|Watts Shop Performance
| Titanium rods offer the highest strenght-to-mass ratio of all the
rods. A well designed Titanium rod is about 20 percent lighter than
a comparable steel rod. Titanium is the most abundant element in
the earth's crust, but it must be alloyed with other metals before it
has the properties needed for the manufacture of connecting rods.
The most common alloy is called "Titanium 6-4" because it has 6
percent aluminum and 4 percent vanadium to improve
Like steel and aluminum rods, titanium rods can be forged or
cut from billet. Given a choice, titanium rods are most durable when
manufactured by the forging process. This is because the grain size
of even the best aerospace grade titanium is less than steel. In a
Richter-esque grain-sizing scale where a 6 rating is twice as tight as
a 5 rating, titanium rates between 5 and 6 while high carbon steel is
far more cohesive, rating as a high as a 9. To offset the possible
negative impact on strength, a fully machined forged titanium rod is
the best type thanks the improved grain structure around the big
end versus a cut out true billet titanium rod.
Though raw titanium cost five times as much as raw carbon
steel, the average retail cost of a set of titanium rod is only about
twice that of steel. The increased consumer cost reflects the fact
that titanium becomes "gummy" when machined and requires
specialized tooling and slower feed rates. Titanium expands at
about the same rate as steel and is resistant to work hardening, so
you could run then in your street car. So where do titanium rods
really shine? In any all out racing effort where an approximate 15
percent reduction in ultimate tensile strength is an acceptable trade
off for an approximate 20 percent reduction in connecting rod
weight. As for ultimate power capacity, know that they're used in
everything from 9,000 rpm NASCAR motors to a handful of 6,000
horsepower Top Fuel motors (though most teams use aluminum).
With the right communication between you and the manufacturer,
they'll handle anything you can throw at them. Just be sure not to
scratch them!!! Titanium is very "notch sensitive". Small surface
imperfections caused by rough handling must be polished
immediately or they can grow quickly.
Contrary to popular myth, titanium rods will not evaporate if
they come into contact with aerosol carburetor cleaner. What is true
is that prolonged exposure to the stuff will cause oxidation that can
cause surface inclusions and eventual fatigue points. To be safe,
clean titanium rods with mineral spirits or water based cleaners.