Fuel system having a cooled injector

1. A fuel system for an engine, comprising:

an air box fluidly connected to a combustion chamber defined by a cylinder of the engine by an air intake port formed in a side of the cylinder;

a gaseous fuel injector mounted inside the air box and configured to inject gaseous fuel radially into the combustion chamber through the air intake port;

a primary cooling line configured to circulate a coolant through the engine; and

an auxiliary cooling line positioned inside the air box and fluidly connecting the primary cooling line with the gaseous fuel injector.

2. The fuel system of claim 1 , wherein the air box houses the primary cooling line.

3. The fuel system of claim 2 , wherein the fuel system is configured to direct air through the air intake port of the cylinder.

4. The fuel system of claim 3 , wherein at least a portion of the gaseous fuel injector is mounted at inside the air intake post to inject gaseous fuel with the incoming air.

5. The fuel system of claim 1 , wherein the auxiliary cooling line directs coolant around a valve block of the gaseous fuel injector.

6. The fuel system of claim 1 , wherein the auxiliary cooling line directs coolant through a valve block of the gaseous fuel injector.

7. The fuel system of claim 1 , further including a liquid fuel injector configured to inject liquid fuel into the cylinder.

8. The fuel system of claim 1 , further including a return line fluidly connecting the auxiliary cooling line to the primary cooling line.

9. The fuel system of claim 1 , wherein the coolant is water.

10. The fuel system of claim 1 , wherein the coolant is oil.

11. The fuel system of claim 1 , wherein the coolant is fuel to be injected by the gaseous fuel injector.

12. A method of cooling a fuel injector of an engine comprising:

circulating a coolant via a primary cooling line located in an air box of the engine;

directing the coolant through an auxiliary cooling line to a gaseous fuel injector to cool the gaseous fuel injector; and

returning the coolant to the engine;

wherein the aft box is fluidly connected to a combustion chamber defined by a cylinder of the engine by an air intake port formed in a side of the cylinder, and

wherein the gaseous fuel injector is mounted inside the air box with at least a portion thereof mounted inside the air intake port.

13. The method of claim 12 , further including directing air from the air box of the engine through the air intake port.

14. The method of claim 13 , further including injecting gaseous fuel from the gaseous fuel injector through the air intake port with the incoming air.

15. The method of claim 12 , wherein directing the coolant to a gaseous fuel injector includes directing the coolant around a valve block of the gaseous fuel injector.

16. The method of claim 12 , wherein directing the coolant to a gaseous fuel injector includes directing the coolant through a valve block of the gaseous fuel injector.

17. The method of claim 12 , wherein the coolant is water.

18. The method of claim 12 , wherein the coolant is oil.

19. The method of claim 12 , wherein the coolant is fuel to be injected by the gaseous fuel injector.

20. An engine comprising:

an engine block defining a cylinder;

a piston;

a combustion chamber at least partially defined by the cylinder and the piston;

a plurality of air intake ports defined by the cylinder;

an air box fluidly connected to the combustion chamber by the plurality of intake ports;

a gaseous fuel injector configured to inject gaseous fuel radially through one of the plurality of air intake ports and into a cylinder of the engine;

a primary cooling line configured to circulate a coolant through the engine; and

an auxiliary cooling line mounted inside the air box and fluidly connecting the primary cooling line with the gaseous fuel injector,

wherein the gaseous fuel injector is mounted inside the air box with at least a portion thereof mounted inside the air intake port.