Deacon, the master, taking a break. Photo by Chris T.
I ran across a master mechanic, in Oahu, Hawaii, at ProStreet, who recently produced the first Choppers Only Show in Wakiki.He explained the differences between the Evolution configuration andthe Shovelhead and how you can alter your Shovel for reliability andbetter performance. I was intrigued, grabbed my camera girl and wentafter the formula.
Note the heavier/thicker Shovel wheel.
First off the flywheels are 4 pounds lighter, saving 8pounds off the lower end. That’s 8 less pounds the engine is forcedto lug around.
“You can go either way with the flywheels,” Deaconsaid, “although it’s easier to just swap them. The new set willalready be correctly clearanced and have a better rod package. Setscan be ordered from S&S in this configuration.”
This shot shows a performance flat top job, a standardShovelhead piston and a Sportster unit. Imagine the spark trying toclimb over that Sportster piston dome.
Next, Evolutions use flat-top pistons for an immediateburn. Shovelheads are equipped with domed pistons and one spark plug.The flame must travel up and over the dome. That can be correctedwith two plugs, but a better way to go is to use the flat-top pistonconfiguration like Evolutions.
“Compression ratio is based on howthe bike will be ridden and how much HP is desired,” Deacon told me.”Use flat top pistons or J&E 30 degree entry pistons with S.T.Dbathtub chamber heads.”
Here’s a shot of the heavier Shovelhead valve on the right andthe lighter stem larger Evolution face for better flow.
The valve train in an Evolution is lighter with smallershaft diameter valves with a larger diameter face for better flow andvolume. “Use Kibblewhite or Manley thin stemmed valves,” Deaconmuttered and went back to work.
Keeper kit from Precision Machine.
A company called Precision Machine offers a conversion kitto use Evo valves in your Shovelhead. “The kit contains the keepersto use Shovel upper collars,” Deacon added. “Also use cast ironvalve guides from Rowe for your specific application.”
Here’s a goddamn stock Shovel valve, lifter and lifter block.An Evo unit will fit right in.
The hydraulic lifters in Shovels are weak and oil poorly.The Bolt pattern for Shovels and Evo lifter blocks are the same, soyou can replace the Shovel lifter blocks with Evo units and a muchlarger automotive type lifter to improve valve train operation.
Here’s the updated Evo valve train configuration. It will boltright in.
Deacon likes S&S oil pumps and doesn’t much care for JIMSreplacement lifters. “Yes, use an S&S oil pump,” Deacon snapped andraised a large torque wrench in my direction. “You will get morevolume for better top end oiling. With more volume you need morescavenging and the S&S pump delivers this as well. Also, Baisleyoffers an overdrive pump gear to provide even more pressure.
A comparison shot of a Shovelhead and Evo lifter.
With the above mods your Shovel won’t work so hard to spinthose heavy flywheels and the valve train will be lighter, moreproficient and flow more fuel, air and exhaust. The pistons will firemore efficiently and won’t be subject to as much heat. The onlyaspect of the Evolution that you might miss will be the flow abilityof the head design.
That’s it, build a Shovel that will last. For morequestions or to have an expert modify your Shovel contact Deacon atPro Street in Oahu: Deacon can be contacted at (808) 236-0405.
c/o The Hogpen
94-084 Leokane St. #B
Waipahu, Hi. 96797
Ride Forever,
–Bandit
