Since most of the engine cooling is ac-
2. Apply 40 psi (276 kPa) air pressure to
complished by heat transfer through the
the water jacket and observe the water
cylinder liners to the water jacket, a
in the tank for bubbles which indicate
good liner-to-block contact must exist
the presence of cracks or leaks in the
when the engine is operating. Whenever
block. A cracked cylinder block must be
the cylinder liners are removed from an
replaced by a new block.
engine, t h e b l o c k b o r e s m u s t b e i n -
spected.
3. After the pressure test is completed,
remove the block from the water tank.
NOTE
Then remove the plates and gaskets and
dry the block with compressed air.
Before attempting to
check the
block bore, hone them
throughout
METHOD "B". This method may be used
their entire length until
about 70%
when a large water tank is unavailable,
of the area above the
ports has
or when it is desired to check the block
been "cleaned up".
for cracks without removing the engine
from the equipment which it powers.
However, it is necessary to remove the
1. Hone the block bores as follows:
cylinder head, blower, oil cooler, air box
c o v e r s and oil pan.
1. Attach sealing plates and gaskets as
in Method "A". However, before attach-
ing the last sealing plate, fill the water
jacket with a mixture of water and one
gallon of permanent type antifreeze.
The antifreeze will penetrate small cracks
and its color will aid in detecting their
presence.
Do not use a methoxy propanol
b a s e antifreeze as it is detrimental
to the water seals.
2. Install the remaining sealing plate and
tighten it securely.
3. Apply 40 psi (276 kPa) air pressure to
the water jacket and maintain this pres-
sure for at least two hours to give the
water and antifreeze mixture ample time
to work its way through any cracks
which may exist.
4. At the end of the test period, examine
the
cylinder
bores,
air
box,
oil
passages, c r a n k c a s e a n d e x t e r i o r o f t h e
F i g u r e 11B-10. Honing Bore of
block for presence of the water and anti-
Cylinder block
freeze mixture which will indicate the
presence of cracks. A cracked cylinder
A. Use a hone in which the cutting radi-
block must be replace by a new block.
us of the stones can be set in a fixed
position to remove irregularities in
the bore rather than following the ir-
I n s p e c t Cylinder Block
regularities as with a spring-loaded
hone. Clean the stones frequently
After cleaning and pressure testing, in-
with a wire brush to prevent stone
spect the cylinder block.
loading. Follow the hone manufactur-
er's instructions regarding the use of