation. If rotate the rod around on its journal. If centered in the bearing, and caresome
play, or movement is felt, the it's free to rotate there is enough clear- fully install the cap with the crankclearance
is too much. Let's look at ance. Now, try wiggling the rod side- shaft laying in the block on its new
how this applies to crank and rod ways. If there's no movement the clear- bearings, but without its rear-main oil
bearings. ance is not excessive and the bearings seal. Or, the piston and rod assembly
Crankshaft Bearings-Install the crank- are OK. must be positioned against its bearing
shaft using the methods outlined in
journal. Torque the bolts or nuts to
this chapter. If you are using a rope- PLASTIGAGE METHOD specification. Be careful not to rotate
type oil seal, don't install it until after Plastigage is a strip of wax which, the bearing and journal relative to each
you've checked the bearings. With the when installed between a bearing and other, otherwise the Plastigage will
crankshaft in place, the bearing caps its journal, flattens or squeezes out to smear and you'll have to start over
installed and their bolts torqued to a width inversely proportional to the again. After you've finished torquing
specification, rotate the crankshaft by clearance between the journal and the the cap, remove it and measure the
hand. If it rotates freely, the bearing bearing. Plastigage comes in a Paper bearing clearance by comparing the
clearances are enough. To check for sleeve with a printed scale for measur- squeezed wax width with the printed
excessive bearing clearance, lift the ing the flattened Plastigage. It reads scale on the Plastigage sleeve.
crankshaft by its nose. Try to wiggle out directly in thousandths of an inch It's not necessary to check all the
it up and down. If you don't feel any bearing-to-journal clearance. You bearings unless you want to be particumovement,
or play, clearance is not bought green Plastigage to measure larly careful. One thing for sure, you
excessive and you can proceed with 0.001-0.003-inch clearance range. can't be faulted for checking to be
your engine assembly. To use Plastigage, cut a length of it certain.
Line up staggered holes of the cam thrust
plate, then install the two 1/4-inch bolts.
Torque them 9-1 2 ft.lbs.
solvent such as lacquer thinner-both
front and back. The same thing goes for
the inserts too. The actual bearing surface
will be coated with a white residue
as it comes from the box. It's OK, just
wipe the bearing enough so you're certain
the working surface is clean.
429/460 crankshaft and related components. Note load-spreader ring just back of
automatic-transmission flex plate. Some engines use it and some don't. If yours does, use
it. Photo courtesy Ford.
ENGINE ASSEMBLY 97