Liquid Cooled Cherokee 180 sails by a Piper Arrow IV
Powered by a Cool Jugs, liquid cooled Lycoming O-360 engine.
When it comes to proving how fast an airplane can go nothing
beats an air-to-air comparison. We suspected that our Cool Jugs
Cherokee 180 was flying quite a bit faster than it did with its
standard aircooled engine but we wanted to be sure. So we set
out to compare our fixed gear, hershey bar winged, liquid cooled
Cherokee 180 against a 1979 Piper PA28RT-200, Arrow IV - a retractable
gear, 200HP airplane with a more efficient semi tapered wing.
What we witnessed surprised even us.
Of course this would all be just 'hangar talk' without proof
so before taking to the air we brought our trusty video camera
along on the Arrow IV so we could record the results of our test.
As you will see - the video camera wasn't operated by a professional
and its a little rough - a testament to the fact that nothing
was rehearsed. Watch the video.
You will notice the somewhat less than perfect formation flying
but in the end you will watch our liquid cooled Cherokee 180 just
walk on by the Piper Arrow IV.
At Liquid Cooled Air Power, we set out almost 8 years ago to
create a liquid cooled aircraft piston engine that could
be used in both new and existing aircraft. We knew that liquid
cooling the engine would bring greater reliability, performance
and fuel economy. We also suspected that existing aircraft would
achieve some performance gains based on the reduction in cooling
drag that is possible with a liquid cooled engine installation
along with some drag reduction due to more streamlined cowling
designs. However, we didn't expect to achieve such a substantial
performance gain on an existing arircraft with so little effort.
The only real difference between the stock Cherokee 180 and our
Cool Jugs conversion is firewall forward. We have not modified
any other part of the airframe as part of the conversion. The
significant modifications are the Cool Jugs liquid cooling conversion,
the re-designed cowling and an MT 3 bladed electric constant speed
propeller. We know from dyno data that the engine in the Cherokee
180 is putting out 185 hp at most. Furthermore, the extra blade
of 3 bladed propeller creates additional propulsion drag when
compared to a 2 bladed propeller. The Piper Arrow IV is a completely
stock airplane with a 2 bladed constant speed propeller. In effect
the Arrow IV has all of the advantages - retractable gear, a semi
tapered wing, 20HP more, a 2 bladed propeller. Yet we still went
past it. The pilot of the Arrow IV could barely believe what he
Here is a look at the Arrow IV from the Cherokee:
While others are just talking about new engines - we are flying
one. We are proving the value and performance of a liquid cooled
engine in flight, in an existing aircraft, using a well known
base engine that is purpose designed for powering aircraft and
that is well supported in the field today!
Aircooled engines are obsolete - they just don't know it yet...