Ahh I see you found Trevors site. That's a good page.
The joke is that the 4 cyl engine used in TR2-4As was also previously used in the Furgeson Tractors. (which is true) The engine was produced by Standard, which at the time owned Triumph. So when they were developing the first Triumph sportscars they used the exsisting engine, to save cost. The early TR2s even retained the dual thermostat housing found on the Tractors. and it explains the wet-sleeve design cylinders,and low rev, high torque charecteristics as those were (and are) common features of utility-type engines.
This has also led to the term "TRactor" for the early TR series cars
the first Autin Healeys (100-4) were the same way. Thier engines were taken out of the Austin delivery trucks.