After securing the motorcycle to a lift, we disconnected the battery for safety.
 We removed the dash panel and gas tank to provide access to the cylinder head hardware.
 The stock inner cam bearing (left) was to be replaced with a full complement component (right), which is stronger than the OE unit for obvious reasons.
 Both inner cam bearing were replaced with the full complement components and the cam case inspected for cracks or other damage.
 Back to the cam support plate. The hydraulic cam chain tensioners were removed for the cam replacement procedure. The cam support plate would be stripped.
 These cams would replace the stock 96-inch cam shafts. The larger 103 displacement requires more air, therefore cam profiles designed to provide better breathing were in order.
 The new cams were checked in the case for proper/adequate clearance. Plenty of clearance here. Earlier Twin Cam cases sometimes required clearances for higher lift cams to spin without interference.
 The new cams were chained up with the timing marks located properly.
 The cam support plate was then installed over the two camshafts. The black plastic devices are installed on the camshafts prior to installing the cam plate to prevent damage or scratches to the bearing races. All the cam plate hardware was installed at this time.
 We installed a new O-ring on the oil pump appendage as shown.
 We carefully reinstalled the georotor oil pump into position in the cam case.
 We instaledl the inner cam chain tensioner onto the cam plate. We squirted a copious amount of oil on all the metal surfaces of the cams and plate assembly prior to installation.
 We slid the cam plates and new cams into place in the cam case.
 We installed the cam plate centering tools (red arrows), then installed and tightened the cam plate hardware. The tools hold the cam plate and oil pump in position during the hardware tightening sequence.
 We installed the cam drive sprockets and checked them for alignment. Spacers are available from Harley-Davidson to provide adjustment.
 The sprockets were perfectly aligned, so the drive chain was installed, and the locking tool positioned to prevent movement while tightening the sprocket hardware. Factory torque specs are called for here.
 The outer hydraulic chain tensioner must be installed at this time.
 On went the cam cover and hardware, which was then tightened to factory specifications.
 Both 103 cylinder bores received a liberal dose of WD-40 (or other lightweight lubricant).
 Before the piston rings were installed on the pistons, the ring end-gaps (all rings) were checked using a feeler gauge.
 We installed the rings in their correct ring lands on the piston. There are two compression rings (top two) and an oil ring (bottom).
 We installed the pistons onto the connecting rods and slid the wrist pin into place.
 Before installing the wrist pin keepers, we made sure the pistons were oriented correctly. The arrow on the top of the piston should be pointing forward. The STD denotes standard bore for 103 pistons.
 We installed the wrist pins using the easy-to-manage wrist pin tool rather than a screwdriver.
 The pistons were installed waiting for their respective cylinders.
 We installed a new O-ring on the bottom of each 103 cylinder. The O-rings are included in every kit.
 We oiled up the wring compressor before using.
 We clamped the ring compressor in position over each piston as shown.
 We carefully slid the cylinder down over the piston pushing the wring compressor down after correctly orienting the cylinder with the push rod reliefs on the right side of the motor.
 We carefully unclamped the ring compressor and removed it.
 Before sliding the cylinder all the way down on the motor cases, we installed new O-rings on the oil drain tubes.
 We repeated the cylinder installation sequence on the rear cylinder. Note the green O-ring in position on the rear drain.
 Both cylinders were in position. The crosshatch was visible on the front cylinder. YES…this motor should be broken-in properly before being ridden hard.
 We installed new head gaskets on each cylinder front and rear.
 We thoroughly cleaned any residual gasket material from the cylinder head mating surfaces.
 We did the same on all the gasket surfaces of the rocker boxes.
 We installed the cylinder head, throttle body assembly onto the new cylinders as a unit, the same way it was removed.
 We installed the cylinder head bolts into all the holes. Don’t forget any!
 We carefully torque-tightened all the cylinder head bolts using the pattern and torque spec found in the H-D manual for our specific application.
 We installed new rocker box gaskets front and rear.
 We thoroughly cleaned the gasket mating surfaces, then installed the lower rocker box onto the cylinder head.
 Using an inch-pound torque wrench, we tightened all the lower rocker box hardware to factory torque specifications.
 We installed new O-rings in the lifter covers as shown.
 We installed new internal O-rings where required in all four of the pushrod tubes.
 New O-rings are also required at the top of the push rod tube where it seats in the cylinder head.
 We installed the pushrod tubes, then the pushrods in the same locations from where they were removed. We marked them, didn’t we?
 New and improved breather assemblies were included in the gasket set with the 103 kit. Old on top, new on the bottom.
 We installed the rocker support assemblies onto each cylinder head including the new breather units.
 We tightened the hardware holding the rocker blocks in place.
 We re-installed the exhaust system at this time.
 The rocker support was installed. Note the upgraded breathers.
 We finished tightening the exhaust system hardware. The green tape was holding the flanges in place.
 We plugged in both exhaust pipe O2 sensors.
 We made sure ALL FOUR lifters were bled down, then installed the pushrod cover clips.
 We installed and tightened the rear exhaust mount equipment.
 We tightened the breather bolts.
 We installed new rocker cover gaskets front and rear.
 We installed the rocker covers and tightened the rocker cover hardware.
 After ensuring the lifters had bled down, we installed the pushrod cover clips.
 We plugged in the throttle body control cable.
 We re-installed the top front motor mount (heim joint) and coil-coil bracket.
 We re-installed the air cleaner cover. It says 96, but we knew it was 103.
 We re-installed the gas tank and dash cover, connecting all the required leads and plugs.
 We reconnected the positive terminal of the battery.
 We re-installed the seat and tightened that bolt.
 This Road King was ready for the road. It had new rubber installed front and rear before it left the lift. If you’re looking to convert your 96-inch Twin Cam to 103 cubic inches, one of the best places to have that done is your local Harley-Davidson dealer.
Harley-Davidson’s official performance product line known as Screamin’ Eagle continues to expand as customer feedback tells the Motor Company what riders want for their street machines. They want more horsepower, more acceleration, and more cubic inches.
If you’re riding a 2010-or-earlier Harley-Davidson big twin, it was more than likely sold with the then-standard displacement of 96 cubic inches, or even earlier models with 88 inches. Don’t be sad. It’s easy to convert your 96 inches or less into a 103ci machine when using a Screamin’ Eagle street-legal kit to do so. Having your local dealer perform the swap makes it very convenient as well. You don’t even need to get your hands dirty.
Chris Meyers, ace tool swinger at Black Hills Harley-Davidson in Rapid City, South Dakota, performed this conversion in about three hours. What you’ll see in the following photo sequence is the 96-to-103 upgrade Stage II kit being installed, which included new cam shafts and full complement inner cam bearings, all of which are included in this kit. B