ENGINE MECHANICAL -, Description EM-3
The 7M-GE, 7M-GTE engines are an in-line 6-
cylinder engine with the cylinders numbered l-2-
3-4-5-6 from the front. The crankshaft is sup-
ported by 7 bearings specified by the inside of the
crankcase. These bearings are made of kelmet.
.The crankshaft is integrated with 8 weights
which are cast along with it for balancing. Oil holes
‘are built into the crankshaft for supplying oil to the
connecting rods, pistons and other components.
These ignition order is l-5-3-6-2-4 .
The cylinder head is made of aluminum alloy, with
a cross flow type intake and exhaust layout and
with pent roof type combustion chambers. The
spark plugs are located in the center of the com-
bustion chambers.
Exhaust and intake valves are equipped with
irregular pitch springs with symmetrical ends
made of oil tempered silicon chrome steel wire
which are capable of following the valves even at
,high engine speeds.
Both the exhaust side cam shaft and the. intake
side cam shaft are driven by a single timing belt.
The cam journal is supported at 7 places between
the valve lifters of each cylinder and on the
cylinder head of front end. Lubrication of the cam
journal and cam is accomplished by oil being sup-
plied through the oiler port in the center of the
camshaft.
Adjustment of the valve clearance is done by
means of an outer shim type system, in which
valve adjusting shims are located above the valve
lifters. This permits replacement of the shims
without removal of the camshafts.
The resin timing belt cover is made in 2 pieces.
Pistons are made of highly temperature-resis-
tant aluminum alloy, and depressions are built into
the piston head to prevent interference with
valves.
Piston pins are the full-floating type, with the
pins fastened to neither the piston boss nor the
connecting rods. Instead, snap rings are fitted on
both ends of the pins, preventing the pins from
falling out.
The No. 1 compression ring is made of stainless
steel and the No. 2 compression ring is made of
cast iron. The oil ring is made of a combination of
stainless steel. The outer diameter of each piston
ring is slightly larger than the diameter of the
piston
and
the flexibility of the rings allows them
to hug the cylinder walls when they are mounted
on the piston. Compression rings No. 1 and No. 2
work to prevent the leakage of gas from the
cylinder and the oil ring works to scrape oil off the
cylinder walls to prevent it from entering the com-
bustion chamber.
The cylinder block is made of cast iron. It has 6
cylinders which are approximately 1.6 times the
length of the piston stroke. The top of the cylin-
ders is closed off by the cylinder head and the
lower end of the cylinders becomes the crankcase,
in which the crankshaft is installed. In addition,- the
cylinder block contains a water jacket, through
which coolant is pumped to cool the cylinders.
The .oil pan is bolted onto the botiom of the
cylinder block. The oil pan is an oil reservoir made .
of pressed steel sheet. A dividing included
-inside the oil pan to keep sufficient oil in the bot-
tom of the pan even when the vehicle is tilted. This
dividing plate also prevent5 the oil from making
waves when the vehicle is stopped suddenly and
thus shifting the oil away from the oil pump suc-
tion pipe.