Outboard motor cooling system with inserts to affect operating temperatures

Abstract

Inserts are disposed in water passages of the engine of an outboard motor in order to inhibit the flow of water, drawn from a body of water, in thermal communication with certain portions of cylinder walls of the engine. Extensions are formed as an integral part of the inserts in order to maintain the proper location of the inserts within the cooling passages.

1 . An outboard motor cooling system, comprising:
 an engine comprising a block portion and a head portion, said block portion having a cylinder disposed to support a piston therein for reciprocation along a generally horizontal path;   a water passage formed within said engine and disposed in thermal communication with said cylinder, said water passage having a first portion extending in a direction toward a crankcase of said engine and a second portion extending in a direction toward said head, said first and second portions being spaced apart horizontally;   a water pump disposed in fluid communication with said water passage and with a body of water in which said outboard motor is operating, said water pump being configured to draw water from said body of water and induce said water to flow through said water passage; and   an insert disposed within said water passage at a location which inhibits said water from flowing in thermal communication with a portion of said cylinder extending away from said head in a horizontal direction.   
   
   
       2 . The cooling system of  claim 1 , wherein:
 said location is within said first portion of said water passage.   
   
   
       3 . The cooling system of  claim 1 , further comprising:
 an extension, formed as an integral portion of said insert and extending in a direction into said second portion of said water passage.   
   
   
       4 . The cooling system of  claim 1 , wherein:
 said insert is made of a water impermeable material.   
   
   
       5 . The cooling system of  claim 1 , wherein:
 said insert is shaped to provide an interference fit with said water passage.   
   
   
       6 . The cooling system of  claim 1 , wherein:
 said insert is configured to have a plurality of ribs formed on at least one of its surfaces.   
   
   
       7 . The cooling system of  claim 1 , wherein:
 said engine comprises two of said cylinders, said water passage is disposed in thermal communication with said two cylinders, said insert being disposed within said water passage at said location which inhibits said water from flowing in thermal communication with said portions of said two cylinders extending away from said head.   
   
   
       8 . The cooling system of  claim 1 , wherein:
 said water is returned to said body of water after passing through said water passage in thermal communication with said cylinder.   
   
   
       9 . An outboard motor cooling system, comprising:
 a four stroke engine comprising a block portion and a head portion, said block portion having a cylinder disposed to support a piston therein for reciprocation along a generally horizontal path;   a water passage formed within said engine and disposed in thermal communication with said cylinder, said water passage having a first portion extending in a direction toward a crankcase of said engine and a second portion extending in a direction toward said head, said first and second portions being spaced apart horizontally;   a water pump disposed in fluid communication with said water passage and with a body of water in which said outboard motor is operating, said water pump being configured to draw water from said body of water and induce said water to flow through said water passage; and   an insert disposed within said water passage at a location which inhibits said water from flowing in thermal communication with a portion of said cylinder extending away from said head, said location being within said first portion of said water passage and spaced apart from said head in a horizontal direction.   
   
   
       10 . The cooling system of  claim 9 , wherein:
 said insert is shaped to provide an interference fit with said water passage.   
   
   
       11 . The cooling system of  claim 10 , further comprising:
 an extension, formed as an integral portion of said insert and extending in a direction into said second portion of said water passage.   
   
   
       12 . The cooling system of  claim 9 , wherein:
 said engine comprises two of said cylinders, said water passage is disposed in thermal communication with said two cylinders, said insert being disposed within said water passage at said location which inhibits said water from flowing in thermal communication with said portions of said two cylinders extending away from said head.   
   
   
       13 . The cooling system of  claim 9 , wherein:
 said insert is made of a water impermeable material.   
   
   
       14 . The cooling system of  claim 9 , wherein:
 said insert is configured to have a plurality of ribs formed on at least one of its surfaces.   
   
   
       15 . The cooling system of  claim 9 , wherein:
 said water is returned to said body of water after passing through said water passage in thermal communication with said cylinder.   
   
   
       16 . An outboard motor cooling system, comprising:
 an engine comprising a block portion and a head portion, said block portion having a cylinder disposed to support a piston therein for reciprocation along a generally horizontal path;   a water passage formed within said engine and disposed in thermal communication with said cylinder, said water passage having a first portion extending in a direction toward a crankcase of said engine and a second portion extending in a direction toward said head, said first and second portions being spaced apart horizontally;   a water pump disposed in fluid communication with said water passage and with a body of water in which said outboard motor is operating, said water pump being configured to draw water from said body of water and induce said water to flow through said water passage, said water being returned to said body of water after passing through said water passage in thermal communication with said cylinder; and   an insert disposed within said water passage at a location which inhibits said water from flowing in thermal communication with a portion of said cylinder extending away from said head in a horizontal direction.   
   
   
       17 . The cooling system of  claim 16 , wherein:
 said engine comprises two of said cylinders, said water passage is disposed in thermal communication with said two cylinders, said insert being disposed within said water passage at said location which inhibits said water from flowing in thermal communication with said portions of said two cylinders extending away from said head.   
   
   
       18 . The cooling system of  claim 17 , wherein:
 said location is within said first portion of said water passage, said insert being shaped to provide an interference fit with said water passage.   
   
   
       19 . The cooling system of  claim 18 , wherein:
 said insert is made of a water impermeable material and is configured to have a plurality of ribs formed on at least one of its surfaces.   
   
   
       20 . The cooling system of  claim 19 , further comprising:
 an extension, formed as an integral portion of said insert and extending in a direction into said second portion of said water passage.