Retrol R31 4.2cc V-Twin Shovelhead Style 4 Stroke Gas Engine Model Gift
Hero Section: The Return of the "Shovelhead" Legend
In the 1960s, a specific engine silhouette changed the look of American motorcycles forever—the "Shovelhead." The Retrol R31 is a faithful miniature tribute to that icon of the highway. With its distinctive rocker box shape resembling the back of a shovel, this 4.2cc V-Twin engine captures the rebellious spirit and mechanical purity of the chopper era. It is more than a model; it is a kinetic sculpture that brings the roar of the 60s to your desktop. Whether you are a mechanic reliving your glory days or a collector seeking the ultimate piece of industrial art, the R31 offers a tactile connection to history that you can hear, smell, and feel.
Why Choose the Retrol R31 Shovelhead?
- Iconic 1960s Aesthetics: This model perfectly replicates the "Shovelhead" rocker cover design, a visual signature beloved by bikers worldwide. It’s a conversation starter that immediately signals a deep appreciation for motorcycle culture.
- Heirloom-Quality Materials: Forget plastic replicas. The R31 is machined from solid brass and stainless steel. The contrast between the golden brass and the polished silver components gives it a heavy, premium feel that exudes luxury and durability.
- Performance-Grade Valve System: This isn't just for show. We have upgraded the internal mechanics with distinct large and small valves for intake and exhaust. This optimization mimics real engine tuning, resulting in better airflow, more power, and a more authentic exhaust note.
- The Ultimate Bonding Experience: Tuning this engine is a ritual. It’s the perfect excuse to spend time in the workshop with a son, father, or close friend, passing down the knowledge of how internal combustion works through hands-on interaction.
Technical Highlights: Engineering Simplified
- 4.2cc V-Twin Power: The large 4.2cc displacement ensures this engine doesn't just buzz—it thumps. The V-cylinder layout provides the classic syncopated rhythm that V-Twin fans crave.
- Functional "Cold Cooling" Fins: True to the original air-cooled design, the cylinders feature deep, precision-cut cooling fins. These aren't decorative; they effectively dissipate heat, allowing for stable operation during longer run times.
- Precision Carburetion: The R31 features a newly designed carburetor with a toggle throttle lever. It offers sensitive response to adjustments, allowing you to fine-tune the air/fuel mixture for that perfect, slow "potato-potato" idle.
- CDI Reliability: While the look is vintage, the ignition is modern. The CDI electronic ignition system ensures a strong spark every time, making the engine beginner-friendly and reliable.
Specifications
- Brand: RETROL
- Model: R31 Shovelhead Style
- Material: Brass / Stainless Steel
- Scale: 1/5
- Displacement: 4.2cc
- Bore: 13mm
- Stroke: 16mm
- Dimensions: 150 x 120 x 140mm
- Weight: 1200g
- Cooling: Air-Cooled
- Ignition: CDI Electronic Ignition (Requires 3 x AA Batteries)
- Spark Plug: 3/16-40 Inch Thread
- Fuel: 95# Gasoline
- Lubrication: Mixed Fuel (Gasoline/Oil = 25/1)
- Oil Type: 2T Engine Oil
- Starting Method: Electric Drill or Manual Pull
Usage Scenario: The Sound of Nostalgia
It’s a quiet Sunday afternoon. You place the R31 on your desk, the brass glinting under the lamp. You prime the fuel, connect the battery, and give the flywheel a spin. The engine roars to life, shaking slightly on its wooden base with raw mechanical energy. As you adjust the throttle, the engine settles into a steady rhythm. For a moment, you aren't at a desk; you're on Route 66. It’s a powerful stress reliever and a mesmerizing display of physics in motion.
Important Tips from the Workshop
- The "Quarter Turn" Rule: If the engine has compression and spark but won't start, the carburetor needle is likely the culprit. Gently tighten the main needle, then loosen it by exactly 1/4 turn. This is the standard baseline for starting.
- Lubrication is Life: This engine uses splash lubrication. You must mix high-quality 2-stroke oil with 95# gasoline at a ratio of 25/1. Never run straight gasoline, as it will seize the piston.
- Break-in Matters: The upgraded valve system and piston rings need time to seat. The engine will run smoother and cooler after the first few tanks of fuel.
- Safety: Always turn off the power switch immediately after the engine stops to protect the ignition module.
Customer Support
We are passionate about keeping the spirit of these engines alive. If you need assistance with tuning, spare parts, or maintenance advice, please contact our expert support team at service@helloworld7.com.
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