UHitAXV if. OF 1- VOSAKA-CnASOPMOH 
944 
FOREST AND STREAM. 
[Dec. ii, 1909- 
The Proper Installation of a Marine Motor 
The success with which a motor boat may 
be operated and the degree of satisfaction it 
gives its owner depends so much upon the 
proper installation ot the motor that this phase 
of the motor boat subject should receive the 
most careful attention that the builder is able 
to give. We will take it lor granted that the 
reader has purchased a motor boat with engine 
and complete equipment and is in doubt as to 
just the method ot procedure with respect to 
the installation of his power plant. 
There are so many types 01 installations, de- 
oending upon the type of motor and boat, that 
space will not permit of a lengthy discussion 
here but the writer will select as his theme 
the installation of one type as being typical ot 
the operations necessary to correctly placing 
a marine motor. The general method of pro 
cedure for all installations is the same, varying 
only in point of detail. . , 
We will assume that the shaft log is bored 
and ready to receive the propeller shaft, ihe 
next step is to design the engine foundation. 
In selecting wood for the foundation, some care 
must be exercised. Procure some good pieces 
of oak, if possible, and as free from flaws and 
knots as you can find. If oak is not readily ob¬ 
tainable, use any close-grained hardwood that 
might be easily found in your vicinity, lor 
engines up to 15-horsepower, use 2-inch stock 
and for engines above that rating, 3-mch lum¬ 
ber is better. Place your boat upon suitable 
supports and level it both lengthwise and side¬ 
ways. In leveling lengthwise, place a straight 
edge along the keel, inside the boat, and then 
place a spirit level on the straight edge. In 
leveling sideways, place straight edge across the 
coaming. 
Having leveled the boat and blocked it, so 
that it will maintain this position, stretch a 
strong string or a piece of small wire through 
the center of the shaft log hole and extend it into 
the boat some distance beyond the proposed en¬ 
gine foundation. Be sure that the sti etched 
wire passes exactly through the center ol the 
hole in the shaft log and not to one side or the 
other. Say the shaft log hole is 1 H inches in 
diameter, then with a rule, measure the dis¬ 
tance from the sides of the hole to the string 
and adjust the string unil the distance from any 
point on the circumference is exactly n-xo ol 
an inch. Secure the string in this position. 
This string represents the center line of the 
engine and propeller shafts when in position. 
Now decide how much space you will need 
between the inner face of the stuffing box and 
the rear end of the motor bed, for the reverse 
gear. In the smaller size of boats, only 
one stuffing box is used for the propeller shaft, 
and this is usually placed on the outer face 
of the shaft log. This space is determined by 
measuring the gear bed, or if your gear is not 
handy at the time of making the foundation it 
is safe to allow as a minimum at least 36 inches 
for this dimension for motors up to and includ¬ 
ing 30-horsepower. The reverse gear and en¬ 
gine bed should both rest on the foundation 
timbers. The distance between the inner faces 
of the bed may be found by measuring the 
width of the flange on the motor, allowing that 
the bolt holes in the flange should be bored at 
least one inch from either face of the bed 
timbers. 
Having determined on these proportions, 
cut out two or three cross pieces to conformto 
the shape of the boat and upon which the bed 
timbers are to rest and to which they are secured 
by means of lag screws. The side timbers are 
the next pieces to shape and may be done in 
the following manner. 
' Measure the distance on the motor from the 
center line of the crank shaft to the lower face 
of the crank case flange. This dimension will 
be the distance from the string to the lop face 
of the bed timbers at all points. Shape the side 
timbers and cross pieces and bolt the whole 
frame together by means of lag screws before 
placing in the boat to receive the engine. Ihe 
cross member may be bolted directly to the 
keel by means of bolts put through from the 
K. 
Fig. 1.—Engine Bed. 
underside of the boat. In putting these bolts 
in place, put a washer under the head and coat 
it with thick lead paint before drawing up tight 
on it, thus preventing leakage at this point. 
After the foundation is in place, measure the 
distance from the string to the top face of the 
bed timbers again in order to be sure that the 
face of the timber is parallel with the string. 
