Lunati Cams and Feuling Cam Plate Install

Here are the parts we were going to use to upgrade the lower end of the Fat Boy; Feuling pushrods, HP+ Oil Pump, and Cam Plate, and Lunati cams and lifters.

Here are the parts we were going to use to upgrade the lower end of the Fat Boy; Feuling p

Lunati may be a new name in the mouths of the American V-twin market, but it is no stranger to creating parts that generate good engine performance. With a fresh line of camshaft applications available to fit most any Twin Cam Harley-Davidson from ’99 on up, we thought the time was ripe to take a closer look at the company’s offerings and put them to the test. Starting with an extremely low mileage ’04 Fat Boy still sporting its Stage 1 intake and exhaust additions and 88ci displacement, the decision was made to keep the modifications similar to what many would do to their own bikes. This install was designed to best showcase what the parts would do for you and is not about making the most power as possible from the package.

With that in mind we managed to stay rational and chose a pair of Lunati’s camshafts ($265.99) that top out at .510 inches of lift with the stock rockers and did not require changing the valve springs. A matching four-pack of hydraulic roller lifters ($14.99 ea.) was ordered to go along with the new bumpsticks. Knowing the added stresses on the original cast cam plate can get quite high with larger camshafts, we placed a call to Feuling for one of its much stronger 7075 billet cam plates ($399) to support the additional power. A HP+ oil pump ($425) from Feuling should give us a solid rise in oil pressure and oil return scavenging to keep the rotating parts alive for a long time to come. Additionally, Feuling supplied us with a set of adjustable pushrods ($239), saving us the added labor time of pulling the fuel tank and disassembling the rockers. Our Fat Boy guinea pig was an EFI-controlled machine so Dynojet’s Power Vision was chosen to program the Harley’s ECM with the correct information on fuel and timing for the new power combination.

1 To get started Dustin set the Fat Boy up on a lift and removed the air cleaner and Pro Pipe exhaust system. Since we were installing a set of adjustable pushrods, the stock pushrods were simply cut out using a large set of bolt cutters. This method made for a clean cut with no worry about metal shavings dropping into the engine.

1 To get started Dustin set the Fat Boy up on a lift and removed the air cleaner and Pro

In the capable hands of Clarke and Dustin Dunlap at F’NA Cycle and Performance in San Bernardino, California, our H-D was transformed into a much more potent riding machine. Hills, passengers, freeway passing, and stoplight action was much improved and tickets were easily just a twist of the wrist away. Before tearing into the Fat Boy with its open air cleaner, Vance & Hines Pro Pipe fit with a competition baffle, and a factory Stage 1 EFI download, the bike managed to put down a respectable 72.1 horsepower and 77.5 lb-ft of torque as a baseline. With the Lunati cams and a custom tune from Patrick Daniels at Dynojet, those numbers rose to 79.8 horsepower and 84.5 lb-ft of torque. That was a step up of 10.7 percent horsepower and 9.1 percent torque with similar increases across the spectrum. Those numbers were about what we expected and made a difference in the bike’s feel when the throttle gets rolled open. HB

2 With the 10 fasteners removed, the cam cover was pulled free exposing the stock cam plate and camshafts. Dustin was sure to have a catch pan handy because plenty of oil was still setting in the cam chest.

2 With the 10 fasteners removed, the cam cover was pulled free exposing the stock cam plate and camshafts. Dustin was sure to have a catch pan handy because plenty of oil was still setting in the cam chest.

23 A K&N filter was chosen by F’NA for its easy cleaning and high-flow capabilities. Still strapped to the dyno, Dustin made a number of pulls to gather the information we were seeking. Some odd things occurred and just proved that a proper combination of parts was key to achieving a smooth and powerful engine. Without a precise EFI tune for this specific parts combination, the F’NA intake lost 2.4 hp at the 5,700-rpm peak, but gained 1.0 lb-ft of torque at the 4,100-rpm peak. That wasn’t the interesting part though. The new intake gained quite a bit way down low where the bike would spend the majority of its time running. At 2,550 rpm, F’NA’s tubular intake made 1.5 hp and 4.0 lb-ft of torque more than the Stage 1. That is a jump that could be easily felt in roll on throttle. Low rpm increases ran from basically zero all the way to the 4,500-rpm mark before the F’NA parts star losing to the Stage 1 breather. Next issue we will delve into the new Power Vision for a more in-depth article on how the unit works.

23 A K&N filter was chosen by F’NA for its easy cleaning and high-flow capabilities. Still strapped to the dyno, Dustin made a number of pulls to gather the information we were seeking. Some odd things occurred and just proved that a proper combination of parts was key to achieving a smooth and powerful engine. Without a precise EFI tune for this specific parts combination, the F’NA intake lost 2.4 hp at the 5,700-rpm peak, but gained 1.0 lb-ft of torque at the 4,100-rpm peak. That wasn’t the interesting part though. The new intake gained quite a bit way down low where the bike would spend the majority of its time running. At 2,550 rpm, F’NA’s tubular intake made 1.5 hp and 4.0 lb-ft of torque more than the Stage 1. That is a jump that could be easily felt in roll on throttle. Low rpm increases ran from basically zero all the way to the 4,500-rpm mark before the F’NA parts star losing to the Stage 1 breather. Next issue we will delve into the new Power Vision for a more in-depth article on how the unit works.

Source:

hot.bike@sorc.com