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We have had a number of phone calls asking us what
performance increase you get by adding a GX200 Cam, Carb etc
to a standard Honda GX160 engine.
So to be able to answer your questions we decided to find
out by preparing an engine.
We started with a standard GX160K1 engine that had been
used for a few years in MSA racing. It was therefore
completely legal to start off with but had been de-governed,
had GX140 valve springs fitted and a de-baffled exhaust.
Before doing any work we did a few runs on the dyno to
test the HP and Torque. The results can be seen in the
image below with the Red line showing the HP and the Light
Blue line showing Torque before any work was done.
The parts we changed were as follows:-
- The dished piston was changed for a GX160T1 piston
which is a flat top piston. This helps to raise
the compression ratio.
- We also changed the GX160 head gasket for a GX200
head gasket which again raises the compression.
- A GX200 Cam shaft was fitted and two brand new side
case gaskets fitted. This enables some pressure to
be taken off the camshaft enabling some cam float.
- A GX200 Carb replaced the standard GX160 Carb.
- Valves were replaced with standard GX160 valves and
G200 Springs fitted (note not GX200!). The Inlet
and exhaust valve collets were also replaced as a
precautionary measure.
- New Cylinder head bolts were fitted and torqued to
28nm.
- GX160 +0.25 were filed down and fitted to the new
piston enabling a smaller ring gap to increase
compression.
The results of these modifications can be seen in the
image below. The Orange line showing the increased HP
and the Dark Blue line showing the increased torque.
As you can see, its not that there is a dramatic increase in
HP or Torque but the fact that the HP and Torque stay at the
top end for longer. For example the power stays above
5hp until approximately 6400rpm compared to the standard
5700rpm. This enables you to alter your gearing to get
the best performance out of your kart and engines.
There are also other aspects of tuning that we did not
have time to try that would have improved performance
considerably. These include altering the cam shaft and
ignition timing, fitting a new air filter to help the engine
breath better, and porting the heads. However as you
can see by making a few simple mods and swapping a few
standard parts you can get a lot more out of your GX160
engine were rules permit.
Please remember to check your rules if mods are
permitted! |
