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GREG JONES | EDITOR
In our June issue, we put a spotlight on valvetrain component selection – specifically camshafts, lifters and valve springs. Of course, there’s more
to the valvetrain than just those parts. Enter valves, rocker arms and pushrods! All of these components work in conjunction and the selection
process for the proper parts can sometimes be daunting and complex. But valvetrain selection can also be boiled down to a few simple facets that if
followed, can greatly help your selection process and keep your engine out of failure trouble.Valves e selection of the proper intake
and exhaust valves require taking
into consideration the spring pressure
applied when the valve is on the seat
and in the open position. Numerous
valve materials and coating variations
are available depending on the speci c
requirement for a given engine.
“Titanium valves are good if
the builder is trying to save weight
and isn’t worried about cost,” says
QualCast’s Adrian Long. “Stainless
steel is a more robust material if the
builder is looking for durability,
longevity and cost savings. Sodium-
lled valves are another option and
Inconel is called for if you’re working
with exhaust valves. Stellite, which
is a super durable, premium alloy on
the face of the valve, is necessary for
corrosion and high-heat applications.”
According to Dan Gathman,
vice president of operations at Elgin
Industries, their PRO-STOCK
performance valves are made from
21-4N material, which is best for
heat resistance. ey’re also swirl
polished to aid in air induction into
the cylinder.
“Valve choice for size (length)
will depend on if you are using stocksprings or are adding length for
extra lift (spring installed height),”
Gathman says. “For material selection
you should never substitute a lower
grade then originally speci ed by the
manufacturer, but you can always go
to a higher grade for longer life and
increased heat resistance.”
In addition to the valves
themselves and their composition
and design, you’ll also want to look
at valve seat composition. Are you
going to run a real tight tulip on
the exhaust? Are you going to run a
radius margin or a square margin on
the valve?
“ ere are so many nite details
on what you’re trying to do that it
can literally make or break you on
whether or not the engine makes
horsepower,” Wilson says. “For a
street application where I want to
push a little bit more horsepower, we
will suggest running a bronze guide to
keep things cooler, softer and better
for the valves. If you’re making a lot
of max-e ort power, we like running
a MoldStar 90, which is an alternative
to beryllium. CHG also makes a
fantastic valve seat.
“In terms of the valves themselves,Valves, Rocker Arms and Pushrods
VALVETRAIN
40-43 eb.aug20 Valvetrain.indd 40 8/7/20 8:32 AM
Naresh Jariwala