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As pointed out, Honda has incorporated an oil-water cooler into the stock s2000 between the oil filter and the block (picture below), list price $349. They also incorporated an external reservoir into the rear shocks because of limited height and therefore resulting limited gas volume, something many aftermarket shocks ignore.
You realize this is not an oil cooler... this is an emissions device to bring the oil up to temp... it's essentially an oil *WARMER*
Originally Posted by DavidNJ
Here you are misinformed and way off-base. An oil-water heat exchanger is virtually always the preferred solution, whether the heat exchanger is built into a radiator tank or a separate unit. It has two significant advantages: warming the oil when cold and maintaining a constant differential between the water and oil temps.
Note that air/water intercoolers are common for superchargers. Water has about 2x-2.5x the thermal capacity and thermal conductance of oil. The resulting heat exchanger of water to air has at least a 50% higher heat transfer coefficient. This setup adds a compact liquid-to-liquid heat exchanger using an existing efficient water to air heat exchanger rather than introducing a less compact oil-to-air heat exchanger.
Your statement above is right, but you've twisted the facts. Is an oil to water heat exchange the preferred solution over water to air or oil to air? Yes! *IF* (and this is the big point that your entire argument hinges on) *IF* the water you are discharging the heat into is COLD, not HOT. Heat transfer works on temperature differential.... the more temperature differential (delta) between the two fluids the more heat is transferred (it's not linear), and the closer to equilibrium the two mediums are the less heat is transferred. In the instances you listed above, there are fluid pumps and an external air to water heat exchanger... if you left hot water in the heat exchanger, little heat transfer would take place (which is exactly the issue with trying to extract heat from hot oil into hot coolant). Oil to Air has a MASSIVE advantage over Oil to Hot Water.
Originally Posted by DavidNJ
They also incorporated an external reservoir into the rear shocks because of limited height and therefore resulting limited gas volume, something many aftermarket shocks ignore.
We don't... we bent over backwards to create a custom Ohlins DFV long-stroke rear shock kit. Those who care, bother to do things properly. Those who want to make money, sell products that will return money, regardless of performance.
You realize this is not an oil cooler... this is an emissions device to bring the oil up to temp... it's essentially an oil *WARMER*
Ohhh yes! Because it has a thermostat that close the water pass once the oil temp is ok? No it hasn´t. So It is what everibdy konws as oil-water heat interchanger. and works to temp oil up, and to temp oil down, depending of temperture differential, it is exactly the same concept than the JR radiator but smaller.
Originally Posted by SakeBomb Garage
Your statement above is right, but you've twisted the facts. Is an oil to water heat exchange the preferred solution over water to air or oil to air? Yes! *IF* (and this is the big point that your entire argument hinges on) *IF* the water you are discharging the heat into is COLD, not HOT. Heat transfer works on temperature differential.... the more temperature differential (delta) between the two fluids the more heat is transferred (it's not linear), and the closer to equilibrium the two mediums are the less heat is transferred. In the instances you listed above, there are fluid pumps and an external air to water heat exchanger... if you left hot water in the heat exchanger, little heat transfer would take place (which is exactly the issue with trying to extract heat from hot oil into hot coolant). Oil to Air has a MASSIVE advantage over Oil to Hot Water.
That is the good thing about this concept, and this why it does not need a thermostat because it intrechanges heat when needed, if no temp differential, no heat interchange is needed. And this is why an air oil cooler needs a thermostat and this is why the oil takes more time to warm, and this why the oil temp depends of the weather where the air has a huge temp variations, that does not happen with an oil-water heat interchanger.
Ohhh yes! Because it has a thermostat that close the water pass once the oil temp is ok? No it hasn´t. So It is what everibdy konws as oil-water heat interchanger. and works to temp oil up, and to temp oil down, depending of temperture differential, it is exactly the same concept than the JR radiator but smaller.
The factory Honda piece does both quite effectively. I removed it at a track day where I was testing an standard air/oil cooler. The oil took more laps to come up to temp and was nearly 15 deg hotter without it.
