By November of 1995 the Army Of Darkness had forgotten about the
heartache of one-off motor building and set to planning the 1996
season. Although the logical choice would have been to install
a set of higher lift cams and flat-slide carburetors into our
tried and tested FZR 560 (see RRW Feb, 1996) which would virtually
guarantee racing success in the regional sprints, the siren song
of endurance racing was too much to resist and we began our sojourn
to Hades.
Endurance racing, even on the pathetic scale on which we practice,
involves resources which are counted on lists entitled: Dollars,
Bodies and Tasks. These lists come to rule our lives.
The first list quickly added up to $24,000 including most of our
racing expenses such as building the bike, maintaining the bike,
transporting the team around the country, tires, consumable supplies
(ie. body work and pistons) and the many fees to be paid to track
owners, sanctioning bodies and often, state police departments.
This included the sponsorship we receive from Battley Cycles (310)
948-4581 and PDI (301) 776-2271 without
whose help we would never even consider building superbikes.
After the grim reality of that figure had permeated my soul I
set to finding similarly addicted racing junkies who were willing
to commit liquid assets to this existentialist pastime. I didn't
have to search far as 1994 Army Of Darkness rider John Donnelly
was just about to throw $8,000 away on his son's future college
education and AOD reserve rider Jim Williams was going to spend
$8,000 having the valves on his Ducati adjusted. I figured I could
come up with my share of the cash eventually.
Next was the Bodies list. My long suffering pit crew of many years
Tim Gooding and Amy Pickering volunteered their hearts and souls
and Deb Donnelly figured that she hadn't seen John auger in for
a year and her best chance to witness that event would be to round
out our pit crew. Six people (three rider, three non-coms) is
about the bare minimum of warm bodies needed to run an endurance
event (including the all night drive to the venue) but I figured
other victims would materialize for a race or two.
The last list comprises of all the individual tasks which must
be finished before the season begins. Its doesn't help much that
sanctioning bodies tend to float their schedules a bit so that
the first race of the year in late April in North Carolina becomes
March 30th in Las Vegas, Nevada forcing everything
on the task list to compress.
A sample of our task list reads:
Task Who Hours
Strip bike and motor Sam & Tim 8
Measure everything in motor Tim 4
Make a pot of coffee Sam .25
Port head Tim 35
Spray paint frame Sam .1
As the team owner I accept the responsibility of drawing up the
task lists.
Army Of Darkness is perennially perceived as the underdog. This
status is difficult to maintain when the team is successful (usually
in cherry picking regional races) but the impression is facilitated
by using Yamahas as our donors. Yamaha does their best to get
us to switch brands by:
1 Spending more on a single Royal Star TV ad than their US racing support.
2 Their gooney engineering and quality control leaves us with lots of extra work.
3 Their bikes are about three years behind the times and when they finally put down the air brush long enough to build a competitive machine they don't export it to us.
4 They pay more contingency money to supersport racers rather
than superbike racers (which does have a certain logic if you
consider the likely hood of anyone winning a supersport race on
a YZF)
The previous owner of our particular machine had used it as a
supersport racer. As such we figure it would be reasonably stock
once the bolt-ons were removed. We were very wrong.
Tired of flogging the dead horse this plucky fellow tried to have
the motor revived with a few tricks, all of which were designed
to increase power and be relatively stealthy in terms of a supersport
tear down. The first item which tipped us off was a non-factory
finish on the cam journals in the head. The cam caps were left
stock (for the tear down) but friction reducing additional clearance
was ground into the head. The next illegal spot was the porting
on the inside curve of the intake tract. 50% of head porters (ourselves
included) think this is a crucial spot for flow through the head
and it was done in such a manner that only by using a dentist
mirror or pulling the valves could an inspector have found the
modifications. The most blatant violation of supersport rules
was the machined finish on the cylinder to case mating surface.
There is no telling how much material had been removed but the
top of one of the bosses for the alternator cover had been partially
machined flat. An observant competitor could have spotted this
and safely protested with a full motor teardown.
