There seems to be some
confusion about the true purpose of the lubrication
system in a racing engine. The primary purpose of the
oiling system is to lubricate the engine - period. It is
emphatically *not* the place to look for horsepower in a
bracket racing motor with a wet-sump oil pan. Think of a
sportsman drag racing engine as an endurance motor. It
may only run at maximum power for a few seconds at a
time, but those runs add up over a long season of
racing. If you are a serious sportsman racer, you need
an engine that can make 300 to 400 passes without
looking at the bottom end. From my perspective, that's
the equivalent of running a 500-mile Winston Cup event
or a 24-hour endurance race.
If you want maximum power, the best oil pan is no pan at
all. A total-loss oil system is the ultimate solution
for minimum windage. Many years ago we actually ran such
a system on our dyno. We submerged the oil pump in a
bucket of oil and fired up the engine without a pan. As
you would expect, the dyno cell was a mess afterward -
but we were able to see exactly how the rotating
assembly threw off the oil.
I cite this experiment only as an extreme example of
what it takes to make power with a wet-sump system.
Obviously a total-loss oiling system is impractical on
the race track; the traction and track clean-up problems
would be insurmountable. The simple fact is that more
power requires more pan volume - and the more room you
have to spread out the oil in a wet-sump pan, the less
likely you will be able to keep the oil pump pickup
covered. |
Unfortunately, reliability
usually doesn't sell in drag racing. That's why some oil
pan manufacturers tout the horsepower gains that are
available with trick wet-sump systems. In my opinion,
the places to look for power in a bracket racing engine
are the cylinder heads, the camshaft and the induction
system. It may sound dull, but you should look for
rock-solid reliability and utter dependability in a
wet-sump lubrication system - unless you are willing to
inspect the bearings as frequently as the class racers
who are restricted by the rulebook to wet-sump systems.
Big pans may make more power on the dyno, but the dyno
doesn't duplicate real-world operating conditions. If
you think that baffles and trap doors will keep the
pickup covered, I suggest that you try a simple
experiment. Fill your pan with a few quarts of liquid
that has roughly the same viscosity as hot oil. Tilt the
pan backward at a 45-degree angle - that's the
equivalent of a 1 g launch - and watch what happens. Two
g's is about 60 degrees, and 3 g's (a rate of
acceleration that is achievable by a fast car) is around
72 degrees. You'll see that most of the oil is standing
up against the back wall of the pan instead of
surrounding the oil pump pickup.
Now tilt the pan forward at the same angle to simulate
what happens when the car decelerates. In fact, most
cars are capable of producing more g's on shutdown than
on acceleration. Unless you have a well-defined sump,
the oil pump pickup will almost surely suck air. |
