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I believe that an
informed customer is a better customer. Whether I'm
buying a laptop for my daughter to take to college or a
new CNC machining center for our shop, I like to know as
much as possible about the product before I sign on the
dotted line. So in this spirit of full disclosure, I'm
going to tell you something you need to know about
racing engines: The more powerful the engine, the more
maintenance it requires.
That statement may seem
self-evident, but some racers simply don't make the
connection between horsepower and upkeep. As interest in
Top Sportsman, Top Dragster and other fast sportsman
eliminators skyrockets, more racers are opting for
big-inch, high-horsepower engines. Unfortunately, they
don't always ratchet up their maintenance schedules at
the same time.
When Buddy Morrison and I
started building big-block Chevrolet V8s 20 years ago
for bracket racing and heads-up sportsman eliminators, a
468-cubic-inch Rat that made 675 horsepower was a
"killer" engine. Now our shop can scarcely
keep up with the demand for 622ci big-blocks that
produce nearly 1,300 horsepower. Think about it: We've
increased displacement by 30 percent while nearly
doubling the output. A top-of-the-line 622 sportsman
big-block now produces more power than a
state-of-the-art 500ci Pro Stock engine. Add a dose of
nitrous oxide to one of these big-inch sportsman
powerplants and you've got a serious contender for any
all-out doorslammer or dragster category.
While power levels have
escalated dramatically, the basic package hasn't changed
since the '60s. We are still using the same bearing
sizes, the same crankshaft design, and the same lifter
bores that debuted on the original big-block Chevy in
1965. What has changed, however, is the stress that we
inflict on these components.
Everything I've learned
about engines can be summarized in one sentence: You
increase an engine's power by increasing its cylinder
pressure. Period. You can raise cylinder pressure by
adding cubic inches, improving airflow, injecting
nitrous oxide, or pressurizing the induction system.
Regardless of the method, the inevitable result of
higher cylinder pressure is more stress on internal
components.
When cylinder pressure and
rpm climb, you have to beef up a wide range of parts to
withstand the higher loads. The thickness of the wrist
pin walls has to be increased and the head gaskets have
to be supplemented with wire O-rings. As camshaft
profiles become more aggressive to fill bigger cylinders
in less time, the lifters, rocker arms, and valve
springs must be upgraded. And it's not just the engine
that feels the effects of more power. The stress on
transmissions, torque converters, rearends and axles
also multiplies.
A few years ago, our 509ci
Super Series big-block was considered a big engine, and
we still build a fair number of them. Assembled with
aftermarket steel cranks and connecting rods, these
engines have exceptional life expectancy. Some of my
customers have raced for six or seven seasons on the
original block, crank, and rod assembly. We've
periodically replaced pistons, lifters, rockers, and
valve springs, but the basic package is nearly
bulletproof. At the other end of the scale, a 622ci
big-block with aluminum rods, a lightweight
reciprocating assembly, and a camshaft with .900-inch
lift requires much more frequent maintenance - I'd say
it's due for an inspection after 100 runs.
If a racer who is accustomed
to making 400 runs between rebuilds decides to step up
to a much more powerful combination, then he or she also
needs to adopt a much more intensive maintenance
schedule. Similarly, people who are new to our sport
must recognize that racing engines are not street
engines. They require frequent care and feeding to
remain healthy.
Owning a fast race car is
similar to owning a private airplane, and I've had
experience with both kinds of machinery. Several years
ago we got a great deal on a twin-engine plane - but
while we paid far below its market value, it still cost
a bundle of money to maintain. That's because there are
no shortcuts on aircraft maintenance. Our plane's paint
was a little faded and its interior wasn't pristine, but
the parts that mattered to me - the engines, propellers,
landing gear and air frame - were in first-class
condition. Other pilots have different priorities:
they've got trick paint, the latest gee-whiz avionics,
and lavish cockpits - but their engines are down on
compression, their magnetos need rebuilding, and the
landing gear is in rough shape.
I care more about how
something works than how it looks, so it makes sense to
me to spend money on proper maintenance rather than on
impressing people. I often see parallels at the drag
strip - the racer with polished valve covers and bad
valve springs, or the dragster with chromed parts
everywhere and leaking shock absorbers. I'm not down on
people who want their cars to look good; I just hope
that they pay as much attention to the parts you can't
see. The fact is that no one ever won an award for the
best-appearing bearings or the best-engineered lifters,
but those are just a few of the parts that are
absolutely crucial to engine performance and
reliability.
I don't expect every racer
to spend countless hours working on an engine - after
all, that's what keeps Reher-Morrison and other
professional engine builders in business. People have
busy lives, and many sportsmen competitors have business
and family obligations that compete for time with their
racing. I don't think a serious sportsman racer needs to
pull the valve covers after every run like we do in Pro
Stock - but I think it's only reasonable to check the
valve springs for tension and lash at least once every
race weekend. Take a look at what gets trapped inside
the oil filter and run a compression test regularly. A
little time spent on preventive maintenance can save big
money in the long run. ###
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