We found these liberties, along with a cracked motor mount on
the frame, with some mixed feelings. Although the modifications
had not actually improved the performance of the bike (we saw
the before and after from the dyno runs) the rider from whom we
had purchased the bike had always garnered a fair amount of respect
from us through his talent, results, and recently, his improved
interpersonal skills. Not only did we feel a little burned (as
we had asked if there was anything wrong with the bike or if anything
had been done to the motor internally) but also that a rider of
his stature would feel compelled to cheat. It may just be a commentary
on Yamahas but it seems that the notion of affordable, rule following
supersport racing is naïve, especially with prize money at
stack. Although we knew that other Mid-Atlantic supersport racers
crowing about their wins were cheating out the wazoo, it was still
a disillusioning experience for us.
The YZF's racing advantage, from our perspective, was that we
could buy parts from Battley Cycles at a steep discount. This
being the case we set to rectifying, to the best of our abilities
(and finances) the bike's plethora of weak points. Tim's job of
making a competitive machine is made harder by the fact that I
am a dog slow rider. If I can extract 90% of a machine's potential
then Tim's bike has to be 12% better than the bike's piloted by
the individuals who can extract 100%. This ratio will allow us
to win, by a slight margin.
After perusing the machine Tim decided that:
These projects have a way of compounding.
The material problem with the frame was its color. We hung the
bike up from the rafters in the garage, poked it with air wrenches
and periodically shook it on its chains until all the pieces where
on the floor. We deposited the motor on the most easily cleaned
workbench for further surgery and warmed up the spray cans for
the frame and swingarm.
One theory of chassis set-up is to start with the tires and work
one's way up. Our choice for tires was very easy. Michelin has
got a zillion different slick compounds and constructions all
in the 180/17 size. This dictated a switch in rear rims from the
stock 5.0 X 17 to 5.5 X 17. The first time we considered trying
Michelins was 1994. Walt Schaefer told us that we could run a
4 hour race on one set of his softest tires. We thought he was
blowing tire salesman smoke in our faces and bought a set of Metzlers,
only to slither around a chilly Road Atlanta for four hours. In
1995 I was sprint racing and tried a set of Dunlops on the FZR
560 Tim had built for me. The tires delivered great grip but were
shagged in about three hours of track time. I was not going to
spend $2,500 on tires for a season of sprint racing so I finally
bought a set of Michelins from Walt and promptly ate my unspoken
doubts. They lasted twice as long as the Dunlops and were every
bit, if not more, as grippy as anything I'd ever used. Although
we have found it almost impossible to wear out a set of Michelin's
softest tires in less than eight or nine hours we thought that
the variety of harder tire choices offered by Walt may come in
handy.
In previous years we have wasted precious track time sorting out
the spring and damping rates in newly built motorcycles. We usually
end up getting it right but the experience is frustrating. In
an attempt to leap frog up the learning curve we contracted out
the suspension set up to Lindemann Engineering. The YZF forks
are notoriously cheap inside and we hoped that Lindemann would
be able to neutralize any advantage the ZX-6 or F-3 held over
us in the fork department. The shock is a standard issue Fox which
LE reworked to match the front end. In truth the whole thing made
me a little nervous as ignorance of equipment modifications has
bitten many a racer in the butt, however, my ignorance of the
inner workings of motorcycles becomes more evident to me every
time we take one apart so I've learned to live with the anxiety.
The YZF has got Nicasil liners on its cylinder walls. The cynical
would surmise that Yamaha went this route, not for better heat
transfer and longer wear, but to go to any lengths to avoid having
to tool up for radically different cases and crank spacing. The
FZR 600 is based, to an appalling degree, on the FZR 400. The
cases are almost identical. The YZF shares many of the same dimensions
with the FZR although the cases are thicker, the transmission
bearings are bigger (as are the shifter forks and a few other
pieces) but the crank journal spacing remains the same as the
original 400. In order to achieve a slightly more over square
design than an ocean going diesel, Yamaha decided to enlarge the
bore 2mm from the FZR 600 to the YZF 600. The only problem is
that the original FZR 600 was bored as big as it could get in
the first place, there is simply no more room for cast iron liners
between the cylinders; Big bore kits have very short life expectancy
in the FZR because the liners have to be wafer thin. Yamaha's
solution: ditch the cast iron liners, bore it out a bit more and
plate the cylinder block itself, then cover up the parsimonious
engineering by drawing the public's attention to the cylinder
liner rather than the cylinder itself. Bastards.
