Kubota Newbie
Active member
Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
Nobody is an idiot, it's just that everybody interchanges two terminologies (back pressure and exhaust velocity) that aren't really interchangeable in terms of discussing engine exhaust flow.
Oil based or latex?
BTW, mufflers generally speaking, are not a "restriction" on the exhaust system for their intended application and within the engines intended operating range. Cut one apart sometime and you'll quickly find that the total opening area within the muffler is greater than the combined open area of the engine valves as it is running. So there really isn't a restriction in terms of open area available for flow. The muffler "muffles" by causing the flow to change direction repeatedly, canceling the sound waves against each other and the internals of the muffler. All this changing direction reduces the "velocity" of the exhaust gas which is where performance gains, or losses, begin to be realized.
Technically speaking though, the "pressure" in the cylinder and exhaust system is higher than the surrounding atmospheric pressure from the moment the exhaust valve opens. That's why it's trying so hard to get out the end of the pipe, it's rushing out to try and fill the space where the lower atmospheric pressure exists. Just like air rushing in to fill a vacuum.
Oil based or latex?
BTW, mufflers generally speaking, are not a "restriction" on the exhaust system for their intended application and within the engines intended operating range. Cut one apart sometime and you'll quickly find that the total opening area within the muffler is greater than the combined open area of the engine valves as it is running. So there really isn't a restriction in terms of open area available for flow. The muffler "muffles" by causing the flow to change direction repeatedly, canceling the sound waves against each other and the internals of the muffler. All this changing direction reduces the "velocity" of the exhaust gas which is where performance gains, or losses, begin to be realized.
Technically speaking though, the "pressure" in the cylinder and exhaust system is higher than the surrounding atmospheric pressure from the moment the exhaust valve opens. That's why it's trying so hard to get out the end of the pipe, it's rushing out to try and fill the space where the lower atmospheric pressure exists. Just like air rushing in to fill a vacuum.
