Technical note
V4 Steam Engines: Four-Cylinder Phasing in a Compact Model Envelope
How a compact V4 groups four cylinders, smooths torque delivery and integrates coordinated reversing gear.
Read engineering note ↗RW-V4 · Flagship V4-cylinder steam engine
V4 Model Steam Engine for Model Boats
Four cylinders arranged for compact, composed power.
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The V4 at a glance
An official Rocking Whale product.
The RW-V4 is a four-cylinder model steam engine for large model boats and working miniature installations, with selection guidance for 90–150 cm boats.
The RW-V4 is the flagship of the range: four cylinders arranged in a compact V4 configuration, with coaxial linkage between cylinder rows. Its smooth-running character, high torque and detailed CNC rocker components make it a focal point in any miniature installation.
The V4 anchors the Rocking Whale range as its flagship model, giving commercial partners a strong expression of the brand’s compact engineering identity.
- Compact V4-cylinder configuration
- Coaxial linkage for reversing mechanism
- CNC rocker arm and copper-sleeve reversing-shaft support
- Carefully assembled and factory test-run
Live steam operation
Rocking Whale RW-V4 Steam Engine Demonstration
Watch the four-cylinder Rocking Whale RW-V4 live steam engine in operation driving a mechanical load with coordinated valve gear.
Reference data
Technical specifications.
Figures are provided as a selection guide. Specifications are subject to alteration for improvement without notice.
- Configuration
- V4-cylinder
- Displacement
- 12 cc (1.5 cc × 2 × 4)
- Bore × stroke
- 12.2 mm × 12.7 mm
- Speed
- 2800 RPM
- Max. torque
- 2000 gf·cm
- Power
- 0.05 HP
- Engine weight
- 1100 g
- Recommended boat size
- 90–150 cm
- Normal working pressure
- 0.5–2 bar
- Maximum working pressure
- 3 bar
- Product size
- 122 × 117 × 105 mm
- Package size
- 170 × 155 × 140 mm
- Packed weight
- 1500 g
The V4 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-V4.
Technical note
Model Boat Steam Engine Selection: Matching Engine to Hull
How to match miniature steam engines to model boat hulls by displacement, torque delivery, boiler steam capacity, and propeller pitch across 50 cm to 150 cm craft.
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 V4.
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 V4?
The V4 is recommended as a selection guide for model boats approximately 90–150 cm long.
Is the V4 a multi-cylinder model steam engine?
Yes. The V4 uses four cylinders in a compact V configuration and is the flagship multi-cylinder model in the Rocking Whale range.
What is the V4 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-V4 mean?
RW-V4 is the Rocking Whale model designation for this four-cylinder model steam engine.
What makes the RW-V4 four-cylinder engine ideal for heavy scale RC model boats (90–150 cm)?
With 12 cc total displacement, 3000 RPM maximum speed, and four-cylinder torque continuity, the RW-V4 delivers massive turning power capable of swinging large 60–80 mm marine propellers in scale tugboats, steam launches and naval models.
How does the RW-V4 eliminate dead-centre starting issues in live steam operation?
By phasing four cylinders across two 90° banks with overlapping power strokes, at least one cylinder is always under steam admission regardless of crank position, guaranteeing instant self-starting and smooth low-idle stability.