Oil Filter By Pass Vaive; Piston Selection - Chevrolet CAMARO 1979 Service Manual

In Line 6 6A1-25
5. Measure the cylinder wâlls for taper, oulof-round
or excessive ridge at top ofring trâvel. This should be done
witha dial indicator. Setth€ gage so rhar rh€ rhrust pin musr
be forced in abour l/4" ro enrer gage in cytindif bore.
Center gage in cylinder and tuin diâlto "0". Carefully work
gage up and down cylinder to determin€ râper and turn it
to different points aroùnd cylinder wall to determine the
oùt-of-iound condition. If cylinde.s were found to exceed
specifications, honing or boring will be necessary.
Condilioning
The performance of the following operation is
conlingenr upon engine condir'on âr lime of repaif.
If the cylinder block inspection indicated that the block
was suitable for continued us€ except for out-of-round or
tapered cylinders, they can be conditioned by honing or
oonn8.
Ifthecyiinders were found to have less than.005" taper
or wear they can be condition€d with a hone and fitted with
the high limit standard size piston. A cylinder bore ol less
thân .005" wear or taper may not entirely clean up when
fitt€d to a high limit piston. Ifit is desired to entirely cleân
up the bore in these câses, it will be necessâry to rebore for
an oversize piston. If more than .005" taper or weâr, they
should be bored ând hon€d to the small€st oversize that will
permit complete r€surfacing of all cylinders.
When pistons are being fitted and honing is not
necessary, cylindû bores may be cleâned with a hot water
and detergent wâsh. After cleâning, the cylinder bores
should be swabbed several times with light engine oil ând
a cleân cloth and then wiped with â clean dry cloth-
Eoring
L Before using âny type boring bar, the top of the
cylinder block should be filed off to remove any dirt or
burrs. This is veryimportant. Otherwise, theboringbârmây
be tilted which would result ir the rebored cylindel wâll not
being at right ângles to the crânkshaft.
2. The piston to be fitted should be meâsured with a
micrometer, measuring at the center ofthe piston skirt and
ât ght angles to the piston pin. The cylindei should be
bored to the same diameter as the piston and honed to give
the specified clearance,
NOTICE: Hone cylinde$ as outlined ùûder "Cylinder
Honing and Piston Fitting'.
3. The instructions furnished by the manùfacturer of
the equipment being used should be cârefully followed.
Honing
l. when cylinders are to be honed, folloiv the hone
manufacturer's recommendations for the use of the hone
and cleâning ând lubicâtion dùring honing.
2. Occasionâlly duing the honing operation, the
cylinder bore should be thoroughly cleaned and the piston
selected for the individual cylinder checked for corrcct fit.
3. When finished honing a cylind€r bore to fit a piston,
the hone should be moved up and down ât a sufficient speed
to obtain very fine unifoam surface finish marks in a crcss-
hatch patt€m of approximately 45 to 65 degrees included
angle. The finish marks should be clean but not sharp, free
from imbedded pa icles and tom or folded metâ1.
4. Permanently mark the piston for the cylinder tc
v hich it has been fitted and proceed 1o hone cylinders and
fit the remaining pistons.
CAUTION: Handl€ the pistons with care
and do not attempt to forca thom through
the cylind€r until the cylinder has beon
honêd to correct size as this type piston
can bo distorlêd through
car€l€as
handling.
5. Thoroughly clean the bores with hot waler ând
detergeni. ScIÙb well with â stiff bdstle brush and rinse
thoroùghly wiih hot water. It is extremely essential that â
good cleâning operation be perfomed. Ifany of the abrasive
mâterial is allowed to remain in the cylinder bores, it will
râpidly wear the new rings and cylinder bores in addition
to the bearings lubricated by the contaiminated oil. The
bores should be swabbed several dmes rvith light engine oil
ând â clean cioth and then wiped with a clean dry cloth.
Cylinder should not be cleaned with kerosene or gasoline.
Cleân the remâind€r of the cylinder block to remove the
excess material spread during the honing operation.
OIL FILTER BYPASS VALVE
Insp€ction ând R€plac€m€nl
With the oil filter removed, check the sping ând fibre
valve for op€râtion. Inspect for a cracked or broken valve.
If replacement is necessary, remove valve by prying it out
with a screw driver. Install and seat â new valve by tâpping
it in place, using a 9/16 thin-wall deep socket.
DISTRIBUTOR LOWER BEARING
Replacament
The distributor lower bearing is a bronze bushing
pr€ssed into th€ lower side of the engine block. Its upper
inside diameter pilots the distributor shaft ând the outside
diameter extending below the block pilots the oil pump.
The lower bushing will ordinârily require only a
cl€ârânce or wear check during engine overhaul. When
distributor shâft-to-bùshing cleâmnce exceeds .0035" the
bushing should be replaced âs follows:
L With oil pump and distributor rcmoved, install Tool
J-9534 into bushing and using â slide hâmmet remove the
bùshing.
2. Cleân bushing bore in block and check for burrs ol
damage.
3. Using Tool J-9534 with driver-bolt in driver hândle
install driver into new bùshing froft large inside diameter.
4. Position bushing ând driver to block ând drive th€
bùshing in position, which is determined by tool bottoming
âgainsr the block.
5. Remole tool from bushing. It is possible thât the
bushing with minimurn LD. will collaps€ enough during
instâllation to slightly seize the installer arbor. If this
happens, remove installer tool using slide hammer in driver
bolt hole or driver hândle.
NOTICE: This will not damage the bushing and tool
is designed for this purpose, should it occur.
PISTON SELECTION
L Check USED pistor to cylinder bore clearance as
lollows:
a. Measure the "Cylinder Bore Diameter' with a
telescope gage 12-1/2' (64mm) from top of cyliûder borcl.