Dispelling Some Myths About Water Cooling

It's Time to Take Full Advantage of Advancements
Made in Water Cooled Engine Technologies!

About the Benefits
  • Overview
  • Getting rid of the heat
  • Heat - the top end killer
  • More power per cubic inch
  • Better performance and fuel economy
  • Radiator technology - past and present
  • Shock cooling - Problem solved!
  • The secret to achieving longer TBOs
  • Flying faster on the same power - reducing cooling drag
  • Side benefits - Safer cabin heat
  • Dispelling the Myths

  • How long are we going to hold on to obsolete concerns of the past?

    Over the last 30 years we have learned a tremendous amount about how to design lightweight and reliable cooling systems. Through racing experience we have found out how to properly cool high performance engines. Today we use high precision manufacturing technologies to cast and cut the parts that make up our engine components minimizing manufacturing flaws and making better use of the base materials.

    Back in the 1950's and even through the 1970's brass/copper radiators where the norm. These radiators were both thermally inefficient and were prone to cracking and leaking under vibration. Brass/copper radiators are now a thing of the past. Aluminum radiators provide much better thermal efficiency and are much more capable of withstanding the vibrational environment of an aircraft installation. Where a brass/copper radiator would barely be able to hold 20 psi of pressure - today's aluminum radiators can withstand pressures upwards of 50 to 90 psi without failure.

    Myth - Air-cooled engines are very reliable

    Do you really think that air cooled engines are that reliable? Think again. There are far more catastrophic failures of air cooled engines than you might care to admit.

    As pilots, we are indoctrinated to believe that we are less likely to suffer an engine failure than any other reason why we might have to deal with an unscheduled landing. While statistically speaking that may be true - statistics can also provide a false sense of security. I'll venture a bet that you either (a) had one of the following failures or (b) know someone that had one of the following failures or (c) have a friend or acquaintance that knows someone that had one of the following failures. If you said yes to a, b or c above then statistically speaking there is a 1 in 6 chance it could happen to you!

    Consider the more common failures that are reported:

    • Separation of the exhaust valve from the stem.
    • Exhaust seat falling out of the head.
    • Cylinder separation from the crankcase.
    • Piston and/or piston pin failure.
    • Broken rings - severe loss of compression failure.
    • Some other top-end related engine failure.

    These failures are almost all heat related. The tremendous heat stress that the exhaust valve and seat are exposed to. The soft metal that air-cooled heads are made of can barely retain the exhaust valve seat at high temperatures. The detonation that most likely contributes to the separation of cylinders from the crankcase. All of these failures are massively catastrophic and have resulted in the loss of life on many occasions.

    Our company president with about 1000 hours flying time suffered a catastrophic oil pump failure in July 1996 while flying behind an O-360 Lycoming engine. Luckily he was able to land without incident. Statistics would have you believe that such a failure would be virtually impossible for someone to encounter with as little as a 1000 hours of flying time. The reality is that the oil pump failure suffered by our company's president along with the other catastrophic failures listed above occur far more often than the statistics would suggest.

    The bottom line. We can hold on to obsolete concerns of the past - or we can move forward - improving our engine's reliability and even reducing the chances of catastrophic failure due to the high operating temperatures of our air cooled engines.

    "What if it springs a leak?"

    The fact is, if the coolant system is properly maintained there is a much lower possibility of a coolant system leak or failure than an oil system leak or failure. Consider that the oil system in an aircraft engine must be capable of handling what is essentially a corrosive and highly viscous fluid at high pressure. The oil pump in an engine is subject to extreme stress when the engine is started cold. Why? Because it must pump a very viscous fluid at high pressure. The forces and horsepower required are very high. Oil pump failures are far from uncommon. Likewise oil coolers must be designed to withstand the higher pressures of the oil system and of course lets not forget the hoses and fittings between the engine and the oil cooler.

    Are you thinking about your car's cooling system? Soft rubber hoses and hose clamps that tend to loosen up? Fan belts that break at the most inopportune times? Well don't even compare your car's cooling system to what we have designed for our Cool Jugs' cooling system. Our goal has been to design a system that is more reliable than the engine's oil system.

    Our company president - who is also the Chief Engineer and Test Pilot for the water cooled conversion project provided the basis for the design. He said, "I want to feel confident flying a water cooled single engine aircraft over the Mojave desert on a cold dark night, under a high overcast without a star in the sky"

    To meet that requirement we use only well established aviation grade design techniques and hardware. For example, the coolant hose kit for the Cool Jugs conversion utilizes AN fittings, and steel reinforced synthetic compound hoses with a 500psi burst rating that are fully aviation certified TSO C53a. That's a burst rating that is over 25 times the operating pressure of the cooling system!

    Our coolant pump is the essence of simplicity and reliability - designed to last at least 10,000 hours it is gear driven directly by the accessory drive with one moving part that does not come in contact with anything other than the coolant. A long life ceramic water seal prevents any leaks. As for servicability - the pump can be overhauled with a pair of snap ring pliers and a light press.

    Our coolant manifold is constructed of 6160-T6 aluminum components and is designed to not suffer any fatigue as the result of thermal expansion and torque flex that occurs during engine operation.

    Finally - we worked with mother nature! Yes, we designed our cooling system to have a natural convective flow so that even in the highly unlikely event of a cooling pump failure the system would still be able to keep the engine temperature under control. The natural convective circulation is so effective that it will continue to cool the engine while it is running at power levels up to 30% without the coolant pump operating! While 30% may not sustain level flight in many aircraft it will considerably extend the glide performance and will allow the engine to be operated at maximum power in short bursts as necessary to execute a safe landing.
    Cooling System Analyzer Even with all of the effort we put into designing a leak proof and reliable cooling system we went one step further - we designed and built a sophisticated cooling system analyzer that will provide the earliest possible warning of a cooling system issue before it becomes a critical problem. Our cooling system analyzer provides a complete picture of the condition of the cooling system and can provide a warning when as little as 8 fl.oz. of coolant is lost from a 2.5 gallon system - long before there would be any urgency. It uses technology and methods that are so unique that we were awarded US Patent #7,069,883 on July 4th, 2006.

    Ease of Maintenance

    Every aspect of the Cool Jugs conversion has been designed to allow ease of engine maintenance. We have made sure that the system is entirely 'bolt on' with all components easily accessible for inspection and maintenance. We have eliminated virtually all gaskets and replaced them with 'O' rings that provide a more reliable seal and are less prone to leakage.

    The only recurring maintenance that we require is that the system thermostat and the coolant be changed at every 3rd annual inspection or 1000 hours of operation, whichever occurs first. Over time we will likely extend the change interval as we gather more long term data.

    Put you mind at ease...
    Be assured by these facts!

    • Highest Quality Aviation Components
    • Minimal Changes to Base Engine
    • No Changes to Any Internal Parts
    • Modular Design Utilizing a Minimal Number of Unique Parts
    • High Performance Gear Driven Coolant Pump
    • Precision Made Parts Using the Latest Casting & CNC Technologies
    • Strong, Reliable & Light Weight Components


    Liquid Cooled Air Power © 2001 Liquid Cooled Air Power. All Rights Reserved.
    1413 Prospect Ave., Hermosa Beach, CA 90254
    Proudly MADE in the U.S.A.
    Proudly MADE in the U.S.A.