I had The Harpoon do a rendering of what I wanted the bike to look like when finished. So far, it’s taking on the shape of a street tracker pretty nicely. The paint may change but this should give you an idea.
Revolution Performance’s 1,250cc Big Bore Kit includes two 3-9/16-inch bore nickel-silicon-carbide aluminum cylinders, two 10:1 forged dished pistons, pins, clips, rings, and head and base gaskets.
A set of Harley’s SE .536 Performance XL cams and lifters were also used for this project.
And buttoning everything up nice and tight are Cometic’s high-performance gaskets.
1 To start the installation, Eric rolled the tracker onto the lift and began by removing the carburetor since it will not be reused. He then removed the front and side motor mounts.
2 The rocker box covers were then removed in order to inspect and check the wear on the stock pushrods. Eric says that because they were in good shape it was OK if they were reused with the new components. The rocker boxes were then removed.
3 Next to come off were the cylinder heads. After all the pushrod tubes were removed, Eric removed the cylinder heads, then packed them up and shipped them to Revolution Performance for porting, polishing, and new valve and valve springs installation.
4 Once the heads were removed, the stock cylinders were removed…
5 …followed by the stock pistons.
6 After removing the top-end, the Sweet Tracker sat in this state for a little while until Revolution Performance sent the revamped heads back to Bennett’s.
7 Once the refreshed heads arrived, Eric and I inspected Revolution Performance’s work and everything checked out. The deck surfaces were cut (A), and the combustion chambers/valve seats were reshaped (B) to make room for the new valves and valve components (guides, seats, and springs).
8 The intake and exhaust ports on both heads were ported and polished as well so that air enters and exits the engine in the most optimal way.
9 The .600 lift valve springs were mated with these specific valves used in this application. RevPerf has an in-house flowbench where these heads and their new components were rigorously tested.
10 After dabbing some assembly lube on the Screamin’ Eagle cams, Eric installed them one at a time, lining up each cam’s timing marks.
11 As you can see, the timing marks (arrows) must be lined up in order for installation to be accurate.
12 With the cams in, Eric installed the Cometic cam cover gasket and re-installed the cam cover.
13 Eric wanted to install the new Screamin’ Eagle tappets (lifters) before moving on to cylinder installation. He made sure to lube the lifters excessively before installing them.
14 After he installed the lifters, he tightened the lifter blocks to factory spec.
15 Next, Eric needed to check the clearance of the piston rings to the RevPerf cylinders with a feeler gauge. He did this by taking the piston rings and placing them in the cylinder bore. This step should never be skipped. Eric says that if the pistons are smaller or larger by thousandths of an inch, the consequences can be dire.
16 The oil rings needed to be shaved just a tad, so he removed some material with a bench grinder. He then test fit them in the bores again and everything checked out so he moved on to installing the cylinders.
17 Eric installed the pistons onto the rods with the provided piston wristpins and circlips, and slid the cylinders down over the rings simultaneously. He dabbed assembly lube on the piston skirts for when the bike’s initially started.
18 With the cylinders and pistons installed, Eric placed the cylinder gaskets atop the cylinders since he was ready to install the new heads.
19 One at a time, Eric installed the reworked heads onto the cylinders. Eric says it doesn’t matter which cylinder head is installed first. Every mechanic has his own method of doing things. Eric started with the rear head.
20 Some test fitting of the stock pushrod tube covers to see if they’d clear RevPerf’s cylinders’ fins. No problem. I took some Scotch-Brite to the pushrod covers since I wanted to get rid of any bit of chrome on the bike.
21 The pushrod tube covers fit so Eric installed the other head and torqued the heads to factory spec.
22 Back on went the intake manifold…
23 …followed by the stock pushrods.
24 With the stock pushrods back in place, the rocker boxes were re-installed and the engine was buttoning up nicely. The only thing left for this installment…
25 …was to button up the rocker box covers.
26 Overall, installation was a snap thanks to Eric. The two-tone finish is definitely cool and hopefully the 1,250cc bump will make some good power. Next month, we’ll bring you the dyno results after we install the SuperTrapp pipes, Daytona Twin-Tec ignition, and Mikuni HSR42 carburetor. Stay tuned…
Being that the Sportster is considered by most in V-twin land the redheaded stepchild of air-cooled, 45-degree twin-cylinder motorcycles, I wanted to jump right into making it the coolest outcast I could. Over the course of a few issues, I’ve taken a stock 2000 XL883 Sportster Hugger and have been transforming it into a dirt track racing replica, a.k.a. a street tracker. In this installment, I’ll be walking you through part one of this two-part series about the route I chose to hop up my 883cc engine to a more robust 1,250cc engine thanks to Revolution Performance.
