Leyland-Thornycroft Diesels


New member
9 Jul 2001
Oxfordshire, UK
Thanks to all the advice recieved regarding earlier posting. I bought both sizes of BSP plugs 3/4" & 1", but the 3/4" only just dropped through the hole in the heat exchanger, and the 1" was a little bit too big. A local chandlery suggests it may be a NPT? American thread, any suggestions? The 3/4" plug threads were very close to those in the casting, are 7/8" or 13/16" or 15/16" BSP plugs available anywhere?

Note original post here July 9th:

I have recently bought a boat powered by 2off BLMC 2.2 Diesels. On one of the heat exchangers on the top of the engine (The long aluminium castings with the words Leyland-Thornycroft on them) the blanking off screw (approx. 25mm dia. is missing, unfortunately the plug in the other engine will just not budge for me to remove it to have a copy made. Has anyone got one or know where to find one from?

I am changing the mechanical gearboxes marked 'MOWOG' so if anyone needs one/a pair please email.