exhuast ...suction charging...
exhuast ...suction charging...
(OP)
I have been thinking about this for a while now, and was wondering if the, ..air flow .. under the car, can be used to make the exhuast gasses travel faster,so that ..more..air can be sucked out off the cylinders, to help the ..scavenging,of the combustion chambers
the air would have to be funneled into a ..venturi.. shape , then put in to the exhaust pipe,to speed the air up,relative to the vehicles speed,
any help woould be much appreaciated
Marcus Aurailius
the air would have to be funneled into a ..venturi.. shape , then put in to the exhaust pipe,to speed the air up,relative to the vehicles speed,
any help woould be much appreaciated
Marcus Aurailius





RE: exhuast ...suction charging...
It can only work if the fluid doing the pumping is flowing faster than the fluid being pumped.
Exhaust gas normally travels a lot faster than a cars road speed.
I strongly suspect that collecting air over a very large area and concentrating it down to a small area to increase speed will consume more power that the scavenging produces.
Tuned length exhaust headers, tuned length variable inlet runners, high compression, pent roof 4 valve head design and variable cam timing all combine to give good scavenging, so there is little room for furter improvment.
Regards
Pat
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RE: exhuast ...suction charging...
this is where a 2 valve engine is ..off cam.. and was thinking,that if the gas could be ..pulled.. out sooner, then the engine would come on cam earlier,.
tuned lenght manifolds,ex/in, can only work best at a certain r,p,m.
what i am thinking is to try and give the engine a help before it comes on cam,.
has any one got any figures as to what speed the ex gasses are traveling at,
in a 2.6 engine ,at various r,p,m./load throttle openings,.
if the speed of air is ..then greater.. than the ex gas speed,then one will have a suction scavenging effect!!
Marcus
RE: exhuast ...suction charging...
RE: exhuast ...suction charging...
Exhaust gas velocity can easily be many times the speed of the vehicle, excepting a supersonic jet car, perhaps. Only one of them that I know of.
Rod
RE: exhuast ...suction charging...
RE: exhuast ...suction charging...
RE: exhuast ...suction charging...
I've always assumed this was why so many racing bikes have such high and centrally located exhaust outlets, i.e. so exhaust gas can slightly raise the pressure seen in what would otherwise be the area of lowest pressure (probably still would be...).
RE: exhuast ...suction charging...
I have been trying to find articles relating to this form of suction for a while now,.
But all of the ones i seem to find ,all seem to use some form of ..machanical means.., But none that does it the way i am thinking,.
If any one can point the way to any articles on sucking out ex gasses, I will be pleased,.
The idea is to try and get exhaust gas out, using a venturi style/effect ,caused by car speed /air speed ,to feed into the exhaust,about 3 ft before the outlet of the exhaust,thus ..sucking.. the exhaust gasses out
I am not really interested in top end power, but think that this idea could make the engine pull better at low revs,.
At low revs , small to medium throttle openings,the exhaust gas that comes out of the tail pipe , does not seem to be going that fast,.
This is bourne out by the fact that one can feel the pulses on one,s hand,.and do not seem to have v much speed with them,. {it is a lot faster at the exhaust valve end though],
So if these gasses are slowish, then a venturi effect,with higher air flow , should be able to ..speed them up thus extracting them faster !!!
High lift/long duration cams ,loose power low down,/gain higher up, so I am trying to create the best of both worlds
any help is good help
Marcus
Marcus
RE: exhuast ...suction charging...
RE: exhuast ...suction charging...
rmw
RE: exhuast ...suction charging...
Aero Commanders, older Cessna 310's use it.
RE: exhuast ...suction charging...
RE: exhuast ...suction charging...
but will try it out first by just putting it on the end of the pipe with an adaptor pipe,
can only try, nothing to loose, may be some thing to gain,
will be doing this in a few weeks if i get the time, but will tell if it any good
thanks every one for the intrest
Marcus
RE: exhuast ...suction charging...
They work as you describe above, using air movement under car.
RE: exhuast ...suction charging...
i am half way there now, i got a ..flat box.., 2, ft wide, 2, inch deep, radiusd edges, tapering back to a 2,5in pipe outlet.
this is my ..air scoop.. which will then be put on to the wnd of the exhaust to try it out
if it is any good, then it will be piped into the exhuast further forward
can only try, but thanks for the info,
i think i will finnish it soon, and will let you all no of ..what it did???/
Marcus
RE: exhuast ...suction charging...
Here is a decent article with some science behind it.
http:
RE: exhuast ...suction charging...
Regards
Pat
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