Get XiED(tm)! Performance Parts

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


Selecting a Performance Camshaft for you Harley-Davidson

Selecting the correct camshaft for you bike can be confusing and frustrating. The more popular cams available may not be the right cam for the way you ride or the type of bike you have. A cam that is installed in a show bike featured by the 'biker' magazines may not be part of a proven engine performance combination. When it comes to improving your bike's performance by installing a cam, you should deal with a reputable performance shop and a proven record on improving power.
hd_cam_lobes00.jpg (13151 bytes)
A stock cam is on the left, a 268 degree duration cam with a .600" lift is on the right.

In order to get the best performance, the camshaft must be matched to all the other engine components. The combination of carburetor, intake manifold, head design, flow characteristics, valve size, bore, stroke, compression ratio, ignition system, exhaust system and the way you are going to ride the bike all have an impact upon the best cam to select. If head work or pistons are not in your budget, then your choices are limited to bolt-in cams. Even limiting your cam selection to a bolt-in cam provides you with a wide choice of options. Most bolt-in camshafts are intended for use with bikes and engines that have few modifications. The minimum requirements for a bolt-in cam is usually a re-jetted carburetor, a high-flow air cleaner and a less restrictive exhaust system.

Make sure you match your riding style or needs to the the horse power and torque characteristics of the cam. The biggest mistake made in cam selection is getting to much cam for the bike, the way it is ridden or the components on the bike. A good set of pipes, some minor upgrades to the CV carburetor, a good ignition system and the right cam can produce around 75 HP when properly tuned.

Bolt-in Cam Selector

In order to simplify your selection of a camshaft, the Motorcycle Performance Guide created a list of the most bolt-in camshafts for Harley-Davidsons. Find the type of bike, the riding style and your favorite cam manufacturer. A list of recommended camshafts is given.

If you ride a heavy bike like a Road King or always ride two up, you should place more emphasis on having the engine produce good low end torque. If you have a light bike like an FXR or Dyna, and you want a lot of top end power, a mid-range power cam can be used. If you usually ride your bike in town, choose a camshaft for low end torque. If you have your choice between horsepower or torque for engine characteristics, the best decision is to go for the torque cam.

As a general rule, cams with 220-235 degrees of duration tend to produce good low end torque. Cams with 235-250 degrees of duration tend to work best in the mid-ranges and cams over 260 degrees work best for top end power. Camshaft overlap duration less than 30 degrees tends to produce good low end power. Lobe Separation Angles (LSA) of 100-103 degrees tend to produce power at the low end.

Cams with valve lifts .500 inches and under, with a duration under 250 degrees are generally considered bolt-in. Cams over .500 inches lift and 250 degrees duration require increased compression and head work to work best.

Don't think you are going to take your stock bike and turn it into a 100 HP monster by adding a cam, replacing the carburetor and putting on straight pipes. Getting an 80 inch Big Twin engine to produce 100 horsepower at the rear wheel is difficult, time consuming and quite expensive. You are much better off bolting in a Crane Fireball 310, an Andrews EV-27 or a V-Thunder EVL-3010 in your street bike than trying to find a long duration cam because you have been told 'bigger' cams makes more horsepower. A well designed and tuned engine combination, using a mild bolt-in cam is quite capable of embarrassing most other Harley's between stoplights. 100 horsepower is not very useful if the engine does not make power until 6000 RPM. Harley-Davidson Big Twin engines were not designed to take that kind of abuse. An engine with 70 HP at 4800 RPM and 85 foot pounds of torque at 3200 RPM can be a real thrill compared to a stock EVO motors.


Table of Contents
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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 -+-