Live Steam
Stuart B.B. Lightning
Single Cylinder Marine Engine
Complete and Ready to Run

Description

The Stuart BB (Ball Bearing) Lightning is a rare engine, produced between 1924 and 1941 for use in high speed model boats.

Taken from http://www.stuartturnersteam.com/Marine/BB/BB.html:

"This engine is a departure from the normal Stuart engines, most noticeable in its futuristic looks. The use of aluminium for the main body allow for a nice highly polished finish.

The Cylinder is of an over square design where the stroke is shorter than the bore, this increases the speed at the expense of power. The rating of 4,000 rpm makes it ideal for a dynamo or pump. Both of which were catered for with baseplates to fit already available units.

The crankshaft ran in a Ball bearing hence the BB name, reducing wear and allowing the fast operating speed. A large hollow crankpin and counterbalances crank, also improved speed. The closed crankcase allows for wet sump lubrication. Partially filling the crankcase with oil allows for the crank to splash oil all over the crankshaft, bearing, trunk guides, and bottom of the piston lubricating most of the cylinder. This extends to the outside of the crankcase as the eccentric is mounted in an extension bath. The crankshaft leaves the bath through a bearing point lubricated by a pressurised grease fitting (similar to the grease fitting used on the water pump shaft to prevent leakage).

The effect of all these design features is an extremely smooth running engine and free running engine. Almost no vibrations even when running at high speed."

Taken from the auctioneer Bonhams for a Sept 2021 sale of a Stuart BB and Boiler in display case;

"Known as the 'Stuart B.B. Steam Plant', the engine was specially developed for tethered hydroplane racing and straight speed trails. Due to the enormous pressure exerted on the aluminium engine casing, the casing was prone to shatter the engine to self-destruct entirely. It is therefore extremely rare to find surviving engines with the casing intact, with the present Lot thought to be one of seven known examples.

Sold for £4,462.50 inc. premium"

This engine appears to be in excellent and complete condition, see photos, and runs well on compressed air. The engine's gaskets will have to be renewed if run on steam and due to the age of the engine it should not be run at high speed.

Specification;

Type: Vertical, single cylinder, double acting, slide valve.

Design: enclosed crankcase

Bore: 3/4 in

Stroke: 5/8 in

Height: 4 1/2 in

Weight: 28 ozs (0.8Kg)

NOTE: The model steam engines and boilers are NOT children’s toys and should not be assembled or operated by children unless under close supervision of an adult.