You realize this is not an oil cooler... this is an emissions device to bring the oil up to temp... it's essentially an oil *WARMER*
Your statement above is right, but you've twisted the facts. Is an oil to water heat exchange the preferred solution over water to air or oil to air? Yes! *IF* (and this is the big point that your entire argument hinges on) *IF* the water you are discharging the heat into is COLD, not HOT. Heat transfer works on temperature differential.... the more temperature differential (delta) between the two fluids the more heat is transferred (it's not linear), and the closer to equilibrium the two mediums are the less heat is transferred. In the instances you listed above, there are fluid pumps and an external air to water heat exchanger... if you left hot water in the heat exchanger, little heat transfer would take place (which is exactly the issue with trying to extract heat from hot oil into hot coolant). Oil to Air has a MASSIVE advantage over Oil to Hot Water.
We don't... we bent over backwards to create a custom Ohlins DFV long-stroke rear shock kit. Those who care, bother to do things properly. Those who want to make money, sell products that will return money, regardless of performance.
Getting the oil up to temp is important in many forms of racing as well as street use as cracknut indicated. The oil/water heat exchanger helps with that, the oil/air one doesn't. An oil/water heat exchanger and a water/air heat exchanger are both more efficient than an oil/air heat exchanger.
Originally Posted by JRC
Ohhh yes! Because it has a thermostat that close the water pass once the oil temp is ok? No it hasn´t. So It is what everibdy konws as oil-water heat interchanger. and works to temp oil up, and to temp oil down, depending of temperture differential, it is exactly the same concept than the JR radiator but smaller.
That is the good thing about this concept, and this why it does not need a thermostat because it intrechanges heat when needed, if no temp differential, no heat interchange is needed. And this is why an air oil cooler needs a thermostat and this is why the oil takes more time to warm, and this why the oil temp depends of the weather where the air has a huge temp variations, that does not happen with an oil-water heat interchanger.
Originally Posted by cracknut
The factory Honda piece does both quite effectively. I removed it at a track day where I was testing an standard air/oil cooler. The oil took more laps to come up to temp and was nearly 15 deg hotter without it.
Note that drag racers have chillers for engine's coolant, heaters for the engine oil, and intercoolers for the turbo that use dry ice. The oil heaters aren't used anymore as the current racing synthetics have pretty much constant viscosity. They were necessary when straight 40 or straight 50 was common.
Your statement above is right, but you've twisted the facts. Is an oil to water heat exchange the preferred solution over water to air or oil to air? Yes! *IF* (and this is the big point that your entire argument hinges on) *IF* the water you are discharging the heat into is COLD, not HOT. Heat transfer works on temperature differential.... the more temperature differential (delta) between the two fluids the more heat is transferred (it's not linear), and the closer to equilibrium the two mediums are the less heat is transferred. In the instances you listed above, there are fluid pumps and an external air to water heat exchanger... if you left hot water in the heat exchanger, little heat transfer would take place (which is exactly the issue with trying to extract heat from hot oil into hot coolant). Oil to Air has a MASSIVE advantage over Oil to Hot Water.
If I am not mistaken the specific heat capacity of water is approx. 25 times higher than the one of air. And this affects the heat transfer much more than the temperature difference.
Water's specific heat capacity is 4200 Jkg-1K-1 and Air's is 993 Jkg-1K-1 therefore waterhas 4.23 times more specific heat capacity.Water has a density of 1000/m3 and air has a density of 1.275/m3 therefore water would be 784.31 x denser than air.
So, not even close to 25x's.
But there is a lot more to it than heat capacity :
This is because for water to increase in temperature, water molecules must be made to move faster within the water; this requires breaking hydrogen bonds, and the breaking of hydrogen bonds absorbs heat. Heat capacity is the capability of water to absorb heat without undergoing an increase in temperature
Google (and physics education or teachers) are your friend
01-29-2017, 04:12 PM