The Nicasil would also eliminate increasing displacement through larger pistons, so we took a note out of our FZR 560 and we stroked it instead. We sent off an extra FZR 600 crank down to Falicon and had them destroke it 1mm. This gave us a displacement of 649.7cc. The class limit being 650cc. I hoped the tech inspectors have accurate micrometers. Falicon also reworked the rods to make them less prone to stress fractures. The biggest challenges to fitting the older style crankshaft were the process of fitting an ignition and alternator. The sealing surface of the FZR crank is a smaller diameter than the YZF. Jeff made a steel ring to take up the extra clearance. The next challenge was fitting an FZR ignition to a YZF wiring harness. The YZF harness has 14 wires for the ignition box, the FZR has 9. Tim decided that was my problem.
The stroke job was not quite as complicated as on the 560 as this
time we did not have to make new cast iron liners to accommodate
the additional stroke. Jeff Manuel (our team machinist, everyone
should have one, they are really very useful, if you would like
to borrow ours you can call him at the PDI number above) made
four aluminum spacer plates to accommodate the longer stroke.
These spacer plates varied in thickness so we could tune the compression
ratio as needed as a later date. The transmission, despite some
dimensional improvements, still had the crap press fit bushing
and harley style clearances. It would simply not do.
Jeff and Tim learned to fortify transmissions from an article
published in RRW. The Yamaha transmission utilizes the Japanese
philosophy of good design and poor execution. They figure that
extra design work costs less than spending an additional five
dollars per transmission. As such the stock bushings in the gears
are a soft metal with a seam and a light press fit. The clearances
between the bushing and the tranny shafts are much larger than
they need to be and this allows the gears to move in more planes
than one. In extreme cases the gears can touch each other when
they are not supposed to resulting in catastrophic failure of
the transmission. After the clearances have been tightened up
(by machining new bushing out of a much fancier bronze) the gears
are then shimmed to more exacting tolerances to prevent excess
gear wiggle and more positive engagement. We do not undercut gears
for two reasons, we can't do it easily and often shifter forks
are holding the gears in place, undercutting can apply the power
of the motor sideways onto the shifter fork. This is not conducive
to equipment longevity.
It sometimes seems that the riders are pitted against the mechanics.
The riders try to wear out the equipment faster than the mechanics
can build it, Freddie Spencer comes to mind. In just such a misguided
contest one of our riders tried to waste the transmission by crashing
onto the shift lever. Since the motor continued to function normally
we, in blissful ignorance, continued on with our season. When
we tore down the motor at the end of the year we found severe
wear on one gear and shifter fork. The shifter fork was bent in
the accident but the transmission never failed because the tighter
clearance kept the dogs apart. Had we been using a stock transmission
we would have most certainly been shopping for new crankcases
instead of a gear and shifter fork. Even after that experience
I probably still won't strip motors down everytime they get a
bent shift lever but it might not be a bad idea. I'm not sure
if I would feel relieved or bitter after stripping a post crash
motor only to find that everything was in tip-top shape.
Even after strengthening the transmission we felt it was unwise
to place unnecessary pushes and pulls on it, unfortunately Performance
Machine doesn't feel the same way. Tim likes PM wheels for their
shiny finish and polished welds. PM, however, primarily manufactures
shiny bits for the boulevard crowd and, as such, does not pay
much attention to the applications to which racers employ their
products. This means they don't fit cush drives to most of their
rear wheels. This is bad.
Every power pulse produced by the motor briefly accelerates the
crank, which, in turn accelerates the clutch and transmission
shafts. The pulse then travels down the length of the chain and
tugs on the sprocket which yanks the tire forward. After the power
in the pulse ebbs the tire is given a brief respite, and various
forces act on it to actually slow it down a little. At some point
(how long depends on the architecture of the engine) the next
pulse is generated which accelerates everything again. The tire,
between power pulses, actually has a little time to recover between
pulses. The longer the recovery time the less prone the bike it
to high siding. Thus the development of "big bang" fours
and the tremendous drive many twins enjoy at the exits of turns.
