1. Field of the Invention
The present invention relates to a system and method for enhancing the performance of internal combustion engines, and, more particularly, the present invention relates to a system and method for preheating engine coolant prior to it being recirculated back through the heat generating components of an internal combustion engine.
2. Description of the Related Art
While the present invention will be discussed herein with respect to snow machines for illustrative purposes, the present invention applies equally to all types engines and should not be limited to only those explicitly discussed herein. The terms snow machine, snow mobile, and sled will be used interchangeably herein.
It has been known that, in certain circumstances, the life span of snow machine engines can be extremely short. In some instances, engines fail within a very short time span of initial use. The cause for this quick failure has been determined to be due to a flaw in the coolant system. For typical snow machines, the cooling system is a loop that starts at the coolant reservoir. The reservoir is connected to a coolant pump by a hose. The pump causes coolant to flow from the reservoir, through the pump, and into the engine where it removes heat in known fashion. The heated coolant is then pumped through coolers or coolers that run the length of the tunnel, which is the portion of the snow machine that the seat and gas tank sits on and which covers the track. The tunnel cooler is located behind the motor under the fuel tank and runs to the back of the snow machine, running up one side and back down the other side of the tunnel, where the coolant is returned to the reservoir.
A typical operating temperature for snow machines is approximate 120-125° F. (Unless otherwise specified, all temperatures cited herein will be understood to be in degrees Fahrenheit.) When the engine is shut off for approximately 10-15 minutes, the hot coolant in the motor causes the engine to heat soak to around 165-185° or more depending on conditions. The motor has a 130° thermostat in the head that closes at 125° and full is open at 135°. Due to the heat soak in the engine, the thermostat is wide open with the engine at this temperature.
At the same time the coolers are filled with coolant. The coolers are exposed to the atmosphere to transfer heat thereto, and the coolant within the coolers is rapidly cooled to approximately 65-85°.
When the sled is restarted within a time frame of approximately 10-15 minutes, the thermostat is open due to the residual engine temperature and the water pump on the front of the motor instantly pumps the 65-85′ coolant from the tunnel into the 165-185° motor. This causes contraction of the cylinder around the heat soaked and expanded pistons, causing scuffing of the pistons and rings, which can shorten the life of the engine. This also causes blow by of exhaust gases by the pistons. This confuses the on board computer, which can cause the computer to shut the sled down. On both carbureted and electronic fuel injection sleds, the sled is over fueled causing burn down and or poor running conditions. The effects are detrimental on both the engine and the electronics.
What is needed is a way to prevent or eliminate this “cold shot” to the engine upon restart.
The invention eliminates the cold shot by installing an inline thermostat between the tunnel coolers and the coolant pump, thereby stopping the cold coolant from ever reaching the heat-soaked motor. This equalizes the cooling system, creating longevity and increasing horsepower and torque. It also eliminates the constant temperature changes, reducing wear and tear on the electrical system and allowing the ECU (on bard computer) and other sensors to run at their designed specifications.
The invention is a flow controller for an engine cooling system including a cooler, a reservoir, a coolant pump, and an engine bypass port. The flow controller includes a housing and a valve. The housing defines a first entrance, a second entrance, and an exit. A main coolant flow path is defined by the first entrance with the exit, and a bypass coolant flow path is defined by the second entrance with the exit. The valve is positioned along the main flow path downstream from the second entrance. The first entrance is adapted to be connected to the cooler, the second entrance is adapted to be connected to the engine bypass port, and the exit is adapted to be connected to the pump. Preferably, these are direct connections without any other components (other than the coolant hoses or conduit) therebetween. The flow controller is positioned between the pump and the cooler, and preferably between the pump and the reservoir. With the valve closed, coolant from the cooler and/or reservoir is prevented from entering the pump.
The valve is a temperature controlled valve. Unless the coolant flowing along the main flow path (that is, coolant entering from the reservoir and cooler) is at a threshold temperature, the valve is closed, blocking the main flow path. Once the threshold level is reached, the valve opens allowing flow along the main flow path. The threshold temperature is chosen to ensure that no cold coolant is pumped into a hot engine. A preferred value for the threshold temperature is approximately 130° F.
The housing may be made of a variety of materials, but should be made of a material that will not act as a heat sink and cause the valve to be in an open position regardless of the coolant temperature along the main flow path. A preferred material for the housing is nylon reinforced fiberglass.
The present invention is described with reference to the accompanying drawings, which illustrate exemplary embodiments and in which like reference characters reference like elements. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
The system of the invention extends the life of snow machine engines and on board electronics by balancing the coolant temperature to thereby control the expansion and contraction of the engine components.
Preferably, the flow controller is provided in two parts, with the first and third orifices 12, 16 being located on one part and the second orifice 14 being located on the second part—see
Preferably, the valve 19 is configured to open when the coolant entering from the reservoir orifice 14 is approximately 130°. If the reservoir coolant is below this temperature, the valve 19 remains closed.
The secondary flow input orifice 16 can be fluidly connected to a source of heated engine coolant, such as the head bypass port that is typically provided on snow machine engines. With the third orifice 16 placed in fluid communication with a source of heated engine coolant, the cooling system loop remains complete even with the thermostat valve 19 closed. The pump is supplied by coolant entering through the third orifice 16, bypassing coolant from the coolant reservoir and tunnel coolers.
Mounting the inline flow controller thermostat valve 19 in the return hose from the tunnel coolers, along with the hot coolant bypass 16, stops the cold coolant from hitting the engine. Installing the hot bypass 16 allows the coolant to continue to circulate until it reaches at least 130°. The valve 19 includes bleeder holes, which allows a small flow of cold coolant from the coolant reservoir and coolers to pass therethrough. This cold coolant will be preheated by the coolant entering from the bypass orifice 16 before being pumped into the engine, so no cold shot occurs. The bleeder holes allow a small flow through the main flow path, allowing the temperature of the coolant in the coolers and reservoir to rise. Eventually, the temperature will be great enough to open the inline thermostat valve 19, allowing coolant from the reservoir orifice 14 to flow through the controller 1 and into the pump. With the thermostat valve 18 fully open, the flow exiting orifice 12 will be mostly from the reservoir and tunnel coolers through orifice 14 due to the greater size of the main flow path than the bypass flow path. Preferably, orifice 14 and its main flow path has a nominal diameter of approximately 1 inch, and orifice 16 and its bypass flow path has a nominal diameter of approximately ⅝ inch. Thus, the main flow path diameter is approximately twice the bypass flow path diameter.
In deep snow conditions and extreme cold, when the coolant is rapidly cooled below the optimal operating condition, the inline valve 19 will close and the bypass will preheat the coolant to the proper temperature. The flow controller 1 thus protects the engine while it is operating as well as when the engine has been shut off for a time period of insufficient length to allow the engine temperature to stabilize.
The flow controller 1 can be installed on newly manufactured engines, or it can be added to existing engines.
Preferably, the flow controller housing is formed of a material that will not act as a heat sink, which may cause the valve 19 to remain in an open position regardless of the temperature of the coolant entering through the reservoir orifice 14. One preferred material for the housing is nylon reinforced fiberglass.
While the preferred embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. Furthermore, while certain advantages of the invention have been described herein, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
This patent application claims the benefit of U.S. Provisional Patent Application No. 61/573,487 filed on Sep. 6, 2011, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61573487 | Sep 2011 | US |