Technical note
Inline Twin-Cylinder Steam Engines: A Classic Layout for Visible Mechanism
The engineering trade-offs of the inline twin layout, with the Rocking Whale L2 as its documented example.
Read engineering note ↗RW-L2 · Classic inline twin-cylinder steam engine
L2 Inline Twin-Cylinder Model Steam Engine
A retro, open mechanical profile with six-bearing crank support.
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The L2 at a glance
An official Rocking Whale product.
The RW-L2 is an inline twin-cylinder model steam engine for working model boats and miniature craft, with selection guidance for 70–130 cm boats.
The RW-L2 pairs a classic inline twin-cylinder silhouette with a carefully supported crankshaft. Its open mechanism and brass construction invite close inspection while providing smooth, stable running for working miniature craft.
The L2 adds a traditional inline profile to the range for customers who value an open mechanism, classic proportions and clearly visible moving components.
- Retro and elegant inline layout
- Six ball bearings supporting the crankshaft
- High-precision CNC-machined parts
- Complete Stephenson valve gear for forward and reverse
Slow motion mechanism
Rocking Whale RW-L2 Slow Motion Demonstration
Watch the inline twin-cylinder Rocking Whale RW-L2 steam engine running in detailed slow motion, showing open valve and crankshaft movement.
Reference data
Technical specifications.
Figures are provided as a selection guide. Specifications are subject to alteration for improvement without notice.
- Configuration
- Inline twin-cylinder
- Displacement
- 6 cc (1.5 cc × 2 × 2)
- Bore × stroke
- 12.2 mm × 12.7 mm
- Speed
- 3000 RPM
- Max. torque
- 1200 gf·cm
- Power
- 0.03 HP
- Engine weight
- 790 g
- Recommended boat size
- 70–130 cm
- Normal working pressure
- 0.5–2 bar
- Maximum working pressure
- 3 bar
- Product size
- 118 × 53 × 97 mm
- Package size
- 180 × 140 × 100 mm
- Packed weight
- 950 g
The L2 in detail
A closer look at the mechanism.
Product, detail, installation and running photographs from the Rocking Whale workshop.
Engineering background
Read the technical notes.
In-depth engineering analysis, historical context, and mechanical principles for the RW-L2.
Technical note
Live Steam Engine Maintenance & Break-In Guide
Essential workshop procedures for running in miniature steam cylinders, selecting compounding steam oils, managing mechanical friction, and long-term storage.
Read engineering note ↗Commercial resources
Evaluate the details.
Use the current manuals and specifications to review the model. Product materials and commercial information are available through a direct enquiry.
Trade & volume enquiries
Discuss the L2.
For distributor evaluation, sample requirements or volume quotations, tell us about your company, market and expected quantity. Contact Rocking Whale for current product price and shipping information for your project.
[email protected] ↗Selection guidance
Frequently asked questions.
What model boat size is recommended for the L2?
The L2 is recommended as a selection guide for model boats approximately 70–130 cm long.
What is distinctive about the L2 layout?
The L2 uses a classic inline twin-cylinder layout with an open mechanism and six-bearing crankshaft support.
What is the L2 price?
Contact Rocking Whale for the current product price and shipping information. Include your project, quantity and destination so we can prepare an appropriate quotation.
What does RW-L2 mean?
RW-L2 is the Rocking Whale model designation for this inline twin-cylinder model steam engine.
Why choose an inline twin-cylinder steam engine like the RW-L2 for RC scale boat models?
The RW-L2 inline configuration features a narrow lateral profile that fits comfortably into long, slender model boat hulls (70–130 cm), offering six-bearing crankshaft rigidity and authentic open-mechanism marine visuals.
How to lubricate and break in the RW-L2 miniature steam engine?
Apply high-grade steam cylinder oil to piston cylinders and light machine oil to all main bearings, crankpins and crossheads. Run the engine on low-pressure air (0.5–1 bar) for 15–30 minutes to properly seat the composite piston rings and sliding surfaces.