These pulses also cause gears in the clutch and transmission to
jar and snatch which does them no good at all. The stock cush
drive is there to soak up some of the violence in this action
and allow the components to enjoy some sort of life expectancy.
Many a wheel swapper who has omitted the cush drive has fatigue
cycled the sprocket bolts into oblivion.
Tim loves this sort of phenomena and set to designing a cush drive
which would bolt onto a stock PM wheel and accept a commercially
available sprocket. The secret lies in the press fit Metalastic
rubber bushings. The Metalastic bushing representative became
very helpful when Tim let it be known that he was calling about
power transmission damping and he was calling from the Smithsonian
Institute. Smelling a fat goverment contract our intrepid regional
representative compiled a very reassuring looking binder filled
with military applications for their products. As they are a subsidiary
of Dunlop we can only hope that their rubber bushing last longer
than their tires. His piece will bolt up to any PM wheel that
accepts PM sprockets which allows us to use them on any wheels
we may require. This satisfies his desire to not have lots of
parts to roll away during tire changes and my desire to have options
if anything untoward should happen to the cush drive. The use
of a commercially available bolt spread on the sprocket allows
for easy access to lots of gearing choices. Tasty.
Applying our intake gas speed formula previously published in this periodical in earlier AOD articles:
| (((((B/2)*(B/2))*(PI)*S))/((V*(PI)*L)*v#)*((RPM/2)/60))/100 | |||||
Where: B = bore
S = stroke
V= valve size
v# = number of intake valves per cylinder
L = peak intake valve lift
RPM = revolutions per minute of the crankshaft
PI is approximated at 3.141593
We calculated the gas speed for the YZF in various configurations.
This yielded the following chart:
| 1990 | 1991 | 1994 | 1994 | 1994 | 1994 | 1994 | 1994 | |
| INPUT: | FZR 600 | CBR 600 | YZF 600 | YZF 649.7 | YZF 649.7 | YZF 649.7 | YZF 649.7 | YZF 649.7 |
| Bore (in mm) | 59 | 65 | 62 | 62 | 62 | 62 | 62 | 62 |
| Stroke (in mm) | 54.8 | 45.2 | 49.6 | 53.8 | 53.8 | 53.8 | 53.8 | 53.8 |
| Lift (in mm) | 7.75 | 8.1 | 7.75 | 7.75 | 8 | 8.25 | 8.5 | 9.0 |
| Valve size (in mm) | 24 | 25.5 | 25 | 25 | 25 | 25 | 25 | 25 |
| # of Valves | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| Redline | 12,000 | 13,300 | 13000 | 12300 | 12300 | 12300 | 12300 | 12300 |
| Target Peak Power RPM | 11,700 | 13,000 | 12,750 | 12,000 | 12,000 | 12,000 | 12,000 | 12,000 |
| Calculated: | ||||||||
| Displacement | 599 | 600 | 599 | 649 | 649 | 649 | 649 | 649 |
| Piston Speed(m/min) | 1315 | 1202 | 1289 | 1323 | 1323 | 1323 | 1323 | 1323 |
| Piston RPM limit | 12,515 | 15,173 | 13,827 | 12,747 | 12,747 | 12,747 | 12,747 | 12,747 |
| Gas Speed @ Redline | 128 | 128 | 133 | 137 | 132 | 128 | 125 | 118 |
| Gas Speed @ Target RPM | 125 | 125 | 131 | 133 | 129 | 125 | 122 | 115 |
| Gas Speed At RPM | ||||||||
| RPM | ||||||||
| 1000 | 11 | 10 | 10 | 11 | 11 | 10 | 10 | 10 |
| 1500 | 16 | 14 | 15 | 17 | 16 | 16 | 15 | 14 |
| 2000 | 21 | 19 | 21 | 22 | 22 | 21 | 20 | 19 |
| 2500 | 27 | 24 | 26 | 28 | 27 | 26 | 25 | 24 |
| 3000 | 32 | 29 | 31 | 33 | 32 | 31 | 30 | 29 |
| 3500 | 37 | 34 | 36 | 39 | 38 | 37 | 35 | 34 |
| 4000 | 43 | 39 | 41 | 44 | 43 | 42 | 41 | 38 |
| 4500 | 48 | 43 | 46 | 50 | 48 | 47 | 46 | 43 |
| 5000 | 53 | 48 | 51 | 56 | 54 | 52 | 51 | 48 |
| 5500 | 59 | 53 | 56 | 61 | 59 | 57 | 56 | 53 |
| 6000 | 64 | 58 | 62 | 67 | 65 | 63 | 61 | 58 |
| 6500 | 69 | 63 | 67 | 72 | 70 | 68 | 66 | 62 |
| 7000 | 75 | 67 | 72 | 78 | 75 | 73 | 71 | 67 |
| 7500 | 80 | 72 | 77 | 83 | 81 | 78 | 76 | 72 |
| 8000 | 85 | 77 | 82 | 89 | 86 | 84 | 81 | 77 |
| 8500 | 91 | 82 | 87 | 95 | 92 | 89 | 86 | 81 |
| 9000 | 96 | 87 | 92 | 100 | 97 | 94 | 91 | 86 |
| 9500 | 101 | 91 | 97 | 106 | 102 | 99 | 96 | 91 |
