Basic Stage one Engine Design
The Stage One Basic engine represents a simple
approach to improve engine performance with bolt-on componentst. Most people can perform
these modifications themselves. Modifications over stock engine are underlined in the list
below. The estimated cost for these modifications ranges from $700 to $1000. The
performance return for these changes can be large for the dollars spent. Increases up to
10 HP and 10 Ft.Lbs of torque can be seen on some bikes.
A maximum of 63.8 HP occured at 5350 RPMs, with
maximum torque of 72.5 ft. lbs. at 3650 RPMs. The HP and torque curves for this engine
combination was very smooth, with a broad torque curve over 60 ft. lbs. starting at uder
2300 RPMs and extending to 5500 RPMs.
Year: 1997
Model: EVO
Bore: Stock
Stroke: Stock
Displacement: 1340cc
Cases: H-D
Assembly: H-D
Crankshaft and Flywheel: H-D
Heads: H-D
Intake Valves: Stock Diameter
Exhaust Valves: Stock Diameter
Valve Springs: H-D
Porting: None
Compression Ratio: 8.5:1
Pistons: H-D
Cam: H-D
Pushrods: H-D
Carb: Stock Keihin CV with DynoJet recalibration kit installed
Carb Jetting Information: 180 main jet, 45 slow jet installed
Manifold: Stock
Air Cleaner: Screamin Eagle K&N
Ignition: Screamin Eagle 6000 RPM street module
Ignition Timing: 32° BTDC
Coil: Screamin Eagle Dual Fire
Plug Wires: Magnecor 8.8mm
Pipes: Stock headers with HD Slip-on Baloney cuts
Dyno Tuning Facilities: CycleRama, Pinellas
Park, FL. (813) 546-0889
