It seems like no matter how powerful and fast our motorcycles are, we just can't resist the urge for more. You can increase the compression, flow the heads, juice up the cams, add nitrous or a blower-you get the idea. Nobody should have to settle for what took the Factory engineers years, if not decades, to design, hone (no pun intended), and perfect on our beloved machines. Size matters to us, from the duallies we drive to the 24-ounce ribeye down at BeefBarn.
Aside from the simple pipe/airbox modification, probably no other job is easier to perform or gains the greatest bang for the buck than increasing the displacement of the motor. Many companies produce big-bore pistons that work well with most of the stock H-D components. Combine the increase in cubic inches with a slightly more aggressive cam design and the aforementioned pipes and air cleaner, and you can have yourself a very dependable, streetworthy motor. Streetworthy means the bike has the torque where you want it, most likely in that sweet 2-4,000 rpm midrange where we spend most of our time. Combine that with reliability and the bike is going to be fun to ride. On the flip side are motors built for peak (high rpm) power numbers that often give up power in the low rpm range while reducing reliability and possibly running poorly on pump-gas.
Kuryakyn has all the bases covered as far as motor hop-ups are concerned. Their individual components and motor kits range from mild to wild. As the parts get more aggressive (as in high lift cams, billet heads, larger throttle bodies, etc.) they yield more power, but at an expense, not the least of which is economic. We contacted Kryakyn to see what they had for the more budget-minded consumer that seeks more power but still wants to retain stock-like rideability and reliability. We were starting with a stock 96ci '07 Softail Deluxe that we wanted to bump up in size. They came up with the Cheap Thrills kit that fit the bill and in the process would increase displacement to 103 inches. Before we get into the specific parts, the following are the reasons we went with Kryakyn: gains in power and torque, a wide, usable powerbands easy starting without compression releases, quiet and smooth operation, can run on 91 octane pump gas without detonation (pinging), and performance-matched components.
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1. Before installing the rings on the pistons, we inserted each ring squarely into the cylinder and measured the end-gap of each ring with a feeler gauge. We were looking for 14-16 thousandths of gap. Too little end gap may cause the piston to scuff the cylinder and/or seize. Too large of a gap leads to high oil consumption and exhaust blowby.
1. Before installing the rings on the pistons, we inserted each ring squarely into the cy
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2. We found the rings to have too small a gap, so they were opened up a bit with a rotary ring file.
2. We found the rings to have too small a gap, so they were opened up a bit with a rotary
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3. Following placing the rings on each piston Matt placed each piston atop their respective rod before inserting the wristpin and securing the piston with a circlip on either side. Each circlip snaps into a groove that's machined into the piston.
3. Following placing the rings on each piston Matt placed each piston atop their respecti
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4. ... inserting the wristpin and securing the piston with a circlip on either side. Each circlip snaps into a groove that's machined into the piston.
4. ... inserting the wristpin and securing the piston with a circlip on either side. Each
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5. Before sliding the cylinder down over the piston, the rings were compressed with a ring compressor tool. We also made sure to put the O-ring on the bottom of each cylinder. This replaces the older style base gasket.
5. Before sliding the cylinder down over the piston, the rings were compressed with a rin
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6. The same procedure was followed for the rear cylinder assembly. You can see in the bottom of the photo magnetic holders that hold the lifters up and out of the way.
6. The same procedure was followed for the rear cylinder assembly. You can see in the bot
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7. Before putting on the heads we placed Cometic MLS (Multi-Layer Steel) Head Gaskets on top of the cylinders. These gaskets are made of three layers of stainless steel, with the outer layers embossed and coated with Viton rubber. The center layer gives the gasket strength and is designed to move with the head both vertically and horizontally to maintain a good seal. We used 0.040-inch gaskets but they are available in various thicknesses. We torqued each cylinder head to factory specs.
7. Before putting on the heads we placed Cometic MLS (Multi-Layer Steel) Head Gaskets on
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8. Before finishing the top end we tackled the cam chest area. The first thing we did was line up the timing marks (indented dots) on the camshafts before pressing the cams with the chain into the cam plate.
8. Before finishing the top end we tackled the cam chest area. The first thing we did was
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9. Once installed in the cam plate, both were inserted into the right side engine case. The ends of each cam sit in bearings in the engine case.
9. Once installed in the cam plate, both were inserted into the right side engine case. T
The parts we received consisted of:
• Wild Things 103ci Forged flat top pistons, rings, pins,
clips #458 | $329.99 |
| * Wild Things TC-2D cams #460 | $349.99 |
| * Fast Times Pushrods # 438 | $124.99 |
| * Pro "R" Hypercharger # 9322 | $309.99 |
| * Bluegrass Breather # 9932 | $49.99 |
| * Catch Tank (for Bluegrass Breather) # 9931 | $49.99 |
| * Top End Gasket set # 480 | $89.99 |
| * Cam Service Gasket set # 481 | $29.99 |
| *.040-inch MLS Head Gaskets # 485 | $36.99 |
| * Wild Things Copper Exhaust Gaskets # 482 | $7.99 |
| Parts totaled | $1,379.90 |
The previous Big Bore Cylinder Honing story in this issue showed you how we took the stock 96-inch cylinders and bored and honed them to accommodate the larger 103 pistons. Once that was finished we took the Cheap Thrills parts to Harley-Davidson of Anaheim-Fullerton to have tech Matt Cortez rebuild the motor and install a set of Vance and Hines Long Shot pipes, along with a Power Commander. Once the bike was put back together, we put 1,000 miles on the bike before dyno-tuning the EFI to gain maximum power.
Check out how what can be done in a day's worth of wrenching.