Bethania Garage Inc. & Hard Dog Fabrication Bethania Garage Inc.  Logo
The New RevTech® 100" 4"x4"



The engineers and technicians at RevTech® went back to the drawing board to create our next generation 100" engine. We studied the latest technology, combined that with expertise gained on the first RevTech® 100 project, and got down to the task at hand. The goal was simple; create the best all-around engine for the American V-Twin market!


  • Cast from 356-T6 aluminum with wall thickness optimized for maximum strength
  • Advanced one-piece casting and machining techniques allow for near perfect case half alignment
  • Blind case bolts for cleaner appearance
  • Smooth crankcase deck to cylinder base profile for cleaner appearance
  • 7/16" cylinder studs proven in drag racing applications


  • Connecting rods and flywheels forged from 4340 chrome moly steel - the strongest material available for these applications
  • Larger straight 11/2" pressed in crank pin using RevTech's proprietary extreme-duty military-grade steel

Oiling System

  • The most advanced oil scavenging system produced yet for air-cooled V-twin applications resulting in better reliability and increased horsepower
  • 3:1 ratio oil pump drive gears and high volume oil pump enable significantly increased lubrication and cooling
  • Piston cooling oil jets for better heat dissipation


  • 4"-bore with 4"-stroke for optimum power and reliability
  • More fin area for increased cooling
  • Machined fin edges for better appearance
  • Forged Wossner slipper-skirt pistons with moly coat


  • New RevTech ® roller rockers
  • john reed design ™ sculpted two-piece rocker boxes
  • More fin area for increased cooling
  • Machined fin edges for better appearance


  • Mikuni HSR 42
  • Intake manifold matched to heads for ideal flow efficiency
  • Low profile air cleaner design for high performance while providing improved rider comfort


  • Self contained solid-state ignition


  • Andrews EV72 .560" lift cam for good performance and easy starting
  • EPA cam - Andrews 322B4 .525" lift
RevTech Engine    RevTech Engine    RevTech Engine

Fortunately the RevTech® design staff did not have to start from scratch.

We began with a solid foundation, the fire breathing RevTech® 110 power plant, and refined it further to produce a motor for most everyone. By shortening the stroke to 4", excellent balance with less vibration was achieved. A positive side-effect of the shorter stroke was reduced piston speed which increases reliability due to lowered stresses.

The 4" pistons pushed on these 4" strokes are a special story in themselves. RevTech® worked with Wossner to design unique moly-coated forged pistons specifically for our engines. If you're not familiar with Wossner, here's a bit of background, they make pistons for a little company called Porsche, among others!

Next we redesigned the heads. The bigger bore of the new 100 allowed the use of larger valves, so the ports were also redesigned for better flow. Smaller combustion chambers provide greater squish area for better turbulence and efficiency. In addition, roller rockers are employed for better valve train reliability.

Many of the fine features of the RevTech® 110 were retained due to their proven success. Pressed-together flywheels and our industry-first monoblock crankcases are still used for excellent reliability. Blind case bolts, machined fin edges, and john reed design™ rocker boxes follow the RevTech® tradition of making it work good, and look good. And loads of horsepower and torque for all types of riding come standard.

So did we reach our goal of the best all-around engine on the market? We think we did and believe you'll agree. Remember, there are millions of American V-Twin motorcycles on the road today; why not make yours perform like one-in-a-million?

The New RevTech 100inch 4inch x 4inch
Click to Enlarge Image


Updated May 5, 2005 10:27 PM