Prior to the 2002 Laughlin Tandem Wing fly-in, John Mason built
this engine test
stand for me, using plans I drew up. John was kind enough to
temporarily donate
his trailer to the task of toting the rig around.
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The design allows for the installation of most any engine.
the engine mount shown is for a Corvair engine on a Quickie Q-2.
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Click image for a larger version.
After clicking the link, be sure to view it full size.
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Here's my
102hp YN engine being used as a static display at the 2002
Laughlin Fly-in. This engine has not been run yet, and
when this photo
was shot, the stand wasn't quite ready to run an engine. A year
later, it was a different story. |
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John Moyle had an engine which needed to run and had a trailer
which could be
kept connected to the test stand, so we got the engine running,
finished up the test stand with a Dragonfly FWF and had a running engine at Laughlin 2003!
You may have noticed that the test stand allows for the engine to be
located in two different positions; one for towing and one for running the engine.
In the event that the reason for this is not obvious, I'll explain.
With the engine in the high position the firewall shields the operator from most of the prop blast.
With the engine in the lower position, the CG of the rig is lowered and the frontal area can be hid behind the tow vehicle. Both of these "features" assist in towing comfort.
The first year I towed it to Laughlin, I didn't have any help with lowering the engine before I departed. I used my 2600cc mini-truck to tow the 1500-2000 pound rig, and with the wind resistance working against me I could hardly do 50 mph. With 400+ miles in front of me, 50 mph just wasn't going to cut it.
As I approached the freeway I remembered that there was a tire store on the way so I popped in and asked for some help. We lowered the engine in no time flat and I was back on the road doing 70+ with minimal effort. Lowering the engine makes a BIG difference if you don'
t have surplus power to waste. |
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This is the back side of the firewall, where the dual MSD coils
live, as well as the
required ballast resistors, and the MAS coil joiner.
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Here's a view of the underside, showing the headers I built. |
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Bendix/Zenith side draft carb.
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We ran the engine several times over the weekend.
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Click image for a larger view
With the stand hitched to John's Ford Explorer, it was just TOO
tempting to kick it out of gear and push it around the airport!
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Front shot showing the inside of the cooling tin which have become
affectionately known as the "mail boxes".
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This view clearly shows the remote oil cooler and filter. |
The control panel of the engine stand. The Facet pump picks up filtered
fuel from the fuel tank. Pressurized fuel is then plumed through
a pressure regulator which drops the pressure down to 1-2 psi.
A fuel pressure gauge is plumed after the regulator. A 12v battery
lives in the battery box, which is secured to the trailer floor. |
The gauges consist of a tachometer, oil temp and pressure, as
well as an amp meter. The switchology consists of a master switch,
fuel pump switch, as well as left and
right ignition switches Starter is a push button. Throttle
cable is spring loaded to
the closed position with a pull cable, and mixture is a friction cable, capable of
staying in any position. |
There have been questions about the ignition system, so I've posted
some photos here.
The coils are joined by an MSD coil joiner, "
Coil Selector".
From the joiner, the single coil wire connects to the firewall via a
"Firewall Feed-Thru" also by MSD.
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The Feed-Thru allows the spark to go through the firewall.
On the engine side, a sparkplug lead directs the spark to the
distributor.
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The original intake manifold was cobbled together quickly, from an old
manifold I had.
But as I had more time, I made a new manifold, specifically for the Dragonfly.
But the carb I had
been using was giving me some serious problems.
A rebuild and
a conversion to gravity feed in time for Laughlin 2004; it worked
ok, but we weren't totally delighted.
But we finally got the carb issues solved with the use of the AeroCarb,
and ran the engine at Copperstate 2004.
Although I had sent the carb back to the MFG for all the required and
suggested mods,
I was experiencing the stickiness associated with the
guillotine slide type of carbs when they transition from
idle (low MP,
high vacuum) to higher RPM settings.
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...so we tried a
Revflow and ran it before and during the Laughlin 2005
fly in.
What a HUGE difference! This is by far the best carb we've tried
to date.
Although no further testing has been done since Laughlin 2005,
we'll get all the bugs totally worked out by Copperstate 2005 and we'll
run it there again.
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The procedure for engine start with the old carb:
- Clear the area.
- Master switch on.
- Fuel pump on, wait for audible change in pump tone.
- Fuel pump off.
- Ignition switch on.
- Clear the area.
- Pump throttle once.
- Engage starter.
- Pump throttle once again while cranking, engine should
start.
- Once engine is running, immediately turn the fuel pump
on.
- Allow engine to idle smoothly while oil pressure builds and
temps rise before high RPM runs.
With the new Revflow:
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