s good as that stock Harley-Davidson Twin Cam engine is, in certain areas it can use a little help. The oiling system, for instance. OE, the Twin Cam uses a pretty small crank-speed gerotor style oil pump with gears preloaded against the cam support plate and the pump housing itself. All that preloading causes lots of friction and wear. Couple that with the Twin Cam’s crankshaft and its machined “paddles” that provide a trigger for the crank position sensor (CPS). Those paddles do a great job of whipping up any unscavenged oil, turning it into a thick, foamy froth. It’s not a model of efficiency. To be fair, Harley did address these shortcomings somewhat with a new style, higher volume/higher pressure oil pump introduced in the ‘06 Dyna and then fit to all later model engines. It was a step in the right direction–but more could still be done.
     Now take a look at the Feuling Oiling Systems. Feuling has tackled those Twin Cam oiling woes with a vengeance. Taking a “system approach” to the problem, the Feuling upgrade kits include a 6061 billet aluminum high-volume oil pump, a 7075 billet hard-anodized cam plate, a set of tight-tolerance HP + hydraulic roller lifters and all the necessary gaskets for installation. This parts combination increases oil pressure, oil volume, oil flow and oil scavenging and eliminates wet sumping. And the Feuling system not only delivers more oil, with its advanced design it delivers cooler oil. That significantly prolongs engine life and reliability. This much more efficient Feuling system can also increase rear wheel power by as much as 3 horsepower and 4 lbs./ft. of torque.
     In the earlier ‘99-‘06 applications the Feuling oil pump increases pressure volume by a whopping 40-percent and scavenge (return) volume by 60-percent. Feuling’s new style oil pump for ‘06 Dynas and all later model Twin Cams increases pressure volume by 20-percent and scavenge volume by 30-percent. In both cases the increase in pressure volume reduces lifter and valve-train clatter, lowers cylinder head temperatures and increases engine oil pressure overall. The increase in scavenge volume greatly reduces engine blow by, eliminates that “frothing” situation and turns the Twin Cam into a true dry sump engine.
     Everything here is top quality. The Feuling oil pump bodies are aerospace billet aluminum with high-flow 4140 heat-treated chrome moly gerotor gears inside. The design does away with that power robbing friction washer, too. The replacement cam plates are much stronger and harder than the factory parts and the HP+ full travel hydraulic roller lifters are an upgrade, as well. They hold much tighter internal tolerances than OE for a slower bleed-down rate to better handle heavy valve spring pressures. Everything’s been dyno-developed and track tested to provide maximum power, reliability and longevity.
     A Twin Cam’s oiling system can become a model of efficiency–when it’s given the right parts for the job. The Feuling Oiling System Kits contain all those parts.      Everything is here for a bolt-in replacement and a system that will provide increased oil supply, increased scavenging, cooler oil and at the center of it all is that Feuling high-efficiency pump with larger-diameter gerotors. Factor in the Feuling cam plate and lifters and you’ve just optimized that Twin Cam’s weak spot with a truly balanced oiling system. It’s all in stock at Drag Specialties.