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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


Building the Perfect Street Engine

The Sprocket Twins at Nightrider get hundreds of requests for engine configurations. Riders want the simplest engine to build, the highest power than can get, an engine to beat their friends, an engine to go racing with. In short, every rider wants the ideal engine. They want big power increases and instant throttle response. They describe thinly discuised race engine sitting in a street bike. What many riders don't want to discuss or hear are the issues associated with these "over the edge" engines such as:.
-Exceptionally loud exhaust tone (do you really want 120 dB drone in your ears on your FLH when riding down the interstate?)
-A strong tendency to overheat when exposed to parade duty (called cruising around town)
-High detonation potential when running on pump fuel (can you really find race fuel every 200 miles?)
-High maintenance usually requiring decarboning the cylinder heads and pistons on a frequent basis.
-Reduced Reliability (do you really expect an engine that has huge power and ridden very hard to last as long as a stock engine?)
And these are just a portion of the issues you have to face with these "gonzo" engines. Unfortunately, few riders think about this until their dream engine turns into a nightmare 9 months down the road.

After spending a lot of time thinking about what most riders really want versus what they think they want, I decided to come up with my own requirements for a strong engine upgrade package for Twin Cams. It had to meet the following requirements:

bulletAn engine that can be used in heavy FLH's and Road Kings, as well as in the lighter Dyna's and Softail's.
bulletAn engine that will run on pump fuel without having to worry about detonation.
bullet An engine that requires a minimum of parts and doesn't break the bank.
bulletAn engine that has a horsepower figure high enough to get some respect when bench racing.
bulletAn engine that will pull strong from idle and propel the bike to any legal or illegal speed chosen within some reasonable limits.
bulletAn engine that would smoke the other V-twins between stoplights or at the drag strip.
bulletAn engine that would be easy to ride and live with when riding in town.
bulletAn engine that woud have near stock reliabililty.

That would be a good start on our "universal twin cam". While there probably isn't the perfect street engine for your Twin Cam engine powered bike, this comes as close as I have seen to meeting that definition. You'll notice that I never mentioned a specific horsepower figure in our "perfect engine" needs. That's because it is too easy to take a single HP or Torque number and take it out of context. A good street engine has a broad torque curve that gets a bike moving quickly and keeps the acceleration going. A good average power number is more important than the maximum number.

If you went to most shops and gave them this list of "wants" for your updated engine, they would probably tell you that it just isn't possible to build this engine. In most circumstances, I'd have to agree with these shops. Then I saw something that complete changed my opinion on what could be built.

Most riders have been conditioned to believe that for good power, you had to raise the compression ratio to 10.5:1. While most of the lighter Dyna's and Softail's could almost get away with this compression riding around on the street, the heavier Road King's and FLH's tend to have severe detonation issues. While the EFI knock sensors could stop the detonation issue, they also resulted in much lower power than possible with the higher compression. I had never been a big proponent of high compression engines for heavy bikes, especially when I knew that once compression ratio's exceeded 9.5:1 the extra power gained for every point of compression gained was very small. But a high percentage of the HD performance industry insisted on going with these high compression engines in heavy, air cooled bikes. The engineering and physics involved in this never made sense to me.

Enter Wes Brown at CycleRama. Wes' shop in West Central Florida has been building world class engines for all type of bikes for many years. I'm sure Wes got tired of riders asking for big power engines in heavy bikes, then having to "back off the tuning" to handle the way most riders lug their engines around town. While sitting in Wes' shop one day and discussing strong street engines he mentioned a very conservative 100/100+ engine he had recently put together. Knowing that CycleRama always puts together strong engines, I expected to see a nice power curve in the 2800-5500 RPM range. I was completely blown away when he showed me the dyno sheet on this table-top smooth power curve at starting at 2400 RPMs to over 5000 RPM. This same engine made over 100HP, all from a TC95 with a 9.5:1 compression ratio.

As you can see for yourself, this engine begins making power right off idle and is still pulling at 6000 RPMs. While this isn't going to win you any dyno shootouts, do not underestimate the ability to move your bike down the road at some very illegal speeds. This engine is a "roll on" king. Whatever gear you choose, at any RPM this engine is going to pull like a freight train when you twist the throttle around. With its lower compression, it isn't going to have much of a detonation issue. It is actually going to make a bike run much faster than the horsepower numbers would have you believe. In short, very close to an ideal street engine for any TC powered bike.

Component Bike in Dyno Sheet
Possible Alternatives Similar
Carburetor Build
Displacement 95 CID OEM 88CID  
Cylinder Heads CycleRama CNC Ported Free Flowing, professionally ported heads  
Pistons CycleRama big bore Flat top pistons  
Compression Ratio 9.5:1 Less than 10:1  
Camshaft CycleRama Short Duration, Medium Lift
230-240 with .520-.560" lift
Exhaust System SuperTrapp Slip-ons Khrome Werks  Slip-ons
Any good performance exhaust system 2-2 or 2-1
Throttle Body CycleRama modified throttle body SE 50mm Throttle Body Mikuni HSR-42
Mikuni HSR-45
S&S Super E
S&S Super G
Other EFI PowerCommander SE Race Tuner  
Ignition   SE Race Tuner SE Ignition Module
Crane, DynaTek, S&S Ignition Module

While I am showing some alternative engine components, this is for convenience only. The only way to ensure you get the same power results would be to have CycleRama actually build the bike. You should be able to get similar results by order all major components from them. If you want to use other components other than those listed, you can expect different results.

If you want to build an engine like this, you can contact Wes Brown at CycleRama. His phone number is 727.546.0889. I think you will be very happy with an engine like this.

As a note to those riders who want to save some money, this engine combination can be done without going to the 95CID big bore kit. It is estimated that the TC88 version of this engine would make 2-3HP and 3-4 less power, but with the same broad, flat power curve.


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 -+-