Harmonic waves can travel thru the drive
train and thru the crank. If there is nothing at the end
of the crank to absorb the wave, it will travel back in
the opposite direction to meet the next wave. This causes
the unfavorable harmonic vibration. The first thing to take
the abuse is the oil pump gear and you know what happens
when that breaks. ALSO, pulling weight off of the crank
that close to the center line will add ZERO horsepower or
rpm capability. Don't fool yourself on this. Think of how
big and thick the counter weights are on a crankshaft. The
harmonic balancer is just another externally added counterweight
that happens to absorb negative wave energy. Honda engineers
were not stupid or naive. Don't try to out think them in
this case, use a harmonic balancer.
abuse the drive train launching at 8000 rpm and shifting
over 10,000 rpm. The aluminum under the flywheel bolts started
to eat away and the flywheel started to vibrate back and
forth. When it came completely loose it sent a shock thru
the crank so strong that it snapped the key holding the
harmonic balancer in place. The balancer spun on the crank,
put the crank fired ignition out of time and shut the motor
off. When pulling everything apart, we found that the shock
wave had actually also bent the crank to the point where
it was unusable again. This proved to me the useful purpose
of a harmonic balancer. We run steel flywheels now, BTW.
Since writing this, we have started selling the ATI line
of dampers for the following reasons..
1)The ATI damper continues to dampen vibrations
to unlimited rpms whereas the fluid unit loses its effectiveness
at about 7000 rpm. Check the graph below.
ATI is 1.25 pounds lighter than the fluid unit.
3)The ATI is rebuildable.
4)Viscous fluid dampers are sealed. The
inertia weight can become locked by bearing failure or,
more commonly, from the silicone turning to a solid mass.
Your first warning of damper failure will probably be a
broken crankshaft resulting in the replacement of your damper
and the engine.
5)ATI units are used on all NASCAR engines
as they were designed specifically for high performance
engines. Their design is fail safe, efficient and available
for any engine application. They are SFI certified.
6)Bolt on crank trigger wheels available
with the ATI.
7)ATI was able to build a custom damper
for our race car. It is for a S2000 engine with a Chevy
bolt pattern to help us connect our dry sump pump to our
8)Much more detailed information here.