As in many previous issues, this month's article kept me covered in aluminum shavings. After all the cutting and welding on the chopped Sporty cases, the motor still needed more material removed so that it didn't look as if it had been chopped-I wanted it to look as if it had been originally cast with a rear Evo-style mount before it was polished. Without the rear transmission housing, the cam-chest cover had to be modified as well, since it didn't fit with the aesthetics of the motor anymore. I had a few weeks to get everything ready for polishing, so I got out the Sawzall; a hand drill; and an assortment of porting bits, grinders, and sandpaper, then started carving, shaping, and prepping my Sportster sculpture.Instead of spending the time and money on modifying my stock 883 cylinders, I called up Revolution Performance for a pair of the company's 1,250cc (76ci) cylinders. This kit allows the builder to achieve the largest displacement possible without boring stock Sporty cases or modifying the heads and pistons-a true bolt-on big-bore kit. As if that weren't enough, the cylinders are all aluminum with an aluminum-nickel-silicon-carbide-plated bore. The bore plating replaces the iron sleeve normally found in a stock cylinder, reducing weight and improving the cooling ability of the cylinder.
Last issue I had the rear...
Last issue I had the rear mount welded to the rear section of the chopped Sporty cases. While Mike (an employee at Orange County Welding) was welding, I told him to make the welds strong instead of pretty.
I started to make the cases...
I started to make the cases pretty with a porting bit and a hand-held drill.
A different-shaped bit was...
A different-shaped bit was used to get at the assorted angles of the cases.
With an angle grinder I removed...
With an angle grinder I removed some of the large, rough edges created by the initial cutting of the cases.
A rasped porting bit removes...
A rasped porting bit removes material at a slower rate than the grinder or the bladed porting tool. It's also easier to control when precise material removal is necessary.
Cleaning up right-angle welds...
Cleaning up right-angle welds requires a special tool. HTP America built a belt sander specially designed for this use, and it works great.
A few hours of work, and I...
A few hours of work, and I had a motor that no longer appeared chopped-and possibly as if it had never been modified at all.
Finally, I used good ol' sandpaper...
Finally, I used good ol' sandpaper and elbow grease to finish it.
With all the aluminum removed...
With all the aluminum removed from the cases, the cam cover didn't look as if it fit anymore, so I had to modify it as well. The red marks on the surface show the first two design ideas I had, but when I was about to start cutting, I changed my mind again.
Here I am pointing to the...
Here I am pointing to the new lines of the cam cover: the border of the gasket surface. The metal surrounding the gasket surface is merely to cover up the oil pump with edges that line up with another cover for the final drive.
Once again, the Sawzall made...
Once again, the Sawzall made quick work of the cam cover.
The sharp edges were tamed...
The sharp edges were tamed with the angle grinder and further smoothed with the flap wheel sander.
A large portion of the cover...
A large portion of the cover is strictly decoration.
And the finished cover, ready...
And the finished cover, ready for polishing.
I mocked up the motor for...
I mocked up the motor for a few teaser pictures of how the motor looked before it was polished, with the original cylinders.
Revolution's Millennium cylinders...
Revolution's Millennium cylinders are aerospace bred, and the perfect fit for the build. These cylinders are bored to 1,250cc and are cast aluminum with a nickel-based cylinder-wall coating instead of the usual iron sleeve. The first major advantage of all aluminum is its ability to hold in less heat, as aluminum cools far more quickly than steel.
Also, Revolution's cylinders...
Also, Revolution's cylinders weigh less than stock cylinders; this stock piece weighs almost 11 pounds.
The Revolution Millennium...
The Revolution Millennium cylinder weighs just over 6 pounds.
The stock cylinders measure...
The stock cylinders measure in almost a half-inch smaller than the 76-cubic-inch total of the Revolution Performance Millennium cylinders.