when the rpms come up and the manifold pressure comes up your
brains go out the exhaust' (Quote from well-known race pilot.)
Thank goodness we did not have a repeat of last
year when the Reno air races were shut down due to the despicable
acts of the terrorists. This report will focus on the Unlimited
Class aimed at the techies and gear heads. Its spotlight will
be the 'behind-the-scenes' goings-on that keep these remarkable
racers in top form. The format of this report will be a day-to-day
description of the scuttlebutt and overview of mechanical
issues and tweaks made to the racers. Up until the final Sunday,
weather conditions were simply perfect; dry, no wind although
quite hot, average temperatures were in the low 90s each day.
By Saturday afternoon, winds had started to pick up. Sunday
morning dawned with the wind still blowing and by Sunday afternoon
wind gusts were in the 40 mph range. Not only did this make
the already difficult job of flying these ultimate racers
even more difficult, the sand storm kicked up by the winds
made visibility a serious issue. And goodness knows how much
damage was inflicted upon the airframes and engines after
being sand blasted at speeds of over 500mph.
Although taken for granted in the auto racing
world, wireless telemetry is now taking hold. This over due
innovation now allows the pilots perform their primary job
� that of flying the airplane without worrying about temperatures
and pressures etc. Instead, the ground crew can now monitor
all the instruments in the cockpit. In this way, if anything
should start to go away, the pit crew can alert the pilot.
It also keeps the pilot 'honest' by not over boosting or over
revving the engine. Top teams typically have a plan as to
how much power is required to win a race. The pilot dials
in this power and hopefully does not have to exceed it.
Sunday September 8:
The great thing about arriving several days before the 'official'
event starts is the fact you can drive your car right into
the pit area. After Monday, the line of demarcation kept getting
pushed back until by Wednesday, September 11, I had to park
in the 'official' spectator's parking lot which meant a long
walk. Ah well, I could use the exercise any way.
One of my first stopping-off places was the
Dago Red pit. Prior to being shut down on 9/11, 2001 Dago
Red suffered a cracked cylinder head during a practice run
which necessitated the replacement of the 'B' bank and head
assembly. In the off season, the original bank was mated to
the replacement head and at the same time six new pistons
Upon arrival at the Dago Red pit, it was apparent
that this highly modified P-51D was in serious trouble. The
day before disaster struck when it fell off a jack (don't
ask..!!). Considerable airframe damage was wreaked upon the
rear fuselage, coolant exit door and perhaps most significantly,
the elevator. Dago Red's team jumped into high gear. First
order of business was to put in an urgent call to Dago Red's
brilliant and charismatic crew chief; Bill Kerchenfaut. Bill
has been in the racing game seemingly forever and commands
the respect of every team. If anyone could pull off a miracle,
Bill would be the guy. After driving all night, he set to
and started hammering away on the airplane � literally and
figuratively. When I arrived at the pit Bill was under the
dog house pounding away at the coolant door with a ball peen
hammer. Work continued at a furious pace throughout Sunday.
progresses at a furious pace on Dago Red. In this
shot the left elevator is seen removed.
masters at work. David Fagoaga on the left and Bill
Kerchenfaut on the right repairing Dago Red's elevator.
The devices sticking up through the skin are called
Clecos and are used as a temporary expedient to
hold the skins together until permanent rivets can
Voodoo is another highly modified P-51D. Sporting what is
arguably the most attractive paint scheme it was nice to see
this formidable aircraft in the pits. Last year Jack Hovey
had built up a race engine for it. Unfortunately, during a
test run at a relatively modest 90 in.Hg. manifold pressure,
two connecting rods let go. Cause of the failure was a back
fire in the induction system. At the time no one could figure
out the cause of the back fire. In the ensuing year, it is
thought that stale fuel may have been the culprit. Jack rebuilt
the blown-up engine � but not to full race standards. However
at 90 in.Hg. and 3200 rpm Voodoo was no slouch either. A P-63
propeller hub assembly drove T-28 blades and an AD Skyraider
regulator accounted for some of Voodoo's impressive performance.
behind Voodoo is Jack Hovey, one of the most experienced
Merlin re-builders in the business. Jack has built
the winning engine for a number of unlimited Gold
Racers. For this year, Voodoo's engine was mildly
modified running 80 in.Hg. and 3200rpm. Low induction
temperatures and high oil temperatures were just
two of the challenges for this team.
Miss America went through an engine change to
replace the stock ferry Merlin with a full blown Rick Shanholtzer
race engine. This race engine featured the usual go-fast modifications
including G6 Allison connecting rods and a Pete Law ADI system
modified from a Pratt Whitney R-2800 CA3 unit. The question
is often asked; why use the ADI regulator from an R-2800 when
an ADI regulator was developed in the 1940s for the Merlin
by Bendix. The simple answer is; no parts. However, parts,
i.e., diaphragms for R-2800 CA3 ADI regulators are plentiful.
A badly cracked propeller extension shaft didn't help the
engine change go smoothly. But, another one was soon scrounged
up to replace the cracked one.
of the two styles of blade & fork connecting
rods used by Allison with the V-1710 (top) and Rolls-Royce
with the Merlin (bottom). The more complex 'marine
block' style Rolls-Royce rods are replaced by the
stouter Allison rods in some race prepared Merlins.
(Allison drawing courtesy of Dan Whitney).
undergoing an engine change to replace the ferry
engine with a Rick Shanholter race engine, Miss
America's crew found this distressing sight � a
badly cracked propeller extension shaft.
