Choosing Cams for Your Harley

Think about the kind of riding you want to do. 

Do you want high-end performance or low-end torque? (You can’t have both.) 

Do you want smooth running and good fuel economy, or an all-out street racer? What is your trade-off between maximum power and a machine you can ride every day, under all conditions.

When you know what you want from your engine, call FLO Headworks and we'll recommend the cams that will work best with your riding style. At the same time, we'll probably recommend our valve spring kit to get the most from your new cams.

Camshaft selection

We asked "The Master", a world famous cam designer, and his answer was, “Whatever works!” or for short, WEW, his patented one-liner. This sounds like a throwaway remark, but underneath there is a lot of wisdom.

There are many factors to consider when choosing cams, and all of them were presented at The Master’s three-day “crammed cam school,” which I attended. There was enough material to cover three weeks!

But the main thing I learned is that "The Master" really knows his cams.

Every cam manufacturer uses computers to match a cam’s profile with the variables of Harley engine design: head flow characteristics, intake and exhaust porting, ignition systems, gearing, displacement, and so on.

And every manufacturer knows the jargon: valve lift, valve timing, duration degrees, overlap, lobe centers, cam base circle 

diameter, cam lift, rocker arm ratio, calve train weight, valve springs pressure, lifter type, roller diameter, hydraulic lifter leakdown rate, hydraulic intensity, major intensity, minor intensity, ramp acceleration, opening ramp type and velocity, closing ramp type and velocity, jerk, and smoothing.

The question is, how will you, the customer, know how to translate all this double-talk and computer output into the right cam for your needs?

The answer is, you won’t. Instead, concentrate on the kind of riding you want to do. Do you want high-end performance or low-end torque? (You can’t have both.) Do you want smooth running and good fuel economy, or an all-out street racer? What is your trade-off between maximum power and a machine you can ride every day, under all conditions.

When you know what you want from your engine, go to your trusted tuner and tell him. Then instruct him to choose the cam manufacturer that knows Harley engines best, and select the model of cams they make that meet your needs.

From 25 years of hands-on experience tuning and porting Harleys, the Crrane cams I sell are specially designed for use with EPA formulated pump gasoline in California, and other states where air pollution requirements are stringent.

Our cams are designed to make real-world horsepower across a broad power band. And they’re compatible with all Screamin’ Eagle high performance parts available for the Twin Cam 88 and 95 cubic inch engines.

If you’re a Twin Cam owner, be sure to check out our new cam kit, especially for this model. It makes a big improvement in that model’s performance.

For more information call the FLO Headworks Customer Service Hotline at 805-481-6300 or e-mail Perry and get a quick reply.

Big Twin cam

Twin Cam 88 cams

Scroll down for prices.

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Valve Spring Kits

When your Harley makes its power in the orange band, 
you're in "fun to ride" territory.

If so, there are a couple of things you should be aware of when comparing the specs. They come down to the “fun to ride” factor.

In my 25 years of experience working with Harleys, I’ve found the most power available from a street Harley running unleaded gas has worked out to about “one per.” What I mean by “one per” is one horsepower and one foot pound of torque per cubic inch of engine displacement.

When you think about it, that’s pretty good. Especially when that power is made without sacrificing low-end performance and engine life expectancy.

If your Harley engine is tuned right, you end up with a bike that’s both fast and “streetable”—in other words, fun to ride!

But that bike won’t necessarily put out the highest HP and torque numbers.

Simply put, you can’t get performance at both ends of the power spectrum. Low end power, low end torque—that’s what your Harley engine was designed to produce. Why? Because that’s the kind of power that counts in real-world riding—pulling away from stop lights, hauling a passenger, passing a car at 60 MPH in top gear.

Take away that torque and you destroy your Hog’s “fun to ride” factor. But that's what you have to do to get those "high end" numbers.

Maximum horsepower ratings sell tuning and aftermarket stuff. So, for many years companies specializing in high-performance products built engines specifically for the Dyno, tuned for maximum HP and little else, just to brag about higher HP numbers.

Examples of HP-increasing tricks that are misleading or make a bike no fun to ride:

• Using cam timing that is not acceptable for pump gas or street use

• Installing high-compression pistons that require 104-octane racing gasoline

• "Calibrating" the Dyno unit to “compensate” for “weather” or “altitude” to produce artificially high horsepower readouts

Your Harley’s gotta run on pump gas, and you want it to have some grunt when you’re pulling away from the lights. So don’t be mislead by the advertisements you read in the magazines. Most high performance companies place those ads to get your money, not for their credibility.

Our philosophy at FLO Headworks it to improve the characteristics that are inherently designed into the H-D engine: fantastic torque and lots of real-world power.

Starting at 2000 rpm on the Dyno curve, our Super Port Flow can give you more real-world horsepower and foot pounds of torque per cubic inch of engine displacement than any other high-performance modification. The focus is on the potential improvement on the lower RPM range where the Harley-Davidson engine was designed to perform.

To quote the owner of our first TC88 R&D project bike, “I can pull the front wheel off the ground at 70 mph in third gear!” Now that’s “Fun to Ride!”

For tuning advice about your Harley-Davidson, call the FLO Headworks customer service hotline, 805-481-6300, or e-mail Perry at [email protected].

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