Stihlverado
Addicted to ArboristSite
According to Jennings header length should be 6-8 times the diameter of the exhaust port at the piston, which is 1.25 x .625:
The port has semi circles at each end with a square in between, so calculated port diameter is the area of a circle with .625 D plus the area of a .625 square.
- The radius of the circle is half of .625 or .3125
- The area of a circle = pi r squared or 3.14 x (.3125x.3125)=.306
- The area of a square = L x W or .625 x .625 = .391
- Total area = .306+.391 or .697
So 6 x .697=4.182" and 8 x .697=5.576"
The pipe's header is approx. 5.25", so it's in the ball park.
How do you figure the diameter and legth of the expansion chamber in conjunction with overall length of the pipe?