PROPWASH
April 2013
5
2013 West Texas Shootout for Autism Awareness
By Jay Stone
Race Contest Director
It will be a warm spring day in
the little Ol’ West Texas town of El
Paso, and racers will once again
gather to find out who are the
baddest hombres north of the Rio
Grande. Racers from California,
Arizona, Colorado, New Mexico and
Texas will battle it out at high noon
in April 2013.
Only a few were left standing, and those that remained were crowned Shootout
Champions for Autism Awareness in 2012. Do you have what it takes to line up next
to some of the greatest racers north of the Rio Grande?
The 2013 West Texas Shootout for Autism Awareness will take place April 26-28,
2013 in El Paso, Texas. This will be the third annual running of this event. We have
watched the list of competitors grow each year and, as a result, the level of competition
is second to none.
Open water will take place on Friday, April 26 from 7:00 am until 4:00 pm
Mountain Standard Time. At 4:00 pm, racers will kick off the event with the Team
Marathon Class which will pit seven teams of four against each other. Two drivers,
two G-1 Monos, and two pit persons per team will duke it out over 100 laps of racing.
Once the Marathon event is over, the water will re-open until 7:00 pm.
Racers will then gather for a social event at Bart Reed’s Comic Strip at 8:30 pm.
The Hampton Inn and Hawthorn Inn host hotels will offer shuttle service for guests to
and from the Comic Strip. Main classes of racing will kick off at 7:30 am sharp on
Saturday, April 27. Drivers meeting will take place just prior at 7:15 am. The start
times will be the same on Sunday.
The event will be a NAMBA District Seven sanctioned event and will follow the
District Seven’s class schedule. G-1 classes will participate on Saturday (G-1 Mono,
G-1 Cat, G-1 Sport Hydro, G-1 Rigger, Crackerbox, Jersey Skiff, Novice/Rookie,
P-Spec Tunnel, and P-Mono). On Sunday, we will run our Open G classes which
encompasses all G-1, GX-1, G-2 and GX-2 engines in the same class (Open G Mono,
Open G Cat, Open G Sport Hydro, Open G Rigger, Twin Gas Class, Classic
Thunderboat, P-Spec Rigger, and LSH Sport Hydro).
We also offer two unique trophies for our event. The Eli Karagich Award for
Excellence is awarded to a racer who exhibits a dominating performance over the
weekend of racing. Dale Roberts won this award in 2011 and Robert Holland took
home the honors in 2012. District 19 and District 7 also compete in a shootout between
the districts in which points are gathered for each district through heat racing and
shootout classes. The winning district takes home “ARMY the Armadillo” shootout
trophy. District 19 took home the honors in 2012, but District Seven is gearing up to
bring Army back home in 2013.
While this race is a shootout event, the format is based off of regular heat racing
point totals. The top six for each class is placed into a Winner-Take-All shootout final
that earns a unique shootout trophy and bragging rights. Our trophy girl, Samantha
McCardle, will also be attendance once again this year!
Racers will gather for a group dinner Saturday night at 7:00 pm. Location of this
event will be announced by the time this newsletter goes to print. We are looking at
adding live music, along with great food and adult beverages. Once again, the host
hotels will offer shuttle service to and from dinner. In 2012, we gathered at Bikini
Joe’s restaurant and had a great time. Racing and competing at high levels is always a
rush. Racing and having a blast with other racers at organized social events makes for
a great weekend. Combining those aspects with the fact that proceeds from this great
event will be donated to the Autism Society of El Paso is a win-win for all involved.
Continued on page 6
Preliminary testing on a 50 cc motor-
cycle engine looks good. The intake
valve into the crankcase is another point
of complexity and restriction in two
strokes. Many valve schemes have been
tried with piston ports and disk and shaft
rotary valves favored by model engines.
Larger engines mostly use piston ports,
reed valves, and disk valves. Except for
starting, why do two strokes need
crankcase valves at all? It turns out that
the crankcase acts as a Helmholtz
resonator driven by the pulsations in the
cylinder. Crankcase pressure rises and
falls, drawing air into it without valves.
Frits Overmars has described a reed
valve system that acts normal at low rpm
but can be opened completely at higher
rpm, creating an open hole into the
crankcase. He calls this the 24/7 intake
system illustrated below with an early
prototype.
David Wilfong has removed the disk
valve in a CMB nitro engine and run it
successfully with no intake valve.
Whether it develops more power is still
to be tested.
It’s difficult to get a reed valve to
work in a small engine at the very low
crankcase compression ratio that’s best
for the 24/7 system. A big disk or rotary
valve only sacrifices a little peak power
in simulations to the 24/7 system in a
FOS style cylinder.
To take advantage of the huge time
area the FOS scavenging allows, the
engines need to run at high rpm. This
could be over 30,000 rpm in a 26 cc
engine. Doing this requires cutting edge
mechanical design with the right
bearings and materials. That will be
covered in part 3 of the
October 2013
Propwash.
24/7 Reed valve