Engine Performance Dyno Runs
Technical information on Stage 2 engines for Harley-Davidson motorcycles.
Basic Stage Two Engine Design
The Stage Two Basic engine represents a more extensive
approach to improve engine performance with bolt-on components and a bolt-in camshaft.
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 30 HP and 20 Ft.Lbs of torque can be seen on some bikes.
The major changes for a Stage Two Basic engine over the Stage One Advanced is the addition
of an Andrews EV-46 camshaft. The original cam bearing was removed and replaced with a
Torrington. The stock Harley-Davidson push rods were used.
Prior testing with the Screamin Eagle 6000 RPM street ignition module had already
produced excellent. No reason was seen to change from the SE ingition module. A maximum of
73.9 HP occured at 5950 RPMs, with maximum torque of 78.1 ft. lbs. at 4100 RPMs.
The HP and torque curves for this engine combination was very smooth, with a broad torque
curve over 70 ft. lbs. starting at 2500 RPMs and extending to 5400 RPMs.
Crankshaft and Flywheel: H-D
Intake Valves: Stock Diameter
Exhaust Valves: Stock Diameter
Valve Springs: H-D
Compression Ratio: 8.5:1
Cam: Andrew EV-46
Carb: Stock Keihin CV with DynoJet recalibration kit installed
Carb Jetting Information: 180 main jet, 45 slow jet installed
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
|73.9 HP @ 5950 RPM
78.1 ft. lbs. Torque @ 4100 RPM
Last updated June 22, 2006
Stephen P. Mullen
P.O.Box 1085, Oldsmar,FL 34677
All rights reserved
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