schiker
Well-Known Member
Ok, I think I know more than just the fundamentals of how an engine and a diesel works but let me eat a little humble pie and ask a few questions. I am going to put it here cause I am a 6.5er and it relates to a naturally aspirated IDI engine I am working with.
Bare with me...(I am going to generalize some numbers).
Given an engine has a heat rejection rating at an output will the heat rejection be less at lesser load with the same "fuel" position?
Say a 50 hp naturally aspirated engine is rated for 40 hp continuous load at WOT being 100% loaded. And its rated at 40,000 BTU's/hr heat rejection at this 100% load at this 40 hp.
And its a simple idi mechanical injected engine. So WOT or any throttle position is a set fuel rate of injection. And you set a specific throttle position on an unloaded engine. Say 2600-2700 or very near this governed and rated rpm above. Will the engine require the same 40,000 btu/hr radiator capacity without load or a lesser load?
Or since its really just pumping air at no load will heat rejection be much less say 5,000 btu/hr again at no load.
Again set engine RPM to near WOT the above rated HP output of engine via "throttle position" with no load on engine...
Then if you load a 10 hp load to crank will it require say 15-20,000 btu/hr of cooling.
Load it to 20 hp it will require 20-25,000 btu/hr cooling.
Load it to 30 hp it will require 25-35,000 btu/hr cooling.
Load it to 40 hp it will require the 40,000 btu/hr cooling.
I think that is correct and why a turbo requires fuel and load to build boost. It takes fuel and load to make heat.
OR does it being a diesel engine the fuel rate is set and if you set "fuel pedal" stationary it injects the same amount of fuel per injection event and thus requires cooling according to fuel position. ie if you set WOT or very near its 40 hp worth of fuel being injected and thus 40 hp worth of fuel requries 40,000 btu/hr of heat rejection regardless of load?
Bare with me...(I am going to generalize some numbers).
Given an engine has a heat rejection rating at an output will the heat rejection be less at lesser load with the same "fuel" position?
Say a 50 hp naturally aspirated engine is rated for 40 hp continuous load at WOT being 100% loaded. And its rated at 40,000 BTU's/hr heat rejection at this 100% load at this 40 hp.
And its a simple idi mechanical injected engine. So WOT or any throttle position is a set fuel rate of injection. And you set a specific throttle position on an unloaded engine. Say 2600-2700 or very near this governed and rated rpm above. Will the engine require the same 40,000 btu/hr radiator capacity without load or a lesser load?
Or since its really just pumping air at no load will heat rejection be much less say 5,000 btu/hr again at no load.
Again set engine RPM to near WOT the above rated HP output of engine via "throttle position" with no load on engine...
Then if you load a 10 hp load to crank will it require say 15-20,000 btu/hr of cooling.
Load it to 20 hp it will require 20-25,000 btu/hr cooling.
Load it to 30 hp it will require 25-35,000 btu/hr cooling.
Load it to 40 hp it will require the 40,000 btu/hr cooling.
I think that is correct and why a turbo requires fuel and load to build boost. It takes fuel and load to make heat.
OR does it being a diesel engine the fuel rate is set and if you set "fuel pedal" stationary it injects the same amount of fuel per injection event and thus requires cooling according to fuel position. ie if you set WOT or very near its 40 hp worth of fuel being injected and thus 40 hp worth of fuel requries 40,000 btu/hr of heat rejection regardless of load?
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