| 10000 | 107 | 96 | 103 | 111 | 108 | 104 | 101 | 96 |
| 10500 | 112 | 101 | 108 | 117 | 113 | 110 | 106 | 101 |
| 11000 | 118 | 106 | 113 | 122 | 118 | 115 | 111 | 105 |
| 11500 | 123 | 111 | 118 | 128 | 124 | 120 | 116 | 110 |
| 12000 | 128 | 116 | 123 | 133 | 129 | 125 | 122 | 115 |
| 12500 | 134 | 120 | 128 | 139 | 135 | 131 | 127 | 120 |
| 13000 | 139 | 125 | 133 | 145 | 140 | 136 | 132 | 125 |
| Army Of Darkness - Ministry of Research |
A discussion of how we employ the above formula and graph has
already been published twice in this periodical but, in brief,
we aim for 125 at about redline or shortly before. The first three
columns show the numbers for stock motor; the third column for
a stock YZF. You can see that they were stacking the power a little
low for most racing application. The situation gets worse if the
displacement of the engine is enlarged (column four) although
the full effects of the displacement increase are not felt since
the redline for a longer stroke motor has to be reduced. Columns
five through eight show the effects of different camshafts. Not
all of these cam lifts were available to us so we went with the
8.5mm shown in column seven.
There is really only one outfit that modifies motorcycle camshafts
in this post-industrial country. This situation is to their benefit
as they can misplace camshafts, ignore their own deadlines and
blame the customer for the shop's disorganization yet not suffer
any loss of business since the next closest motorcycle cam shop
is in Britain. After much confusion and hubris the cams finally
were delivered four weeks late. We happily broke out the dial
indicator and degree wheel only to find that there was welding
flux and other unidentified spooge caked into the oil holes. Tim
and I exchanged nervous glances as we looked at the crooked plugs
inserted into the cam ends and the bead blasted surface. The glass
beads used in bead blasting have an insidious nature. They tend
to lodge themselves in the metal on a microscopic level and then,
after a couple of hours in a hot warm oil bath, work their way
free and set to enlarging clearances by rapidly wearing away metal.
Many a restoration project has been lost to the temptation of
the shiny bead blast finish.
This being the case I figured they must intend for us to clean these somehow before installation although with the oil galley plugs installed it would certainly be hard to get any sort of brush into the center of the cam. I called up the manufacturer for a little advice on proper preparation before installation. "Don't clean the cams, we cleaned them before we shipped them and if you clean them you will wash the protective oil coating off" she said as I picked flakes of black crud out of the conspicuously unoiled journal holes with my pinky nail. "I see, yes, but, ummm, there seems to be lots of black crud in the oil journal holes." I ventured cautiously. "If you feel the need to wash them then you can use solvent" was the helpful reply. Honestly, sometimes I think it would just be easier to learn to ride fast.
It would seem from this experience that the lore of unreliable
motors stemming from camshaft modifications has nothing to do
with lobe dimensions, RPM and inertia but rather the ignorant
and indignant who supply the kit in the first place. It would
seem that unless you have access to a large ultra-sonic cleaner
it may be best to just stick with the clean, oily cams that came
out of the motor in the first place. The other explanation is
that the bead and the crud supplied with the cams were secret
high tech abrasives which will actually lap the cams into the
head to a prespecified clearance freeing up lost horsepower and
then dissolving harmlessly into the oil. In all fairness they
did do a mega-nice job of repairing a sprocket mounting flange
which was broken when the cores were shipped to them.
