im interested if anyone would like to explore how much waste heat is available in an exhaust stream, i have calculated this a few times, but im interested to see others take on it, i based it of of the 1/3 work + 1/3 waste radiator heat +1/3 waste exhaust heat.
i have taken header pipe temps on a 460 efi in our ford, i got 700 deg f right at the header flange
Stock Horsepower is 245@4,000rpm.Torque is 400 lb.-ft.@2,400rpm.Compression ratio is 8.5:1.Some '96&'97 EFI460s had 8.8:1.
my guess is 500 cfm needed for this mild 460 based on this calculator and my experience so far driving with the quadrajet, it is tuned about what a 350 would have for jets and needles. thought that was interesting, runs pretty well now but im sure some tweaking is still necessary.
Carb CFM Calculator
does anyone have experience with heat exchangers? im trying to find out a good way to find the needed surface area for transferring the heat to the intake stream from an exhaust stream? it has to go through a metal pipe, alloy unknown possibly stainless, thickness to be decided. im using a set of headers and another 460 efi (for dirt cheap) to bolt and test fit the "system" while its being fabricated, that way its a perfect fit on the 88 460 efi i have in the truck. im going to weld the heat exchanger onto the headers to effectively do several things: heat air and fuel after atomization from the quadrajet carb, then make the vapors rise a distance to minimize the possibility of unvaporized fuel making it to the intake of the engine. any atomized fuel will fall to the hot bottom of the intake pipe and be vaporized before continuing through the system. i would like to find a nice number for the surface area needed to transfer the energy available in the exhaust to the intake stream. im basically trying to build a scaled up version of marcello's small engine units to test the ability of pouring filtered flammable waste into my fuel tank. i decided to do another rough sketch and ill be posting more of these
ill post my math on using the specific heats on various hydrocarbons along with latent heat of evaporation and the combined energy needed to heat the intake stream and vaporize oils and gasoline, the bottom line is that according to my numbers the energy is available, and there is more energy in the exhaust than what is needed to do what im asking.
a few additional pics:
[IMG]
[/IMG]
[IMG]
[/IMG]