Crossing Over
Rotax 582 UL vs
HKS700-E
Is it a black and white decision?
To be fair, this comparison is between the Rotax 582 as installed on
the Green Sky Adventures, Inc., Zippy Sport and an HKS 700E which replaced
it. NOTE 5/05 We also have replaced the 582 on our Kitfox. If any
performance was lost it is minimal and without question, we would rather
give up a little power all of the time than all of power some of the time.
Prices are current as of May 01, 2005
For Current Itemized Pricing, clickHERE
|
QTY
|
Total
|
| Rotax 582UL with Type C MESK (starter) with Exhaust |
1
|
$6,323.00
|
| OIL TANK 881 460 |
1
|
$105.59
|
| Radiator 995 697 |
1
|
$349.55
|
| Expansion Tank 180 922 315 |
1
|
$112.66
|
| STARTER SWITCH |
1
|
$8.55
|
| THROTTLE CABLE |
1
|
**$88.00
|
| CHOKE CABLE |
1
|
**$88.00
|
| K&N AIR FILTER 825 723 |
1
|
*$46.00
|
| High Altitude Compensation Kit |
1
|
$215.95
|
|
TOTAL |
$7,337.30 |
**The jury is still out on these cables. Lower cost might
be useable on the 582, (We actually make cables) but these were strongly
recommended for use with our HKS installation. The HKS list at right, is
directly from our purchase order for the replacement engine.
The Green Sky HAC
automatic mixture compensating carburetors are used on our 582 installation.
Not included on the 582 side are small installation items
like Radiator hoses, fittings, and clamps. |
|
QTY.
|
Total
|
| HKS 700E ENGINE (W/ STD. EQUIP.) |
1
|
6,435.00
|
| EXHAUST SYS. (TYPE 1) |
1
|
475.20
|
| OIL TANK |
1
|
389.95
|
| OIL COOLER -16 ROW |
1
|
133.75
|
| OIL HOSE 5/8"
/ FT. |
9
|
60.75
|
| FIRE SLEEVE
/ FT. |
4
|
26.20
|
| STRGT 5/8 FITTING |
3
|
21.78
|
| 45 DEG. 5/8 FITTING |
3
|
55.44
|
| 90 DEG. 5/8 FITTING |
2
|
36.96
|
| STARTER SWITCH |
1
|
6.45
|
| THROTTLE CABLE |
1
|
88.00
|
| CHOKE CABLE |
1
|
88.00
|
| REMOTE ELEC. ACC. CONNECTOR KIT |
1
|
28.00
|
|
TOTAL
|
7,845.48
|
K&N Airfilters are standard with the HKS.
The Bing Constant Velocity Carburetors are about 50%
mixture compensating to approximately 10,000 feet. The Green Sky Adventures,
Inc. HACman
mixture control has been tested on the HKS 700E from sea level to over
14,000 feet and is now an available option for HKS as well as the Rotax
912 series.
|
Comparing the Power
On the surface, it appears we're giving up about five HP making this change.
On our particular application, we actually expect, if there is a perceptible
change in aircraft performance, it will be on the positive side.
Why?
-
The Speed range of our aircraft (40 to 130 mph) is such that extra prop
loading is required in static run / takeoff mode to prevent an excessively
light load in flight. The torque curves of the subject engines are enormously
different, with the HKS maintaining torque as load is increased .
It's power is linear from around 4,000 rpm on up and the curve is comparatively
flat. Our 582 torque falls off very rapidly below 6,000. The substantial
prop load we use brings takeoff rpm down to a point where the two power
curves cross. With additional load, the HKS becomes the more potent powerhouse.
-
Starting out, our 582 is slightly under it's potential because of exhaust
configuration we have chosen. Slight changes in the 582 stock exhaust
have dramatic effect on peak power output. On one test series performed
in 2001 we observed a 250 rpm difference by temporarily changing mufflers.
Such reduced power output is not uncommon. Some of the most popular aircraft
to ever use Rotax 582's have chosen exhaust configurations which reduce
peak power
-
Our conclusion? On faster (relatively) aircraft, such as the Green Sky
Adventures, Inc. Zippy Sport, or even the Micro Mong, a performance difference
between HKS 700E and the Rotax 582 UL is negligible. On slower ULs
or PPCs, the 582 will definitely produce more static thrust and consequently
better performance, probably up to about 60 mph. However, prop diameter
is the limiting factor on many of these. On one test (summer 2004)
we found the HKS 700E would match the static thrust of a 582 2.62:1 with
60 inch 3 bld prop once the HKS was fitted with a 64 inch.
-
To see some of our actual results check out our Prop
Tests page.
Weighing the Options
As equipped, our 582 weighs approximately 108 lb. that total does not
include weights of
-
Oil Tank
-
Oil (5 pint)
-
Coolant, (.75 gal)
-
Coolant Lines,
|
3 lb est
4.375
6 lb
4.4 lb |
| Total |
125.775 |
|
The HKS 700E has a baic weight of 108 lb
Required accessories
-
Exhaust System
-
Oil Cooler and Tank
-
Oil
|
7 lb
6 lb
5.25 lb |
| Total |
126.25 |
|
Do you have time to view some more Cowl-Off
Zippy Images?
In
July 2001, a BD-5 builder spent the day with us using our Zippy Sport as
an engine test bed
How about some pilot's eye images?
Here
are a few shots from a Pilot's point of view taken in NE Ohio December
2001
|