Misfires cause it to read lean because it lets unburnt fuel into the exhaust. Unburnt fuel being a liquid means theres only oxygen for the sensor to respond to.

 

It is false period. Exhaust is like any other gas it needs a certain restriction to flow properly. Too large of a flow area will slow the gas down and not allow the gas to flow efficiently because of a lack of back pressure. No back pressure will cause a dramatic loss in low end and mid range power.

With exhaust systems you have to balance the power level of the engine with the most efficient exhaust gas velocity to make the most power.

 

My all mechanical blow thru carbed car was blowing out the spark on the stock ignition system at around 12 psi. Car would pop and sputter and generally not pull. Stock gap was like .040" I moved it all the way down to .016" and the problem vanished. Started moving it back out to .018" then .020" then when I went over .025" it started having issues again. Stock HEI with stock coil etc. and parts store wires.

High cylinder pressure 100% will cause missfire. My car was lean if anything during my problem so it wasn't too much fuel. Also Copper Core Autolites are easier to fire than "Platinum" plugs or other hi-mileage low maint. type plugs. I got rid of the AC delco because they fouled too easy from constantly starting and moving the car in & out of the garage all the time without driving. Once Autolites were put in. No more fouling.


Someone else posted that many times a car will idle halfway decent then act up going up a hill or under a load....It is the same principal. Higher heat and cylinder pressure reaches a point where the spark just cant jump the gap or it finds a place of less resistance and jumps that gap....

I have seen it too many times 100% in personal experience.

 

correct.
at some stage, the exhaust pressure MUST be larger than intake manifold, to creat the turbine shaft speed...end of story...
its called spool up...

after the intake manifold goes into positive pressure ( from vacume) , yes then the exhaust can be , LESS pressure than intake boost

 

It don't need restriction to flow. Less friction is more flow.
Area is another subject and here you are right that the gas need a certain speed, but not for the flow.
When the valve open the pressure difference between the cylinder and exhaust pipe is high, but at the end of the exhaust stroke the pressure is almost equal. If you then have no pipe, to short pipe or to large diameter the atmossferic preshure is working against the savaging of the cylindrer.
If you are using a pipe where the speed is coorect and the lengt is coorect you can get a pressure lower then atmosferic pressure at the end of the exhaust stroke halping to savange the cylinder.

could you then tell me how gas turbines work? Presshure don't drive turbos, heat is.

 

[ could you then tell me how gas turbines work? Presshure don't drive turbos, heat is.
[/quote]

gas turbines work alittle differently
the turbine requires temp drop across the turbine, pressure drop across the turbine , and gas flow.
depending on fuel types used, the density of gas plays a bit part too

edit:
just to add a few more points.. alot of your comments are really good, and correct, but but others lack a bit of physics's and theory...
if temp was the only thing that drives a turbine, why does gas motors , drive a turbine the same as methanol , and diesel ??
gas egt's are way,way hotter than methanol...and different to some diesels too
in a high compression methanol engine, the egt can be less than 900deg F , and the turbo still works ?? but its 300+ deg F colder than gas ??
also think about this one.... if you had a 1inch hose , @ 50 psi blowing on a shop fan... the fan spins
now change that 50 psi hose FROM air , to water , and still use same 1 inch hose...
the medium , or fluid density has changed, but now has more force on the fan...

this why, methanol fuel engines can spool up slightly better, due to the extra density in the gas exiting...

hope this helps understand

 

Helps me understand? Guess 2 years calculating turbos, gas turbines and steam turbines at school was a waste.
If the pressure dropp so will the temperature. kj/kg/k x kg/s x k=kj/s=Nm/s=W
If pressure was needed to get turbos to work then two stroke B&W and Sulzer Diesels would fail to work.

 

It really does not matter what you did in school. That goes for any schooling. It only teaches you so much.

It appears you are only in this thread to argue. If you want to continue this discussion start your own thread.

 

oh well, i tried...
maybe im doing shit wrong?

 

First problem...Is anyone who went to school thinks they know more than a person who has personal life experience....Just drives me nuts. School is like a computer, bad info in Bad info out.

As my Dad always says, Those that CAN do and those that CANT teach.

Raw heat alone isn't going to turn a turbo...Airflow is the number #1 reason it turns...Heat just makes it more efficient. The heat effect is felt while climbing a hill or sensing a load. But the airflow has to be there with it.

The piping diameter before a turbo has a large impact on performance. ISNT that airflow related more than heat?

Why are turbos rated by airflow instead of response to heat? Over educated idiots shouldn't argue with real car guys....

 

man it's more like "stAIn1979" you're a shitty spot on good thread, open your own for discussion or post something helpfull for the question at hand.

 

"Stain1979" should have gone to school for something more usefull in his/her everyday life....Like spelling. I saw horrible spelling errors in the posts I read. Once the spelling is figured out then maybe they could take the time to get some hands on experience with turbo's.


And if a student of a school doesnt read or spell well doesn't that throw off their ability to learn CORRECTLY? (Giving school some benefit of doubt)


LOL, I was married for 4 years....I did that pretty badly....Now I am single again. Did 4 years make me a pro at marriage? NAH.

 

ROFL