Already I’ve spruced up the chassis with necessary components for achieving a street tracker look, but I’ve really been itching to overhaul the stock 883cc engine to a more robust motor by way of a big-bore kit. Since the 883 isn’t the most powerful twin on the block, I wanted to try and remedy that situation by installing Revolution Performance’s 1,250cc Big Bore kit ($999.95), which includes two 3-9/16-inch bore nickel-silicon-carbide aluminum cylinders, 10:1 forged dished pistons, pins, clips, rings, head and base gaskets, all available in your choice of black, black with machined fins, or silver finishes.
Last month we featured the inner workings of Revolution Performance’s services and products available to horsepower junkies. Eric (El Jefe) took a trip to the RevPerf facilities in Plymouth, Wisconsin. Eric’s piece explained the science behind Revolution Performance’s signature nickel-silicon-carbide (NSC) cylinder bore plating treatment, where the nickel acts as the glue that holds the composite together while the silicon carbide provides the wear surface. Silicon carbide is a close second in hardness to diamonds, which improves wear resistance, less friction, and dissipates heat more efficiently. For a more in-depth explanation on RevPerf’s processes, visit hotbikeweb.com.
Revolution Performance also has the guns to handle more in-depth engine modifications from case machining for Timken bearing swaps, but more importantly for my application, headwork. Being that the Sweet Tracker was being treated to fatter jugs and larger pistons, new heads would allow the engine to flow air/fuel to said components more optimally. I sent my stock 883cc heads to RevPerf for larger valves, new valve springs, larger intake and exhaust guides, new valve guide seals, and full CNC machining of the combustion chamber and porting and polishing of both the exhaust and intake ports, all for around $850.
A set of performance, higher lift cams would definitely aid in boosting the ponies as well, and Revolution Performance recommended Harley-Davidson’s Screamin’ Eagle Pro High-Performance XL cams ($274.95) for ’00-later Sportster models. A camshaft’s key feature is its lobes. When the cams rotate, the lobes push up opening the valves via the pushrods and roller rocker arms to allow the air/fuel mixture to enter the engine. The valve springs then push the valves closed. Higher lift (.536 lift in this case), allow the valves to stay open longer, allowing more fuel into the engine. More air is also added via a combination of things: larger diameter cylinder bores, larger valves, and a larger diameter carburetor or throttle body. Whenever swapping to performance cams, or replacing any cams in general, you should always swap the lifters too, so I ordered a set of Screamin’ Eagle Tappets to boot ($269.95).
Cometic Gaskets are made from top-notch quality and the company has been in business for more than 17 years, making a name for itself amongst all of the powersport and automotive industries alike. Cometic uses only the finest quality materials to ensure that your fluids stay where they’re meant to. It seemed like a no-brainer to have the best gaskets on the Sweet Tracker so we ordered up a complete top-end gasket kit for Sportster models.
In this first installment, I’ll delve into installing the Revolution Performance Big Bore kit, the Screamin’ Eagle .536 cams and lifters, along with Cometic Gaskets’ top-end gaskets for the cylinders and heads. Tune in next month, where we finish off the engine with exhaust pipes from SuperTrapp, a 42mm Mikuni carburetor, and Daytona Twin-Tec ignition. Once everything is installed, and the necessary break-in miles for the new engine have been ridden, the Sweet Tracker will be put to test on the dyno. RevPerf claims it should make a substantial increase in horsepower. We’ll just have to wait and see.
We headed over to the performance guru in Signal Hill, California, Eric Bennett of Bennett’s Performance, for the task of hopping up the engine with the new components. Bennett’s Performance has been making stock Harleys go faster for more than 20 years. From ground-up engine builds for custom applications, complete engine overhaul and hop-up kit installations, to minor service and repair work and more, there’s no task that Bennett’s Performance can’t handle. I personally wanted to thank Eric for his expertise and time invested in helping me with this project. Next round(s) are on me! HB
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