Ford 1956 Truck User Manual

Section a-Cylinder Block, Pistons, Piston Rings, and Connecting Rods and Bearings
29
F;g. 44-No rmal Wear Pattern
WEAR AREAS
6609
a bent connecting rod. The normal wear pattern of a
piston is shown in fig. 44.
In spect the piston pins for signs of fracture or etch-
ing. Ch ec k the p in f or proper fit in th e piston and rod
bushing. Ch ec k for wear in the pin retainer grooves.
(2) REPAIRS. Replace pistons showing signs of ex-
cessi
ve s kirt cl earance, or ring side clearance, wavy ring
land s, fr ac tur es or dam age fr om detonation or pre-
ignition.
R ep l ace piston pins sh owing signs of fracture or etch-
ing. Piston pins that show wear or fit l oosely in the
piston or rod bushing should be replaced. R eplace all
pist on pin retainers.
(3) FITTI NG PISTONS. Pistons of 0.020, 0.030,
0.040,
0.060 inch oversize are avai l able for most engines .
Check the parts cata l ogue for sizes available.
To fit a piston in a cylinder bore, calculate the size
piston des ir ed by taking a bore check (fig. 40) and sel ect
the proper size pis ton to provide the desired clearance.
Ch eck the pi sto n being fitted by a tt ac hing a tens i on
scale to th e e nd of a feeler gauge ribbon (1/2 inch wide)
of the proper thickness. Position the feeler on the side of
the piston 90 ° from the piston pin hol e. Invert the piston,
then pu sh the piston a nd f ee l er into the bore parallel to
the cranks h aft axis. H old the piston and pull out the
feel er ribbon, noting the readin g on the pull scale
(fig. 45).
If the sca le reading is greater than the maximum
allowable pull, rech eck calc ul at i ons to be s ur e the proper
si ze pi ston h as been se l ected, check for a damaged piston,
try a new pi sto n, or hone the cy lin der to obtain the
proper fit.
If the sca le re adi ng is less than the mmimum allow-
ab le pu ll , r ec he ck calculations before trying another
Fig 45-Fitting Piston-Typical
piston. If none can be fitted, bore the cy linder to the next
size piston. When a piston has been fitted, mark it for
assembly in the cylinder to which it was fitted .
NOTE: A.ll pistons are tile sOine weight, both standard
and oversize; there/ore, pistons oj va rious sizes can
be i1ltermixed without upsetting engine balance. Re-
bore only the cylinder or cylinder' which requir e it.
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•
..
•
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6485
Fig. 46-Measurin9 Piston Ring Gap-Typical

Ford 1956 Truck Specifications

General

Brand	Ford
Model	1956 Truck
Category	Automobile
Language	English