Another Allison rodded engine for this year's
races was the ultimate sheep in wolf's clothing. Stu Eberhard's
P-51D is deceptively stock looking and yet lurking under that
innocuous looking cowl is a race Merlin with Allison rods.
Bill Rheinschild's P-51D was another wolf in sheep's clothing.
He too had a race Merlin that ran 105 in.Hg and 3500 rpm.
These two aircraft were well matched having relatively few
airframe modifications and yet sporting race Merlins.
One of the big surprises this year was #232, Michael Brown's
constantly improving Sea Fury 'September Fury' powered by
a Wright R-3350 PRT (sans PRTs) engine with direct fuel injection.
He did a 462mph lap � on 17 cylinders..!!! The dropped cylinder
was caused by a failed ignition coil. Remember this engine,
like all the other R-3350 powered racers, uses low tension
ignition. That means each cylinder has its own ignition coil
so if this coil fails then the cylinder goes dead. Clearly,
this was one airplane to keep an eye on. A major contributor
to September Fury's dramatically improved performance was
a revised ram air induction system. Stock Sea Fury's powered
by the original Bristol Centaurus featured a pair of induction
scoops in the wing leading edge at the wing root. Each ram
air scoop fed induction air to the twin entry, two speed supercharger.
Each entry was on the side of the blower housing so locating
the ram air scoops in the wing leading edge made perfect sense.
Not so with the R-3350 with its down draft Bendix PR-58 carburetor.
Getting ram air to the carburetor involves some complex ducting
with multiple 90 degree bends when taking induction air from
the leading edge. All these bends and manipulations of the
air are not good for pressure recovery. Last year September
Fury showed up with a short ram scoop located on top of the
cowling. For this year, the ram scoop extended to the leading
edge of the nose bowl. The scuttlebutt in the pits claimed
an additional 10 in.Hg. was available at speed with the newly
configured ram scoop. Optimized for high speed, the scoop
probably did not supply full pressure recovery at low air
speeds. But this aircraft still had more than enough power
for take-off chores.
ram air induction scoop installed on 911 September
Fury. Reportedly good for 10in.Hg., it had a remarkable
effect on the performance of this aircraft.
Check Mate, the Yak powered by the R-2800 'bitsa'
engine, was another aircraft that underwent considerable tweaking
and improvement during the off season. Its R-2800 is made
up from a CA3 power section and CB17 supercharger � among
other things. Another significant improvement was the installation
of an R-2800-44 nose case. Dash 44s had the lowest reduction
ratio of any R-2800; .350:1. This nose case is extremely rare
as its only application was the North American AJ Savage and
relatively few of these aircraft were built. With its cut-down
Douglas AD Skyraider prop, the R-2800 could now turn it at
a more efficient speed due in no small part to the 350 nose.
Stability about the longitudinal axis was always of concern.
A larger vertical stabilizer fixed that issue.
Pratt & Whitney R-2800 CA3 powered Yak � Check
Mate. Most noticeable change for this year was the
new vertical stabilizer of larger area.
Law, on the left, and the owner of Check Mate, John
Moore on the right, discuss a carburetion issue.
The perennial Grumman F8F Bearcat, Rare Bear,
has fallen on hard times. A no show last year, this year it
was hoped it would return to its former glory as the fastest
unlimited racer. Alas, that was not to be. A newly rebuilt
R-3350 had been installed shortly before Reno but persistent
problems plagued this aircraft and its team. Initial attempts
at running resulted in no oil pressure and no scavenging.
Before the oil problems were figured out, over 20 gallons
of oil were pumped into the engine. The primary culprit for
low oil pressure was the installation of an incorrect oil
ferule that acts as an oil transfer tube between the power
section and the blower section. Once this gremlin was figured
out, attempts at starting resulted in sever back-firing. Normally
one would not be over concerned with engine back firing. But
not with engines fitted with Bendix injection carburetors.
This remarkable fuel metering device measures mass air flow
and based on this meters the appropriate amount of fuel into
the engine. The mass air flow measuring and fuel metering
is accomplished via sensitive rubber diagrams. Bendix carburetors
depend on a carefully calibrated fuel pressure; too much and
the fuel diaphragm will be damaged, too little and the engine
will run lean � if at all. It turned out that the fuel pressure
had been cranked up to the point where the fuel diaphragm
had indeed been damaged. The resulting overly rich mixture
caused the back fires, further damaging the diaphragms. A
recently flow checked spare carburetor was installed. Now
the engine responded far more favorably to the extent high
power runs were made on the ramp. But the Bear was not out
of the woods. A lengthy squawk list needed to be attended
Devil is in the details. An incorrect oil ferrule,
on the right, was installed on Rare Bear's R-3350.
When the correct one was fitted, shown on the left,
oil pressure came up and the engine scavenged as
Critical Mass is another 'top-of-the-heap' 3350
powered racers. It has all the right modifications; PRT engine
and the hard to find EA2 nose case with .355:1 reduction gearing.
With a potential 4,000 hp Critical Mass was a racer to be
reckoned with. That is until disaster struck. After a good
practice run, Critical Mass was taxiing to the pits when the
gear folded up on pilot Tom Dwelle. Serious airframe and engine
damage was inflicted on this superb racer.
Sunday morning Critical Mass sits proudly in the
pits. Just few hours later, this magnificent airplane
was seriously damaged.
Mass prior to the gear collapse calamity.
sight of a mega-buck Aeroproducts Skyraider prop
sight of Critical Mass after the gear fold incident.
Serious damage was also inflicted upon the outer