Rootes Motor Group built an engine for their trucks which was a design loosely based around an original Sulzer Brothers concept, also copied/licenced by Hills Diesel in the USA. The horizontally opposed engine used a system of rockers to transmit crankshaft motion to the pistons. The engine was a two-stroke diesel with a Roots blower (note that Rootes and Roots were different companies) for scavenging. The engine made its name in the Commer trucks by its screaming engine note, particularly when pulling hard up hills in low gear.
The engine was also developed by Rootes and Lister into an industrial power unit, and a joint company, Rootes-Lister Ltd was set up to market the unit. The sales were not up to expectations and the joint venture was dissolved in the period when Rootes' influence in the car industry was waning rapidly. The illustrations are all from the sales brochure, so we have no control over the colouring!
General view of the engine, showing the Roots blower in the right hand side, the pump and injectors on top, the dynamo and belt and the oil cooler and filter. Access on the Commer truck was not especially good, although I never had to strip any of these engines down, they were quite reliable as long as they were serviced regularly.
Side view of an industrial engine with power take-off and clutch. The starter motor is right underneath the engine, and shares itself with a couple of Petter PH engines, otherwise a unique spec., starter. The clutch and PTO were pretty standard items for Lister, and were also offered on other large engines such as the JP/JK/JS/JA/JW series, and for the smaller air-cooled singles and twins.
Picture of a packaged power unit for gen set applications, with radiator and SAE bell-housing. Although a 'flat' engine, the TS3 was still quite bulky, and did not offer that much of a space advantage over conventional engines, particularly in this case where the radiator was a conventional item and was easily taller than the engine itself. There is no mention of the means of driving the radiator fan, and I assume that the crankshaft had an extension bolted to it to provide a pulley, although the picture hints at a small electric or hydraulic motor. The truck operator's manual shows a small drive take-off on the timing cover with a greaser to lubricate the bearing for the shaft.
An industrial centrifugal fire pump setup, with the engine directly driving the impeller. The inlet manifold and timing cover with injection pump drive are shown well in this only shot of the other side of the engine. The pump is probably Worthington-Simpson or one of the other major pump makers.
The following sequence of illustrations show the various stages of operation of the engine, going through a standard operating cycle. Note that the pistons do not move completely in unison, the timing of the inlet and exhaust ports is not symmetrical and there is a delay between the ports opening and closing.