Cylinder Head Porting, Antique and Hi-Performance American Motorcycles

porting for

Twin Cam 

Cylinder Heads

flow figures are based on testing on our SuperFlow SF600 flow bench @ 28” test pressure.  Results may vary slightly due to differences in casting between heads of the same type

As can be seen from the above chart, there is potential for major improvement, both in the stock Twin Cam castings and the Screamin’ Eagle heads.  We have recently streamlined our process and now offer two different types of port job.

  The “Torque Port” is a great upgrade for your stock heads and gives the biggest bang for the buck.  It flows more than enough to support well over 100 rear wheel horsepower and 100 ft lbs of torque on a 95 inch (more on a 103) using your stock head castings.  Likewise the “Torque Port on Screamin’ Eagle 110 heads will support over 130 horsepower (we have seen 128 horse at the rear wheel using a fairly mild cam of only .560 lift;  we have also seen 141 horsepower from the same porting with a slightly hotter cam).

 For those of you seeking even more performance we offer the “Power Port.” Larger intake valves and more intensive porting make this the choice for high revving/ high horsepower motors.

Click the links to your left for more information on these porting jobs for either Screamin’ Eagle or stock Twin Cam castings.