| Chapter
4, Mile Post #5:“Installing the engine structure
to the Chassis”
(Click here to read Chapter 3.)
Start Date 10-15-08
The
next big challenge was to install the Harley 80 cid.
Engine and establish a strong and easy to service engine
mounting system. The base weight of the 80 cid. Engine
is about 120 pounds without the carburetor, air cleaner
and other miscellaneous Harley supplied brackets. With
this low weight it was decided to use Harley designed
rubber engine mounts (isolators). A part number was
selected that would give good movement while controlling
the “Harley Shake” and allow items like
the exhaust and other attachments to move freely when
mounted on simple rubber Lord mounts. |
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| A
strong connection was made between the engine mount and
rubber isolator while still allowing good access to mounting
bolts. The
main difference between a four / aft mounting Engine
mounting as used in a motorcycle and the side-to-side
mounting in our car was the different locations of the
engine mounts on the crankcase of the engine. Sturdy
steel adapters were made to allow the engine rubber
isolation mounts to be placed at the 3 and 10 o-clock
positions in relation to the crankshaft center. This
would allow for “even” movement from side
to side and still control the overall movement and keep
it to a minimum. |
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The
adapter which connects the crankcase mounting to
the rubber isolator can be seen below the rubber
isolator.
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Once
these were in position we fabricated strong 1”
dia. support arms which connected the Firewall
and Chassis side rails to the isolators. These
support arms were welded in a “V”
pattern which spread the load and still allowed
for easy access to the mounting hardware.
Under
the engine we installed a 1-1/4” dia. tube
which connected the two side rails and acted as
a locator for the “Panhard” tube and
“Shock Absorber” anchors. This “Cradle”
mounting system gives strength and simplicity
to the whole installation. At this time it is
not certain if we will weld in place this support
tube or make it removable so that it can be chromed
and or modified for different types of engines.
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This is an early photo showing the location
of the support tube and the method of selecting
location.
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Once the engine was in its “Cradle Mounting”
we installed a Firewall blank. This simple flat panel
was done four different times to get the shape and size
right and it is still under review. This Firewall must
perform a number of different tasks. The Firewall must
mount the engine ignition coil; provide access to the
control cables, be a part of the body mounting system
and looking good all at the same time. The Firewall
is intended to be made from 3/16” thick aluminum
plate. This type of construction will allow for buffing
to give a chrome appearance, anodizing for special colors,
painting to match body design and graphics scheme and
still be light weight. The last challenge was to keep
it simple and “inexpensive”.
As can
be seen in this photo a number of Chassis tubes are
connected to the backside surface of the Firewall.
More will be discussed about these tubes and their
function in later chapters. It is enough to say that
the “Firewall” is a very important part
of the construction, safety of the passengers and
equipment.
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The
TigerCat has tubes, tubes and more tubes. To make the
complete Chassis stronger “Triangulation”
of the Chassis tubes and side rails are required. The
space behind the Firewall is also the fuel tank area.
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We
will talk more next time on adding parts and systems to
the Chassis. Brakes and controls, oh what fun!! - Carl
Myers
Click here to read Chapter 5. |
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