After spending many unhappy hours rejetting CV carburetors we decided to treat ourselves to a set of bonafide racing carbs and purchased a set of FCR flatslides. The 33mm carbs would have bolted straight up to the bike but the 35mm were on sale so 35mm it was. Tim took the appropriate action to, not only get the carbs to bolt up to the bike, but to work with the stock throttle cables. Tim is usually busy enough at the track without having to clean gravel, grit and little balls of rubber out of the carbs or head after each off track excursion so he made up a pair of free flowing filters to cut down on the motor's ingestion of rubber and rocks.
It is about this time in a project that the ulcerous doubts begin
to materialize. Every action is crucial to the finished product
and yet tedious and time consuming. Quickly one comes to the end
of the known quantities, the known values and the known strengths
of materials and have to venture into the uncharted wasteland
of desire and doubt. We decided to assemble the bike with a moderate
compression ratio of 12:1 with the thought that if we felt we
needed more power we could go back and raise it later.
After the ubiquitous late nights we trundled off to the dyno room
at Battley Cycles and strapped the bike down. Chris Sanders, resident
tuner and long time AOD skeptic, gracefully allowed us to break
in the bike for a half hour and kindly ignored various pieces
which vibrated off onto the floor. He was also benevolent about
our unique aluminum battery box/electrics tray. Remember many
street signs are aluminum sheet. Use your environment.
Then the tests began in earnest. Despite bad cam timing, the wrong
intake tract length, an exhaust pipe designed for another application
(street riding) and jetting for a ZX-6, the bike made about 100bhp.
Revisions to the cam timing, intake tract length and jetting raised
the peak power slightly but made big increases through the power
band. This was a 25% increase in power over the bike's stock incarnation.
At first I was a little dismayed at the low figure for peak power.
It trails off early and doesn't really rev out like one would
expect. A doubt then pipped up and said "Yamaha's are cheap
pieces of junk and you just increased the output 25%. How long
do you really think this thing is going to stay in one piece?"
I put that thought out of my mind with visions of our reworked
rods and we loaded the trailer and set off west to Las Vegas.
On the track:
If the point of racing motorcycles is to induce emotional extremes
in an otherwise sanitary, strip-malled and sub-divided post industrial
society, our first weekend of 1996 was a thorough and utter success.
The 36 hour drive from D.C. to Vegas was relatively uneventful.
The relatively being the comet visible in the sky and a seized
emergency brake cable with resulting white smoke. To paraphrase
Walt Schaefer "If you can't field strip your transporter,
you're in the wrong sport."
Repairing the brakes (snipping the offending cable with a pair
of bolt cutters) did not consume enough time and we had to rock
climb in Red Rocks (outside of Vegas) for a few days before the
track opened. There are not many obvious crossovers from rock
climbing to road racing. There are a few experiential similarities
(fear, pain, sweating) but the techniques could not be more disparate.
However, a common mistake to both pursuits is over gripping. No
matter how strong one is, using 100% of one's grip will quickly
render one's forearms useless. In rock climbing, as in road racing,
it is important to not hold on tighter than necessary. Of course,
as soon as I get nervous this axiom is quickly forgotten. While
Tim, Amy and I scared ourselves in the desert, John decided to
take the van for a few impromptu practice laps of the track before
a speedway official pointed out the exit for him.
Either the NASB event scheduled on the same weekend detracted
from attendance or would be participants were distracted by the
legalized gambling and prostitution nary 75 miles away. The desert's
lonely beauty was certainly not compromised by excess corner workers.
I have never seen a race, much less a national, so lightly cornerworked.
A pair of errant soft ties lay in a corner for the entire day
as no one could be bothered to walk over and retrieve them. The
track does have the most ample run off of any motorsports park
road course I've ever seen so practice went off without a hitch,
at least for the other teams.
