TECH: S&S 107″ Cam & Cylinder Kit (Intro)

Our opening shot shows our 2012  Heritage Softail up on Kenny’s lift with the exhaust and top end removed. The gas tank is lifted, and the gearcase section is emptied, except for the oil pump. The pinion shaft runout has also been checked and is below the required 0.003" maximum

Our opening shot shows our 2012
Heritage Softail up on Kenny’s lift with the exhaust and top end removed. The gas tank is lifted, and the gearcase section is emptied, except for the oil pump. The pinion shaft runout has also been checked and is below the required 0.003″ maximum

Our Heritage gained 28 hp and 27 ft-lbs. of torque!

Captions and photos by Chris Maida

Harleys are built to cover some serious mileage. But even the most babied engine is going to need a top end rebuild at some point, although readers of this magazine probably don’t fall into that category. When it comes to the world of Harley-Davidson, anything you want to do has a bunch of different options. So when our high-mileage 2012 TC 103 Heritage Softail started hinting at a new top end, we examined a few of the options. The first, of course, is to rebuild it back to stock specs. Option B is to increase the engine’s displacement and throw in a hotter set of cams. Okay, so our only real options were how big and how hot.

Since the still-young Heritage sees lots of time out on the road, reliability and manners are just as important as power output. For that reason, we turned to the legendary S&S Cycle in Viola, Wisconsin, for a 107″ cylinder kit (#910-0479/$929.95) and its gear-driven HP103GE Easy Start camshafts (#330-0354/$824.95). The wrinkle black, 11-fin cylinder kit fits 2007 and later Big Twins. (No worries Twin-Cooled model owners! S&S has a kit for you, too.) The 3.937″-bore cylinders are the largest size that can fit in stock, unmodified engine cases. That means no machining is necessary, and you can achieve the maximum bore size with minimal effort. The S&S cylinders are also the same height as stock, which, again, makes this an easy install. The centrifugal-cast, gray iron liner and the included 4.937″, 4-3/8″ stroke CP pistons provide excellent wear and noise characteristics and performance. The fin area is increased for better cooling performance over stock cylinders. The cylinders are also available in a silver powdercoated finish, which also matches stock H-D engine finishes. The kit includes gaskets and piston rings, wristpins, and wristpin clips.

With the Heritage Softail’s new displacement, a set of performance cams is necessary to get the most out of the Beta motor. The HP103GE Easy Start camshaft is what S&S calls a “horsepower cam.” However, different intake and exhaust systems can turn the engine into more of a torque monster with a bit less top end. These are actually bolt-in cams, so no modifying of the cam compartment is necessary, a recurring theme with this S&S project. Since the heads and rocker boxes were off the bike when we installed the cams, there was no need to even order a set of pushrods; the stock ones slid right back into place! Of course, besides their high-performance profile, these are gear-driven cams. This means no more chain tensioners (great news for this high-mileage rider), but it also means a longer lifespan for the parts, and a more secure connection inside the engine’s bottom end.

For a tuner, we went with TechnoResearch’s Harley-Davidson (Delphi) 2 (#TR200053-M01-U/$638) tuner. We’ve worked with the TR quite a bit on a handful of different bikes, and it delivers flawless tuning every time. The USB port key allows for multiple reflashes on a single motor­cycle. Our choice for this build is a TechnoResearch DirectLink Flash Tuner. This module allows you to alter the fuel table, spark advance table, and other calibration table values. You can also get real-time fuel table and spark table cell tracing. The DirectLink (Flash-Tuner) communicates directly to the stock EFI module, so there’s no wiring changes or additional modules to install.

As reliable and easy to install as the S&S Cycle cylinder and cam kits are, they provide some majorly impressive numbers on the dyno. The 103″ Softail’s baseline runs yielded 68.9 hp and 87.6 ft-lbs. of torque. After tuning, the Twin Cam puts out 97 hp and 114.9 ft-lbs. of torque! That’s a 40 percent increase in horsepower and a 31 percent increase in torque. What’s really cool is that the same S&S kits also work on 96″ Twin Cams, delivering the same final output numbers. So if you’ve got a 96-incher, you can expect those percentages to be even higher, which makes your dollar-to-power ratio even higher as well!

