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 EngineThrow in a brand new JIMS Billet Cam Support Plate, which utilizes the new Harley-Davidsonhydraulic 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.

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Editor's Note:Following is a hot-shot memorandum containing break-in recommendations by the crew of Crazy Horse Engines, the builders of a truly unique V-Twin engine. The Bikernet staff is building a 5-Ball Factory Racer, using a 100-inch Crazy Horse Engine. Some aspects in the following tech might not match your engine configuration, but they remain solid break-in notions for any new V-Twin engine.

Many of these shots came from Brass Balls Bobbers since they use Crazy Horse Engines in many of their bobber models.

Before starting the engine for the first time make sure that there's a solid column of oil in the feed (suction) line to the bottom of the oil pump, NO AIR POCKETS, otherwise it will be very difficult to achieve oil prime.

* DO NOT PRESSURIZE OIL TANK WHILE THE HOSE IS CONNECTED TO THE PUMP *

You may wish to temporarily loosen the tappet screen plug in order to “burp” any air.

NOTE – Crazy Horse Engines require premium gasoline (octane 91 or higher) for best performance.

CAUTION – Low octane gasoline and hot weather can cause detonation and extensive engine damage. Never try to power through ignition knock (“ping” “rattle” etc.) by opening throttle.

CAUTION – If engine is run with foreign material in the oil tank, engine damage will occur. Engine damage caused by foreign material in the oil tank is not covered under the Crazy Horse warranty. Clean oil tank and oil cooler and flush or replace oil lines before installing engine in frame.

Engine Break-In Procedure

Note: Correct break-in will assure longer engine life and will prevent unnecessary engine damage. Engine damage caused by improper break-in or installation is not covered under the Crazy Horse warranty.

A. Initial start up: Run engine approximately one minute at 1250-1750 rpm. DO NOT crack throttle or subject to any loads during this period as head gaskets are susceptible to failure at this time. During this time, check to see that oil pressure is normal, that oil is returning the oil tank, and that no leaks exist.

B. Shut off engine and thoroughly check for any leaks or other problems. Let engine cool to the touch.

C. After engine has cooled, start up again and allow the motor to build some heat. Engine should be run no longer than three to four minutes. When the cylinders become warm/ hot to the touch (approximately 150°) shut the motor down and let it cool to room temp. Follow the same cautions as for the initial start-up, and continue to watch for problems.

D. Repeat this procedure 3 or 4 times. Each successive time it should take slightly longer to warm up and you can increase the temp slightly each time (+10°). You can be more liberal each time with the rpm, gently vary rpm continuously from idle up to 2500 rpm in the final cycle. Don’t be too concerned with final carb settings at this time because idle speed and mixture cannot be correctly set until the motor reaches full operating temperature. The motor should not reach that temperature during these cycles. Do not allow engine temperature to become excessive. After the motor has cooled to room temperature for the final time you are ready to start the 1000 mile engine break-in process.

E. The first 50 miles are most critical for new rings and piston break-in. Engine damage is most likely to occur during this period. Keep heat down by not exceeding 2500 rpm. Avoid lugging the motor, riding in hot weather or in traffic. Vary the engine speed. Do not lug the engine. We recommend changing the oil at 50 miles.

F. The next 500 miles should be spent running engine no faster than 3500 rpm or 60 mph. Avoid continuous steady speeds, and do not lug the engine. Vary engine rpm. We recommend changing the oil again at 500 miles.

CAUTION – Lugging or running engine prematurely at sustained high rpm may result in damage to pistons and other engine components. Crazy Horse voids it's guarantee if engine is not broken in properly.

G. For the balance of the first 1000 miles the motor can be run in a normal but conservative manner. You can be more liberal with the rpm range and motorcycle can be operated at normal highway speeds. Avoid overheating or putting any hard strain on the engine: no drag racing, dyno runs, excessive speed, trailer towing or sidecar operation.

H. After 1000 miles, verify carburetor jetting and adjustment. Change the engine oil. Motorcycle can now be operated normally.

I. Go out and ride and enjoy all the attention!

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