Secure the bed to the keel by drawing down 
on the bolts after you have measured to find 
whether or not the center line of engine bed is 
directly over the center of the keel. Remove 
Fig, 2.—Engine with Reverse Gear on Engine Bed. 
the string through the propeller shaft hole aim 
place the engine and reverse gear on the beu 
timbers. Insert the propeller shaft and secure 
the outer stuffing box temporarily in place with 
small screws. Suspend a plumb bob from one 
head in line with the keel center and arrange 
to adjust this line, so that it can be brought to 
within an eighth of an inch from the end ot the 
propeller shaft. Chalk the end of the propeller 
shatt and find the center with a pair of dividers 
and place a prick punch mark at this point. 
Now bring the plumb bob line close to the end 
of the shaft and adjust the stuffing boxes until 
the plumb line falls directly over the prick 
punch mark. Block up the shaft in this 
position, remove the temporary screws and in¬ 
sert the regular lag screw, binding the flanges 
of the stuffing boxes down against the face of 
the shaft log, which has been previously coated 
with thick lead paint. Now we are ready for 
the engine. 
Place the engine and reverse gear on the 
timbers and line the three pieces up temporarily 
by bringing the faces of the couplings together 
and with the aid of the plumb bob, see that the 
center of the engine and reverse gear shafts are 
directly over the center of the boat. Now mark 
on the timbers the position of the bolt holes in 
the flanges of the motor and gear beds, then re¬ 
move both gear and the motor from the founda¬ 
tion and bore the holes in the bed timbers to 
receive the holding down bolts. Replace the 
foundation; line it up again with the keel and 
with the spirit level placed across the top, then 
secure permanently to the keel. Put engine and 
reverse gear on the bed, place flange and 
coupling bolts in place loosely and then wait tor 
the final lining up until the boat is in the water. 
The fuel tank is usually placed in the bow 01 
the boat and the fuel led to the motor through 
copper or block tin pipe. Copper tanks are best 
for holding gasoline, but rather expensive. A 
good, heavy coated galvanized iron tank, riveted 
and well soldered, gives very satisfactory re¬ 
sults under all ordinary conditions. . In big. 3 
a well made tank is shown and will perhaps 
serve to give the reader an idea as to the style 
and make up of a fuel tank of approved design 
In making gasolene connections, all points 
should be smeared with ordinary brown kitchei 
soap, as this is more effective than white leac 
for this purpose. Two stop-cocks should be 
placed in the fuel supply pipe, one at the tan! 
and one near the carbureter, to prevent loss o 
fuel in case there should be a leak somewhere 
in the pipe line between the tank and the car 
bureter^ater intake p j pe should lead from tin 
pump to a point in the boat far below the water 
line, close to the bottom, and there should 
a stop-cock placed thereon to shut off the 
water supply when the engine is at rest for an. 
length ot time, to prevent the water from escap 
ing into the boat should there be any leaks 11 
the connections or around the pump plungei 
It is well to make the connection between th 
pump and the intake with a wire-bound rubbe 
hose, as this eliminates the possibility -of th 1 
vibration being transmitted to the intake con 
nection, which would tend to work it loose a 
the planking. This same principle applies t 
the water outlet which should be piped to 
point above the waterline. In making wate 
connections, be sure and smear the joints wit 
a thick lead paint, preferably white lead, an 
then screw the pieces together very tight wit 
the regular pipe wrench. 
There are virtually two kinds of exhaust n 
stallations; namely, the atmospheric and tl 
under water exhaust. In the atmospheric ei 
haust system, the pipe is led from the engn 
directly to a point above the waterline, boirn 
times it is advisable to use a muffler with th 
type of installation, owing to the disagreeab 
noise. In Figures 4 and 5 > we see the atmo 
pheric exhaust system shown very clearly. 
In the case of the under water exhaust sy : 
tern, as shown in Fig. 6, no muffler is require 
as the water itself performs this functio, 
There is, however, one danger attendant upc 
the installation of the under water exhaust, at 
that is this. Be sure and arrange to preve 
the water front backing up in the pipe when tl 
boat is reversing. There should be a reli 
cock placed in the exhaust pipe near the engir, 
and when starting, this valve should be open; 
in order not to draw any water through t 
pipe and into the motor. The pipe should ha 
a decided slant from the motor to the outh 
as shown in Fig. 6. When the pipe leaves t, 
boat at right angles to the surface of the wat 
at that point, the water will not back up in 
the pipe any more on the reverse • than on t 
go ahead, but, on the other hand, you will n 
