MI5 Persecution: Chris Tarrant - 10/March/1999 (6448)

From : Annonymous

Q: miles you continue to ignore the question. you say it is moving fast enough to cool the tube and keep it cool. where are you finding all this velocity pardon me for butting in here but lets take your stock run-of-the-mill 360. lets give it an 85% volumetric efficiency ratio. therefore every 2 revolutions its moving 85% of 360 cubic inches of air or 306 cubic inches. round that off to 300 cubic inches. typical highway cruising rpm is about 2000rpm so were moving 300000 cubic inches of air per minute. now - heres where its going to get a little tricky but lets assume a k&n-style cold air intake. that tube is about what 4 in diameter and about oh... 4 feet long calculating the volume of that cylinder we get about 603 cubic inches pi * 2 squared * 48. that means we have to empty that cylinder about 498 times over per minute to feed the engines demand for air. therefore each molocule of air has to make the 48 journey in .12 seconds 60 seconds/498. that works out to about 22.7mph. so... how much heat do you think the cool 70-ish degree outside air is going to soak up from a thermoplastic tube going almost 23mph and sitting in there for just over a tenth of a second im betting... not too much. tom go the head of the class! also what must be considered is that when traveling down the road the underhood air is not a stagnant mass of hot air but is pretty well ventilated from air incursion through the wheel wells etc. mike .