This is a short and super-sweet announcement. Not only did JIMS develop an American Made, kick-ass twin cam Monster engine configuration with 131-inches of power, but it's approved by the factory and available through your local dealership. Hang on, there's more. They also developed a set of crankcases to allow any rider to install a 131-inch Twin Cam JIMS engine in an Evo frame back to 1991. Incredible.

Following are all the specs and info:

EVOLUTION MOUNT TWIN CAM RACE ENGINE

JIMS R&D Department has developed 131” and 120” Twin Cam Race Engines that bolt directly into Evolution motor mount style frames. Now the reliability and performance of Twin Cam technology is available for most OEM Harley-Davidson applications back to 1991, as well as most custom frames for Evolution engines.

Engineering

Valve Train: Valve train loads are much higher in a racing engine like the JIMS 131” or 120” than a stock Harley engine. Cam lobe designs are more aggressive with higher lifts and acceleration rates. Valve springs must have higher rates and seat pressures for reliable control. And, these heavier, stiffer and more aggressive parts must run at high rpm. JIMS has been developing and manufacturing racing-quality valve train parts for decades and is using this experience in the JIMS Race Engines Kit.

Tappets: JIMS manufactures its proven PowerGlide II tappets to very high standards of fit and finish. The very close fit between the tappet body and hydraulic unit ensures that the tappet stays pumped up under the stresses of high rpm use. There is no higher quality tappet.

Rocker Arms: JIMS Roller Rockers overcome another racing valve train difficulty – side loads on valve stems and valve guides. High rpm and heavy valve spring pressures can result in high side loads which; in turn, accelerates wear. JIMS roller- equipped rocker arms reduce this loading.

Connecting Rods: JIMS connecting rods are enormously stiff, strong and reliable. They are forged from race- proven SAE 4340 steel. Every surface is then machined in CNC work centers to ensure that both static and dynamic balancing meets engineering design standards. The various heat treat, machining and grinding procedures are carefully followed by JIMS dedicated and independent inspection team to ensure the highest quality final product. JIMS also has exclusive use of the standard Harley-Davidson crank pin and crank pin bearings. These are the highest quality connecting rod bearings available.

Timken Bearing: JIMS uses the traditional Timken tapered roller bearing assembly on the left side of the JIMS engines. This bearing is more tolerant of the crankshaft flexing that is normal at high rpm. Experience in the field indicates that this traditional Timken back-to-back set is more durable.

Engine Cases: The JIMS Race engine cases are stronger, tougher and more versatile than a stock engine case. We didn’t simply add metal here and there. We considered the greater load requirements of the larger racing engine and designed accordingly. Our case set has thicker walls, stronger stud bosses and, larger radius corners.

131″ TWIN CAM RACE ENGINE

The 131" features the same stroke as the JIMS 120" at 4-1/2”, but carries a larger bore diameter of 4-5/16". JIMS R&D Team has added many new features to further enhance the performance of this engine. The first step was to increase air intake into the 131” with CNC Ported Heads which were developed to flow air effortlessly. Next, we upgraded the oil pump to the high flow design found in all current production Harley-Davidson Twin Cam Engine Throw in a brand new JIMS Billet Cam Support Plate, which utilizes the new Harley-Davidson hydraulic cam chain tensioners, and finish it off with the latest in high-performance tappets, JIMS Powerglide II. As always, power delivery is as smooth off the bottom end as stock, with a wide powerband of roll-on punch. These enhancements, plus 130HP** and 135ft-lbs** of torque, take the 131” to an unmatched level of performance and reliability.

HIGH PERFORMANCE COMPONENTS INCLUDES
• Screaminʼ Eagle® Adjustable Pushrods
• ARP® Cylinder Studs
• JIMS® Pressed Flywheel Assembly
• H-D® Hydraulic Cam Chain Tensioners
• JIMS® Billet Cam Support Plate
• JIMS® Roller Rockers
• H-D® High Flow Oil Pump
• Screaminʼ Eagle® Cams
• JIMS® Forged Pistons
• Screaminʼ Eagle® Valve Springs
• JIMS® Powerglide™ II Tappets
• CNC Ported Heads
• Connecting Rods: 4340

131” TWIN CAM® RACE ENGINE SPECIFICATIONS
• Horsepower: 130** • Cam Lift: .635”
• Torque: 135**
• Compression: 10.5:1 • Recommended Octane: 91
• Intake Valve: 2.080“
• Bore Size: 4.313” • Case Material: A356-T1
• Stroke: 4.500

120″ TWIN CAM RACE ENGINE

Delivering 125 HP** and 121 ft-lbs** of torque is just the beginning. JIMS® thick-walled cases offer unmatched strength and are able to support a bore size of up to 4.800. This engine features pressed flywheels, forged pistons, Screaminʼ Eagle valve springs, forged 4340 steel connecting rods and the latest in high performance tappets, JIMS Powerglide™II. From the ground up, this engine has everything needed to stop the competition in its tracks, and the track is what this engine was designed for. Since 2004, JIMS has set the standard in High-Performance Twin Cam Racing Engines, and we are just getting started!

HIGH PERFORMANCE COMPONENTS INCLUDES
• JIMS® Forged Pistons
• Screaminʼ Eagle® Valve Springs • Screaminʼ Eagle® Cams
• Screaminʼ Eagle® Adjustable Pushrods• ARP® Cylinder Studs
• JIMS® Pressed Flywheel Assembly
• JIMS® Roller Rockers
• JIMS® Powerglide™ II Tappets

120” TWIN CAM® RACE ENGINE SPECIFICATIONS
• Horsepower: 125**
• Torque: 121**
• Bore Size: 4.125”
• Stroke: 4.500”
• Compression: 10:1
• Cam Lift: .635”
• Intake Valve: 2.080“
• Case Material: A356-T1
• Connecting Rods: 4340
• Recommended Octane: 91

**Horsepower and Torque performance measured at the rear wheel with a Dynojet® Dynamometer. Your results may vary based on E.F.I. Induction (Non-carburated), camshaft and exhaust combination. This is not a street legal engine.