When it comes to high-performance Harleys in the New York area, Rosa’s Cycle is the place to go. Andrew Rosa lent his skill and expertise to our S&S-equipped Heritage Softail, and the power numbers speak for themselves. Follow along as he takes us step by step in the accompanying photos and captions to see exactly how the experts do it. AIM



Rosa’s Cycle Shop

S&S Cycle Inc.

TechnoResearch Inc.

Like what you see? The full article with all 25 steps, dyno chart, Tips & Tricks, and tools needed, is in American Iron Magazine issue # 324, NOW ON NEWSSTANDS! To order a back issue of this or any other issue of American Iron Magazine, visit
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Retro Tech – Installing A Morris Magneto on a Shovelhead

An Easy-to-Install, Easy-to-Start, All-In-One Ignition System

By Chris MaidaRetroTech-MagnetoMention using a magneto ignition and many riders envision a hard-to-start 1960s Ironhead Sportster, the culprit behind many a bad right knee. Being a veteran of many long kickstarting sessions myself (I had a bike shop before the advent of the Evo), I know exactly what they’re thinking. The same image came to mind for me when Kip Watkins said he wanted a Morris Magneto on the boardtrack Shovel he was building for me. But the Morris magneto of the 21st century is not the same as the ones I remembered from four decades ago! These ignitions start easy!

Remember my Shovel build? We started that project a long time ago, in a galaxy far, far away. Like many of my builds, it got sidetracked due to my travel and production schedules. Thankfully, I got the last parts to Kip a few months ago, so he was finally able to finish it. You’ll get to see the completed bike in an upcoming issue. But let’s get back to our magneto install: Morris started making magnetos back in the ’70s, after Harley stopped offering them on its bikes. I ran a Morris mag on my 1967 XLCH 80″ Ironhead stroker back in the 1970s and ’80s. Running a mag eliminates the entire ignition system and makes for a clean machine, wiring- and black box-wise, since it is a completely self-contained system. A magneto even generates its own power, so you don’t need a battery or charging system to keep the engine running.

The M5 magneto we’re going to show you how to install today has a full-field, rare-earth magnetic rotor with composite construction that’s clad in a stainless steel shell. This gives you a super-light, durable rotor to generate the power needed for a strong, hot ignition spark. The CNC-machined billet aluminum housing, which is available polished or machined, has all its corners contoured for exceptional styling. And that’s no surprise since the housing was designed by Dave Perewitz of Cycle Fabrication. The billet gearcase housing has been made to H-D Engineering Department specs, so the correct model M5 will bolt up to any H-D engine without modification. Another improvement is that there are no external coil mounting screws, so the housing is hermetically sealed against moisture. The M5 also boasts a breather system, which helps to separate air and oil, keeping the magneto’s internals clean.

As for those easy starts, modern Morris mags use Morris’ balanced impulse coupling system, which works with both kick and electric start setups on any size motor. When I used to be a piston-engine aircraft mechanic, the dual magneto ignition systems on those engines always ran impulse couplings to facilitate easy and dependable starts. When the starter, be it kicker or electric, turns the engine over, the magneto’s rotor also spins to generate the power needed to fire the spark plugs. The faster the magneto’s rotor is spun, the stronger the spark produced. However, the most critical time is just before the ignition system’s triggering device breaks the circuit, which is when the high-voltage from the ignition coil is sent to the spark plug. To increase the power of the spark, the Morris impulse coupling, which is spring loaded, winds up and then snaps forward just before this important point of the magneto’s rotation to quickly spin the magneto’s internal generator. The result is an intensely hot spark; one much more powerful than what you could get by just using your leg or even an electric starter.

The accompanying photos show Andrew Rosa of Rosa’s Cycle Shop installing a polished M5 Morris magneto onto my Shovel engine. Keep an eye out for my finished boardtracker! We hope to have it featured in the magazine very soon.

But then, you know how my projects usually go…..



Morris Magneto

103 Washington St.

Morristown, NJ 07960



Rosa’s Cycle Shop

540 New York Ave.

Huntington, NY 11743



This story originally appeared in the August 2011 issue of American Iron Magazine, and features step-by-step instructions with photos. To order a copy, visit