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Don't let the Harley heat monster ruin your riding.
Reduce  Engine Surging
Improve Throttle Response
Reduce Engine Ping


HD 2007/2008 Engines

High Heat on 2007/08 HD engines

HD 2007/08 Performance Recommendations

Cool your exhaust temperature with the Wide Band O2 upgrade for 2007/08 HD

Harley Camshaft Specification Tables

HD Twin Cam Engine Builds
TC 128 HP 95 CID
TC 100HP Street Engine

The basics of Fuel Injection explained

Rammer Performance Air Cleaners
TC Performance Heads 100+HP

Pro Tuning on a Shade Tree Budget


Stage 3 Modifications
Building a 82 horsepower 1340 Evolution engine

Performance and Technical information on Stage 3 modifications to a Harley-Davidson 1340 Evolution motorcycle engine.

Building the ultimate street bike engine
How to get 82HP from your 1340 Evolution engine.

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The camshaft in your bike has been upgraded. If you have made these Stage 2 changes to your bike and are still looking for more power, you may be ready for a Stage 3 engine where modifications can begin to get a little more complicated. Better flowing heads and increased compression ratios are the way that this is usually done.

There are many companies out there that are competing for the dollars that Harley-Davidson owners are willing to spend on their bikes. As an owner, you will be bombarded with a vast array of promises, claims and inaccuracies in an effort to separate you from your money. Reading between the lines on many of the performance claims can be bewildering.

Does the Harley-Davidson world need another bolt together engine modification article? We decided it does, since the results obtained by the engine upgrades listed here provided significantly better results than those documented by the popular magazines aimed at the V-Twin crowd. The Motorcycle Performance Guide staff continues to obtain better results than the "experts" in the press.

How to build your own Stage Three engine

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This Stage Three engine did not involve any internal changes to the engine other than replacing the OEM heads with the Screamin Eagle 1340 EVO heads. All modifications are made by bolt-on changes. Some special tools and training is required to perform these modifications. Unless you are a very good mechanic, it is recommended you find a competent shop to install the heads. For those of you that want to install the heads yourself, Motorcycle Performance Guide recommends you obtain the proper service manual for your bike.

Over the past several years we have installed and tested many manufacturers components. The list of parts used in building the ultimate 'bolt-on parts' engine is the end result of this testing. The best and least expensive of the individual components was selected an tested as a single package. The fact that virtually all the parts used for the project are from Harley-Davidson is a coincidence. There was no plan or idea to use mostly Screamin' Eagle parts for this project.

All the parts used are readily available through your Harley-Davidson Dealer. The components were installed and tested on a 1997 FXD Dyna Super Glide. No special tuning was performed to achieve the results listed. All components were installed according to the manufacturer instructions supplied.

bulletBuilding your Stage 3 engine
Stage 1 improvements must be in place
Stage 2 improvements must be in place
Replace the OEM heads with the new Screamin Eagle Evolution heads
Change Oil and Filter
Install new spark plugs
Road test the bike
Dyno Tune the bike

The results of the Dyno testing are excellent as this bike's performance continues to improve. The test results showed the engine producing 81.7 horsepower @ 5700 RPM and 87.1 ft. lbs. of torque @ 3900 RPM. The long, flat power curve on this engine is ideal for street riding. There was an 18 horsepower increase over the Stage 1 results and an 8 horsepower increase over the Stage 2 engine. The engine is producing 28 horsepower more than a stock bike. Not bad for the relatively investment in time and money required to get these results.

Just how fast is fast enough is a matter of opinion. This 97 FXD was taken to the local drag strip in order to establish what sort of 1/4 mile times could be turned with this bike. The bike proved to be a potent Harley drag race bike by turning times in the 12:40 range with 105 MPH speeds. Considering the rider for this test is relatively inexperienced, it is expected that in the hands of an experienced racer, times in the 12:20 is quite possible.

bulletThe Dyno Run Sheet

The results are due to a well matched set of parts being bolted-on to the engine. Seems that a little of that money the Dealers send back to Milwaukee is going into engine performance research.

The ability to create similar results with other manufacturers parts is a distinct possibility. Motorcycle Performance Guide chose to work with parts that had proven ability to provide increased horsepower and torque. If you use the parts listed in the "Ultimate Street Engine" series of articles, there is little doubt in our minds that your can duplicate our results, provided the engine is in good mechanical shape and properly tuned. Optional parts that have similar specifications to the components used in our engine should provide very similar results. A matched set of engine components, careful assembly and dyno tuning are the keys to building a killer street engine. May your results be a successful as those we have documented.

The Parts List for Bolt On Stage 3 Performance
New parts cost $799.00 plus tax.
Maintenance parts cost about $80 plus tax.
Dyno Tuning costs estimated at $200.00 plus tax.

New Heads

Screamin Eagle 1340 EVO heads
$799 list price (silver) complete with valves and springs

Other Items

Top End gasket set from James Gasket
Harley-Davidson Double Platinum Spark Plugs or H-D Gold Spark Plugs
Harley-Davidson Oil Filter
Mobil 1 15-50w Synthetic Motor Oil (3 quarts)

The Horsepower Gallery provides an extensive list of bikes , the power they produced and the major engine components.


Table of Contents
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Nightrider COPYRIGHT

Ask us a Question

Modification, Installation, Maintenance and Tuning Index  will help you find most of the information you want on one page.

How to get Professional Tuning Results at home
Testing the Innovate Motorsport LM-1 portable air fuel meter

Profession Tuning on a Shade Tree Budget

Veypor VR2 Data Logger and Instrument Panel
Video Installation and Demo
Purchase VR2

Engine Performance
How to Build a
TC96 2007 Engines
TC88 70HP Stage1  
TC95 128HP Stage 3
TC95 100HP Street
TC96 2007 Stage 1/2
EVO 64 HP Stage 1
EVO 74 HP Stage 2
EVO 82 HP Stage 3
EVO 95 HP Stage 3
883 to 1200 Upgrade
Shovelhead Modifications

New EFI for EVO and TC

Performance Gallery
Horsepower Gallery
Evolution 80
Twin Cam 88/95
Evolution Unlimited
Sportster Unlimited
Drag Strip Gallery
Land Speed Racing Gallery
CV Carburetor
Modifying the CV carb
Tuning a CV carb
Selecting a cam
Install a TC 88/95 cam
Install a Big Twin cam
Install Sportster cams

Camshaft Specifications
Twin Cam

Exhaust Systems
EVO Exhaust Testing
TC Exhaust Testing
Khrome Werks AR100 test
Making Drag Pipes Work

Shop Manual
Carburetor Troubleshooting
Finding Manifold Leaks
Cylinder Heads
Pistons and Cylinders
Belt Drive
Shop Manual Appendix
$20 Bike Lift
Plug Wires
Spark Plugs
Engine Tuning
Nitrous Oxide
Motor Oil
Stutter Box
General Information
WEB Links
Buy Books and Manuals
Performance Calculations
Estimate Horsepower
Estimate 1/4 Mile Time
Estimate Top Speed

Engine Displacement
Exhaust Length
Gear Ratios
Air Density

The Nightrider Diaries
The ramblings of a genius a, a madman and something in between.

Where is Sifton Cams?

Autocom Active-7 tested

Harley-Davidson EFI
-EFI basics explained
-EFI modifications explained

183 HP, 2 carbs, 2680cc

Copyright 1997-2006  Stephen Mullen, Oldsmar, FL -+-