Great account of your "test session" Doug!
Thanks, John 309A/F Dragster (ex.)
----- Original Message -----
From: <ARDUNDOUG@aol.com>
To: <land-speed@autox.team.net>
Sent: Monday, December 18, 2000 2:12 AM
Subject: Ardun Dragmaster Test Session #2
> Crew, Friends, and the LSR List,
> Since this update is going out to a wide variety of people please bear
> with me. While this dragster isn't an LSR car, it is the test bed for the
> powerplant we plan on eventually running in the King$ Ran$om XXF Modified
> Roadster.
> This car, a 1600 lb.(with driver) 120" wheelbase replica of the 1960's
> Dragmaster Dart front engine rail, is powered by a 258ci (3 5/16" X 3
3/4")
> 1949 Ford Flathead V-8 with an Ardun overhead Valve conversion. Induction
is
> a 4:71 GMC blower running at 16% overdrive on a homemade manifold. The
fuel
> used is Methanol.
> In November Son Brian and I tested the new combination at Sacramento
> Raceway, making a 132/10.3 pass (mine) and a 144/9.6 pass (Brian's) before
a
> fuel leak put us on the trailer.
> Yesterday we again traveled to Sacramento to continue the R&D with the
> help of Bonneville Speed Week crewmembers Mike Gorvad and Elon Ormsby.
This
> time we richened the main bypass from the Gene Adams suggested .130 to a
> .115, leaving all other tuneup settings the same.
> On the first pass Brian experienced considerable handling problems in
the
> first half of the track, lifting off of the throttle 3 times, and turned
> 155/9.2. On the second pass we changed the tire pressure slightly and
Brian
> made a strong, straight pass, showing 160/8.84 on the sign board at the
end
> of the quarter mile. From the starting line I heard the engine backfire
> loudly in the timing lights, then backfire and "pop" continuously through
the
> turnoff at the end of the shutoff area. By the time we reached him he was
out
> of the car and waving frantically while pointing to the front of the
engine,
> which was missing the blower snout and front gear housing of the 4:71.
> Worrying about the starter sending race cars down the track with our
> blower debris scattered along the route, Elon jumped into the chase truck
and
> roared back to the starting line to alert the officials.
> We found the first pieces of the blower front gear housing about 50'
> before the finish line and the blower snout, shaft, and Gilmer belt gear
> about 200' past the finish line.
> Brian later recalled that the last time he looked at the tach it was
> between 6900 and 7000RPM, about 170MPH on the "dream-wheel". Evidently,
just
> before the end of the 1/4 mile the upward force on the Vertex mag pushed
it
> out of the grip of the slip-ring that is clamped to the front engine
cover,
> retarding the spark about 30 deg. This caused a blower backfire which
stalled
> the blower rotors when the burst-plate on the back of the blower manifold
> bulged but didn't rupture as designed. The 2"-8mm drive belt was stronger
> than the cast aluminum blower gear housing, which failed and gave Brian a
> face full of 90w gear oil at about 170MPH. The 10lb blower snout, shaft,
and
> belt pulley then bounced off of the cam driven injector pump, hit the
ground,
> massaged three of the left side headers, and passed under the rear of the
car
> while doing a number on the bellypan.
> After cleaning up the car today and testing the vital signs I've
decided
> to pull the engine, add some valve spring pressure, get the blower checked
> and have a different design of "pop-off" built by my "go-to" guy in
> Sacramento, Mark Hall, and fabricate a support from the blower snout down
to
> the manifold. The 5" snout evidently puts too much strain on the GMC front
> gear case.
> All-in-all it was a good test session. Brian said that he'd never felt
> anything like the "kick-in-the-pants" that blower gave him at the top-end.
> With the short wheelbase Dragmaster we'll never get the results we got
with
> the bigger normally aspirated Ardun in the first 1/8 mile of the track.
The
> second 1/8 mile was evidently pretty awesome.
> Our plan is to get the chassis and headers repaired, freshen-up the
> engine, check the blower, fabricate a snout support, replace the broken
> blower housing, and possibly complete the testing later next year in
> preparation for running the blower at LSR events in 2002.
> For 2001 it looks like the plan is to get the John Kilgore close ratio
> gears installed in the C-4 this winter, install the backup Fuel Ardun in
the
> Modified Roadster for Muroc (If it becomes a reality with SCTA), and
> hopefully have the Jimmy Stevens inspired Ardun ready to run for the El
> Mirage XXF/GMR record in May.
> Jimmy feels that we can go 200MPH on gas with King$ Ran$om at
Bonneville
> and is calling the shots on the engine to make the attempt with.
> Ardun Doug
King
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