Chevrolet 70 Series 1970, Service Manual

Page: 412 / 841

53 AND 71 SERIES DIESEL ENGINES 6C-15
flush with the outer face of front cover.
4. Start pulley straight and true on crankshaft.
NOTE: A sp e c ia l in sta lle r tool (J-7773) can
be u sed to in sta ll pulley or an im p rovised tool
co n sistin g of a %"-16 x 4" bolt and a flat p ie c e of
bar stock with a cen ter hole can be used . Bar stock
length should be sligh tly longer than diam eter of
p u lley.
5. A fter p r e ssin g pulley on crankshaft, in­
s t a ll attaching bolt w ith flat w asher to
2 0 0
to
2 2 0
foot-pounds torque.
6
. Install b e lts, radiator and sh eet m etal.
ENGINE LUBRICATION
(6V-53 DIESEL ENGINE)
The engine lubrication sy ste m for the 6V-53N
engine, sch em a tica lly illu stra ted in figu re 19, in­
cludes an o il intake sc r e e n and tube a sse m b ly , an
o il pump, an o il p r e ssu r e regulator valve, a fu ll-
flow o il filte r with a b y -p a ss valve, an o il co o ler,
and an o il co o ler b y -p a ss valve.
The rotor-typ e o il pump is bolted to back of
engine low er front cover and is driven directly by
the crankshaft. Inlet to the o il pump is through a
fix ed -ty p e in let sc r e e n in the o il pan sump.
Lubricating o il from the pump p a s s e s from the
low er front engine cover through short g a llery
p a ssa g e s in the cylinder block. From the block, o il
flow s to the fu ll-flo w filte r , then through the oil
co o le r and back into the front engine cover and
cylin d er block o il g a lle r ie s fo r distribution to
variou s engine b earin gs. The o il drains from the
cylin d er head and other engine p arts back to the
o il pan.
A rep laceab le elem en t-typ e fu ll-flow filte r
in sta lled between the o il pump and o il c o o ler , f il­
te r s the o il p rio r to entering the engine. If filte r
b eco m es r estr ic ted , the o il w ill flow through a by­
p a ss valve, which opens at 18 to
21
p s i, d irectly
to the co o ler.
The o il co o ler b y -p a ss valve is located on the
right sid e of the engine front cover and the o il
p r e s s u r e regulator v a lv e is located on the left sid e
a s view ed from the r ea r of the engine.
If o il co o ler b ecom es restr ic ted , the o il flow
w ill be to a, b y -p a ss valve in low er engine front
co v er, then to the cylinder block o il g a lle r ie s . The
b y -p a ss valve opens at approxim ately 52 p si.
Stabilized lubricating o il p r e ssu r e i s m ain­
tained within the engine at a ll sp eed s by m eans of
a regulator valve located in the low er front engine
co v er. The regulator valve, located in the pump
outlet p a ssa g e , opens at approxim ately 52 p si and
returns e x c e s s o il d irectly to the cran k case.
A ll crankshaft and connecting rod bearings
a r e p r e ssu r e lubricated. O il p a ssa g e s branching off
from the main o il g a llery d irect the oil to cam shaft
end b earin gs, id le r gear and a c c e sso r y d rive gear
b ea rin g s, blow er, and cylinder heads.
O il for lubricating connecting rod b earin gs,
p iston p in s, and for cooling the piston heads is
provided through the d rilled crankshaft from the
adjacent forw ard main b earings. The gear train is
lubricated by the overflow of o il from the cam shaft
pocket through a p a ssa g e into the flyw heel housing.
TORQUE WRENCH SPECIFICATIONS
Torque fig u r es shown are at various points indicated with threads
clean and dry u n le ss o th erw ise indicated.
Item F t.-L b s.
C ylinder Head B olts and Nuts ........................................................ 190-200*
Exhaust Manifold Stud N u t s ................................................................ 30-35
R ocker Arm Shaft B racket B o l t s .................................................... 50-55
P u lley and Damper to Crankshaft B o l t ......................................... 290-310
O il F ilter Center B olt ....................................................................... 40-50 •
O il Pan Drain Plug ............................................................................... 35-40
Rack Control Tube B racket B olts ................................................. 10-12
Front Cover B olts
3 /8 - 2 4 ............................................................................................. 25-30
1 /2 -1 3 ............................................................................................. 80-90
O il Pan B olts ......................................................................................... 10-12
* Bolt and stud threads, nuts, and bolt head contact a reas coated with
International Compound #2 or equivalent. International Compound #2
is available in quart containers - P art Number 5198563.
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCKSHOP MANUAL