Registered: June 2004 Location: Potomac Posts: 732
This chart shows the linear relationship between the heat rejection (load) of the coolant and the required (calculated) coolant flow in the engine water jacket. It is determined for 3 different temp gradients of the engine inlet and outlet coolant temp. This engine example is from a 500+ horsepower supercharged gas engine assumed to have heat rejection up to maximum power (8,000 btu/min). Why do we care? If you cant keep engine temps under control at speed under load, you may have: 1) insufficient water flow, 2) undersized radiator, or 3) insufficient air flow through the radiator that needs to be addressed. This engine will require coolant flow in the lower part of the curve in street applications (low heat rejection), but for racing/track use this engine will require coolant flow rates towards the top of each curve. For older V8's pre-emissions, the common design target is to keep the radiator Inlet @ 190 F and outlet @ 180F or an average core temp of 185F at steady state conditions or the upper curve shown. Modern engines may use a little higher 195F-185F or rad core avg temp of 190F.
· Date: Thu March 19, 2009 · Views: 312 · Filesize: 33.1kb · Dimensions: 417 x 500 ·