Field stripping transporters: no problem. Diagnosing troubled
race bikes: completely gormless. Halfway through the day we lost
one cylinder. After checking the plug, plug cap, coil, jets and
compression, repeatedly, to no avail, one of us thought to check
if the slide was opening on the recalcitrant cylinder. It was
not. The set screw which attached the slide to the throttle shaft
had backed off leaving the slide to remain in its default, closed,
position. Having never had a bike with flatslides it never dawned
on any of us that an independently minded slide not could be a
problem, much less the problem. These mechanical shenanigans
sufficed for practice time and we made do with a evening stroll
around the course, a watchful eye kept for the dragracing cops
using turn one as a cool down stretch.
The walk proved fruitful and during raceday morning practice Jim
cut five seconds off of his previous best. John and I wondered
if we would be able to match his times. Taking notes from Jim
(and a passing 125) I followed suit and got down to 1:22. Due
to schedule changes we deprived John of any meaningful practice
before the start of the race and his fastest lap stood at 1:25.
We knew that the sprint 600s could run 1:17 and we (being slow
neophytes to this track) were aiming at 1:21. We were able to
determine from our brief track excursions that the suspension
was very good, the tires even better and the track's grip had
improved measurably from the day before. Jim and I compared notes
about gears and lines and fed everything upon which we agreed
to John, who was going to have to race cold.
An eastern hiking maxim referring to ground dwelling yellow jackets
is "The first wakes them up, the second gets them angry,
the third gets stung."
With this in mind I voted myself first rider. Gridded on the 13th
row and never having before launched this bike (but having scared
myself silly with Yamaha clutches in the past) I was not overly
aggressive at the start and thus didn't get a very good view of
the unfortunate rider who crashed in turn three on the first lap.
I took a lap or two to scrub in the new tires and then set off
in pursuit of the departing pack. The times on my lap board steadily
dropped down to the low 1:21 high 1:20 area. As I was passing
bikes at a reasonable rate and didn't want to tire my dainty hands
too early in the race I grew complacent at those times although
I think more than one 750 rider was discouraged by the black tail
section creeping by on the two short straights.
John was next out. Depriving him of practice seemed to have no
ill effects and his first few laps were quick. His determined
body language and 1:20 lap times made me inquire of my teammates
as to John's current marital bliss.
The first hour results had us listed as 14th overall
and 1st in class. This was in error since WERA had
listed a middleweight superbike team in another category. We where
actually 2nd in class. It was better than I thought
we were doing so I was pleased as I watch John pick off a couple
of more heavyweight teams and move us to 11th overall,
2nd in class.
However, I woke them up, John got them angry, Jim got stung. We
all knew something was wrong the first lap Jim took. His lap times
were two seconds slower than his practice times. This did not
bear well. Every now and again he would do a couple of 1:21s but
we could all see he was not pleased with something on the bike.
An hour into his stint, and reminiscent of the breakfast scene
in Alien, the bike coughed twice up the front straight
and expectorated a connecting rod through the front of the motor.
The location of demise could not have been better as it allowed
Tim a perfect view of chunks of crank case tumbling down the track.
Jim's motor failure instincts, honed from years of racing two-strokes,
pulled in the clutch, stuck out a foot and nailed the brakes bringing
the bike to a halt on the gravel outside of turn one. He could
smell the Motul burning on the exhaust pipes and knew there must
be oil on the track. With visions of becoming a track pariah he
frantically signaled to the teenaged corner workers but three
laps went by before the red flags came out.
A quick post disaster inspection showed that, even with the oil lost to the front straight, the oil level was still visible in the oil windows. We were later informed that the red flag was thrown, not for oil on the track (which was apparently minor after all), but for fear of tire punctures cause by our wayward engine parts deposited on the front straight.
There didn't seem like much else to do but pack our gutted machinery and slink back east, tails firmly ensconced between our legs.
At the track we suspected one of Yamaha's famed weedy connecting rods had caught us out but the autopsy revealed our $1,000 crankshaft had broken its number one connecting rods journal which made life very hard on the bearing. Eventually the bearing was pounded to leaf and the rod bolts backed off causing the catastrophic failure. It turns out that ours was not the only YZF to fail that weekend leaving us is a bit of a quandary as to an appropriate motor configuration. One might be able to play it fast and loose with the rules of WERA but one can never take liberties with the law of entropy.
