Hopefully I can add a little more to Gingerfold’s input.
The L2 designation can be interpreted as follows, “L” is for ‘vertical engine’, the “2” denotes a particular cylinder size, i.e. the bore and stroke (1.4 litres cyl). The basic design had a sump located crankshaft, with a separate crankcase/block assembly and separate heads. (There were many marine and automotive car engines of that era built along similar lines).
The L3 and later L3B engines were therefore one cylinder size up from the L2. ( At 3 litres per cylinder!)
Once the bus and truck operators noted the general performance and efficiency of the engine they obviously asked for a lighter engine to be designed.
The LW was therefore produced to meet this market. The LW designation standing for vertical / lightweight.
At this point the new aluminium crankcase became the major weight saving area and it also incorporated the crankshaft, the oil ‘sump’ therefore became just that, a receptacle for the oil only.
The LX came along around 1956. It was a direct descendant of the 6LW, but, with a larger bore/stroke giving 1.74 litres cyl. The cylinder block became a single casting rather than the two of the 6LW. The 6LXB was an upgrade to the 6LX with minor mods to fuelling and RPM up to 180 BHP. 8LXB’s gave 240BHP.
For the truck market the LXC was produced in 1978 which was an update of the 6LXB to 201 BHP, approx 3000 produced.
The 6LXCT was a direct derivative of the 6LXB ( n.b. not the 6LXC! ), with an increase to 230BHP, the PSV spec went up to 242 BHP for horizontal engines to meet coach legislation. An 8LXCT version gave 265 BHP.
The 6LXDT was a further derivative along the same lines but with major design changes to give 2.1 liters cyl and 270 BHP.
The 6LYT was an all new (Metric) design of 15.5 litres with a rating of up to 350BHP, with 2 valve heads. The 6LYTi was also produced for the marine market.
The LG1200 was the last ‘new’ engine at 12.7 litres, and, was precisely what the 6LXDT should have been in the first place. It was an amalgam of the LXDT and LYT being a more compact design with all the “iffy” bits addressed.
Just when you start to think your product can properly meet a number of market sectors then along come the politicians deregulating the bus industry, your truck customers get swallowed up, fishing quotas decimate boat building
and the boss says ““How much■■? you must be joking!”” (to meet the next round of emission legislation )
In retrospect, anyone in the business of selling loose diesel engines into the automotive market place have been under severe pressure for the past 25 years due to the volumes necessary to fund new designs, keep up with legislation etc and the general demise of their market place over that period, i.e. AEC, Bedford, ERF, Atkinson, Leyland, Bristol, Daimler, etc, etc. Never Forget, hindsight is always 100%!!!
