I'm looking for information pertaining to the design of an engine cooling system in a heavy duty truck -- one that's used for long haul shipping. I've found some resources that provide details on the main components -- radiator, fan, pump, reservoir, thermostat, etc. -- but, I've found little in terms of the specific design features -- pipe diameter(s), flow rates, etc. Some design information on the cooling system in a popular truck model, such as a Volo VNL series with a D13, D13TC or Cummins X15 engine would be appreciated.

My ultimate goal is to try to construct the cooling system, removed from the engine. Specifically, I'd like to know the exact parts that go into the cooling system of one of these trucks. I know the pump is driven from the timing belt of the engine, I'm assuming this means the rpm of the pump is equal to the rpm of the crankshaft, and therefore varies depending on the vehicle demand. I understand the mechanism for the fan might be slightly more complicated, as its necessity is only imperative for when the vehicle is stationary. I'd also appreciate some recommended resources for learning about some of these design components. I'd really appreciate some guidance and any useful information. Please let me know fi you have any questions.


Lucas W.


1 Answer 1


Well, first the rpm of the water pump is not equal to the rpm of the engine crank, the pulley diameter ratio drives the water pump faster.

As for design parameters, start with the amount of heat that has to be removed to keep the engine within its temperature limits at max power as that is the worst condition. Remember to include things like if the turbo has extra cooling.

Once that point is defined, you can start to size the radiator needed, considering capacities, flow rates and issues such as loosing ram cooling while engine is at max power ie it is going slow pulling hard and relying on the cooling fan(s) only.

Then the control such as bypass and thermostat needs consideration as the amount of cooling needs reducing if the engine is only gently working so it is not overcooled.

For fans, there are many choices such as electrically driven with full electronic control to provide a speed and airflow matched to the cooling required.

Lots of things that I have not mentioned but it’s a start for you to expand on.


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