Cylinder Head Porting, Antique and Hi-Performance American Motorcycles

porting for

Shovel 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

With the resurgence of “old school” choppers/bobbers, and the accompanying come back of the Shovelhead, it was inevitable that there would be a demand for increased performance from these engines.  Though the stock shovel ports do not lend themselves to easy gains in flow as do Evolution and Twin Cam heads, there certainly are improvements to be realized.  Despite a poor port design and wildly varying core shift during manufacture, we are able to achieve good flow from these heads.

If you are building an old school bike and still want some power on tap, or if you have had your old Shovel forever (and will never part with it) but want to upgrade the performance, this porting work will fit the ticket.  If it is all about FAST - get a big inch Evo, but if its partly about CLASS - then modify your Shovel!

We offer two stages of porting on stock Shovel castings

• Torque Port:  This porting makes use of the stock valve sizes.  A bigger gain than from bolting on S&S heads

• Power Port:  2.0” intake valve and a larger port diameter for strokers and high revving stock size motors

Currently we offer only one upgrade to S&S Shovelheads, but boy oh boy what an upgrade it is!

• Power Port Plus:  Complete porting package using thin stem 2” intake valves and larger port diameter

Click the link at your left for more information on porting work  for either stock Shovel or S&S Shovel style castings