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Aluminium Radiators &
Engineering Pty Ltd |
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GLOSSARY :
Pertaining to this Site
Ambient -- The atmosphere outside of and effecting the cooling medium. Has an effect on all facets of cooling, the higher the ambient temperature, the harder to cool to the same level. BTU -- British thermal unit. Measurement unit of temperature. Cavitation -- Eddying of water off the edges of water pump impellor blades, generating aerated bubbles in the water which can turn to steam and worsen hot spots. Much more detrimental in turbo engines or ported heads. Also promotes corrosion in all engine cooling systems. Core -- Centre part of radiator/intercooler/oil cooler etc, that consists of tubes running between the two header plates carrying the hot medium, & fins joined to these tubes to dissipate the heat to the ambient air flow. Corrosion -- Chemical or electrical removal of material from a metal, main problem for us is the interior walls of the water jackets. Remember, not only can it cause the very expensive replacement of blocks, heads, housings etc., but the deposits have to go somewhere, and usually that's into the radiator tubes to block them. A double needless expense! Coolant -- Usually misnamed inhibitor. A true coolant may have very little corrosion inhibitors in it, but will raise the boiling point, carry heat away from hot spots and exponentially lower the water temperature, ie:- the hotter the engine runs the better the coolant keeps the temperature down, might lower it 2 deg. at 90 deg. but 6 deg at 120 deg. Chemical Current -- A small electrical current that is generated from mixing chemicals in the cooling system. Can be detected for up to a day, after running a cleaner through the system, flushing and then adding inhibiter. Detonation -- Aaaaaaaahhhhhhhhh !!! The Achilles heel of the force fed internal combustion engine. When the flame front travel in the combustion chamber destabilizes and causes preignition - the fuel mix explodes to early in the upward stroke of the piston. Fixes are different piston dome &/or combustion chamber shape, higher octane fuel, retard timing, enrichen mixture, lower compression, lower boost, water injection and/or the only device which noticeably increases power, fit an intercooler! Dimple wall -- A process that presses small square depressions into the wall of a water tube to break up the capillary tension water has. Gives approximately 6 % more cooling. Dissipation -- The transferral of heat from the hot medium through the tube wall into the fin and then taken away by the cooling medium. Efficiency -- The percentage cooling offered by the cooling unit. The equation is hot medium - cooled medium X 100 Note that this is for Intercoolers, Radiators, oil coolers etc., not Turbos. hot medium - ambient Engine -- at college I was taught an engine is an internal combustion power plant & a motor an electrical power plant Fins -- A strip of aluminium that is folded to "zig zag" between the two flat sides of the tubes. A fin in a 500mm long tube, can be 2400 mm long! It is these joints that gives an aluminium core it's advantage over copper/brass, as solder is a very poor conductor of heat compared to the all aluminium fused joint. FPI. or fpi. -- Fins per inch. The number of fins attached to the wall of the tube. The more fpi., the better the heat dissipation up until the fpi ratio exceeds the core thickness slowing down the ambient air passage through the core. Header Plate -- A plate with holes punched (rarely machined) in it to allow the tube (part of core) to protrude through. Clearance of the slot is very important for proper tube fit & sealing at manufacture, which then affects longetivity. Joins the hot medium transporting (part of core) tube to the tank. Intake Charge -- The air that has been sucked/forced on it's way between the air filter & the combustion chamber. Intercooler -- A heat exchanger used to cool the hot pressurized intake charge of a turbocharged/ supercharged engine. The cooling gives a denser charge with more oxygen for kw. gain and also less chance of detonation. Motor -- At college I was taught a motor is an electric power source & an engine is an internal combustion power source Oxidation -- The breaking down of the alloy external surface. Turns to a powdered insulating coating that for maximum cooling, needs to be cleaned off every few years, acidic cleaning works best. A much slower process than the corrosion of copper fins, at least 400% slower! Pipe -- Solid, usually round tube to transport a cooling medium. Polished -- Bloody hard messy work that we can't charge high enough hourly rate to make it worthwhile. Looks Good! Radiator -- A heat exchanger used to cool the engines coolant. Needs air flow to dissipate the heat out of the radiators core. Coolant heat is unwanted by product of the engines power. Step Back -- Or overhang, where the header plate sits over one side of the core more than the other, usually used to gain more volume. Stray Current -- A small electrical current in the cooling system, usually from a bad earth on the vehicle. Measured with a special tester or analogue multi meter. Maximum allowable in aluminium system is 0.05 volt. The silent killer of aluminium radiators! Supercharger -- A mechanically (usually belt/s) driven compressor with rotors/vanes/turbines that force large amounts of air into the combustion chamber. Usually will not heat the intake charge as much as a turbocharger for the same pressure boost. Uses allot more engine torque than a turbocharger. Tank -- Contains the hot medium between the inlet/outlet pipe and the header plate. Usually a closed rounded rectangle shape. Also a vessel to hold liquids. Thermostat -- Controls the travel of fluid in relation to it's temperature. The opening of the valve/flap/piston is controlled by a wax pellet, so replace after 4 or 5 years. A cold engine will wear out allot quicker than a hot engine. Throttle Body -- Housing containing the throttle butterfly/s which control the amount of air entering the combustion chamber. Usually has a sensor to tell the computer the % the throttle is open. Torque -- Imperial measurement of the twisting force generated to lift a set weight a given distance. Used in formula with revs to give horsepower readings. Gives an engine "grunt". Turbocharging a n/a engine can more than double the torque output, interestingly, mostly less than halving the life expectancy. TPI or tpi. -- Tubes per inch. The number of tubes across the width of the header plate. The more tpi. the larger volume of water that can be transported through the core still in contact with the cooler tube wall. Tube -- The solid rounded rectangular section to transport the heated medium (water, oil and intake charge) past the cooling medium -air or water. Needs a flat side wall to give a sufficient surface area of contact with the fin fold. Turbocharger -- A compressor with two turbines on each end of a shaft. The driving turbine is rotated by the exhaust gasses, twisting the other turbine, which in turn sucks large volumes of air into the housing, compressing & heating the air in the process and forcing it into the combustion chamber. Can supply higher boost than supercharging. Negligible engine power drain. |
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Pty Ltd (ARE Cooling) |
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