John, Dave, Douglas ( --- my son ), and list: The effect we're discussing
here, the utilization of the air flow past the open ends of either individual
pipes from each cylinder, or collecters which team up these runners into a
large diameter pipe ( if the collector is circular --- some are not ), to
gain an extraction effort on the exhaust gases --- is known as the Bernoulli
principle. We've all probably used spray guns on our cars and other
projects, and that spray gun, or your wife's or girlfriend's perfume
atomizer, use this principle to "lift" , or pull, the fluid involved into the
airstream which is rushing past a small orifice at the upper end of the tube
immersed in that fluid.
This principle, it would seem, could be used to good advantage to aid
flow out of the cylinders, thus enhancing the fuel mixture flow INTO the
cylinder, thereby reducing the TIME required to "change" each cylinder. This
results in increased HORSEPOWER, as H.P. is a measurement of work done in a
GIVEN TIME. One H.P. = 550 foot - pounds of work PER SECOND.
We know we need LOTS of H.P. to push our racecar --- be it a "brick" or a
sleek lakester or 'liner --- to really fast speeds. My youngest son Darrell
is a great fan of this theory that WAY TOO MUCH HP IS STILL NOT ENOUGH ! I
often tell him he goes by the " sledgehammer " approach to speed.
I believe that in order to actually realize any useful gain by
"extraction", that individual stacks, mounted at 90 degrees to the airstream
going along the sides of the car MIGHT work the best, but I think that to get
this on pipes of , let's say from 1 3/4" dia or so on a smaller engine, to 3
1/2" or so on a bigger mill --- that the vehicle would have to be traveling
at a speed VERY FAR beyond it's ultimate capability. To reduce the diameter
to obtain a much smaller cross - sectional area at the pipe end, hoping to
better its relationship to the flow going past, would obviously be TOTALLY
Counterproductive, due to the resultant INCREDIBLE BACK PRESSURE created !
These are just my thoughts --- I can't see any useful application of
Bernoulli's law here. Maybe Mayf could dope all this out on his computer ---
I sure can't. Remember, those exhaust gases are already under tremendous
positive pressure to escape --- ever stand 10 feet or so from (JUST an
UNBLOWN smallblock) and feel the " slugs " of air hit your pantslegs from the
old " straight out stacks " ?? Many of us have ---that's LOTS of
pressure, and hard to improve on ! Besides, like Dave Haller likes the
collectors coming out the front fenders on his altered --- "cool !" he says
---well, we ( Doug , Darrell and I ) like the looks of ours - same place -
on the Black Radon altered, and I, myself, don't care if we lose a few
horses in the design! MAYBE we can spare a few -----
Bruce Ferguson Black Radon Engineering Racing Team
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