HKS 700E Comparison 582
Green Sky Adventures, Inc.    of North Central Florida
  Toll free 888 887-5625         Cell 352 318-5625    or Email  mail@greenskyadventures.com
Engines
Instruments
Propellers
Micro Mong
Zippy Sport
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?
  1. 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.
  2. 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
  3. 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.
  4. 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
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