Pro Series Wave Loc Bolts
For the most severe applications, in conjunction with aftermarket
I-beam rods, ARP has developed the "Pro" Series Wave-Loc
bolts. These ultra heavy-duty rod bolts are made from a special
material designated ARP2000. It has approximately 200% the fatigue
life of 8740 chrome moly steel and has a tensile strength of
about 220,000 psi, and is capable of more than 12,000 lbs. clamping
surface contacts the rod and cap for optimum alignment and
reduction of fluctuating stress - which strengthens the
snug fit for all OEM connecting rods (interference range
of .001" to .005"), despite wide range of factory
rod bolt hole tolerances.
material grain flow because of patented Wave-Loc surface
design as compared to knurled bolts that have sharp edges
and "built-in" stress risers.
and scoring of the rod is virtually eliminated because there
is only smooth contact and absolutely no "digging."
NOTE: ROD BOLTS
Unquestionably the most important fasteners in any engine are
the connecting rod bolts, as they hold the key to the entire
rotating assembly. A broken bolt will lead to a catastrophic
engine failure. As you can imagine, the most critical joint
is where the connecting rod halves mate. The rod bolts must
support the primary tension loads caused by each rotation (or
cycle) of the crankshaft. When the crank rotates, the big end
of the connecting rod essentially becomes oval-shaped and the
rod bolts bend. As the crankshaft continues to rotate, the rod
becomes round again. With alternating tension loads and cyclic
bending of the bolts, it is very important to install fasteners
that are able to exert a clamping force greater than the load
imposed upon the join (tension).
In addition to utilizing a rod bolt with sufficient strength
to withstand the tremendous cyclical strains placed upon it,
it is absolutely imperative that the bolts be properly tightened.
The preferred method of monitoring the correct amount of tension
is through use of a stretch gauge. This is far more accurate
than using a torque wrench. Moreover, through subsequently checking
the rod bolts length at teardowns, it is possible to determine
if it has been stressed beyond safe limits and must be replaced.