This isn’ t your run- of- the- mill Twin Cam. It has two front cylinder heads with forwardfacing exhaust ports, and everything but the cases was made by Feuling. The custom headers have Feuling’ s AR chambers.
of Feuling’ s W3 cylinder heads. Developed by Jim Feuling in the late’ 90s, the W3 was a 3- cylinder Twin Cam engine – a V- Twin with an extra cylinder added – that displaced 150ci( 2,458cc) and made 150 hp and 195 lbft of torque. It was originally developed in conjunction with Harley- Davidson, but the Motor Company bowed out before the W3 reached its final stages of development. By the time Feuling passed away in 2002, only a small number of W3- powered motorcycles had been built.
“ We had a set of the W3 cylinder heads,” explains Leatherman, who worked for Jim Feuling and now owns the company that still bears the founder’ s name.“ We really wanted to take this FXRT and turn it into a twin- carb Twin Cam engine. We had a special set of conversion cases that have the Evo mounts that allow you to build a Twin Cam engine. Outside of the cases, everything else is made by Feuling, from the cylinders to the heads to the 594 Race Series Camchest Kit.”
The W3 heads have Feuling’ s big- bore cylinders with a 4- inch bore and a 4- inch stroke, for a displacement of
107ci. The heads have Figure 8 combustion chambers, an 11.25:1 compression ratio, 2- inch intake valves, and 1.65- inch exhaust valves, and the engine cranks out 120 lb- ft of torque.
A unique thing about Feuling’ s Twin Cam is that its W3 cylinder heads are both front cylinder heads, with both exhaust ports facing forward so they get more airflow than having one rear cylinder head with a rear- facing exhaust port. The team fabricated a unique exhaust system, which includes Feuling’ s patented Anti- Reversion chambers in the head pipes and dual exhaust pipes with dogball baffles.
A stock Harley has both the intake and exhaust on the right side of the engine, but Feuling’ s twin- carb Twin Cam FXRT has the dual exhaust on the right side and a fierce- looking pair of intake manifolds with two Keihin 39mm
FCR carburetors on the left side.
32 | OCTOBER / NOVEMBER 2025 | AMERICANRIDER. COM