On Jul 24, 7:29 pm, "Percival P. Cassidy" wrote:
Richard W. wrote:
Thre are two sorts of heating oil. 25 sec and 35sec. (That's how we
measure the viscosity in the UK.) 25sec (kerosine) is for
vapourising burners. [Basically a big wick]
35 sec (= to diesel) for pressure jet burners.
25 sec can be burnt in a petrol engine. However the engine needs to
be hot before it will run. In days of yore some agricultural tractors
ran on this (known as Tractor Vapourising Oil). They had two tanks,
you started the tractor on petrol & then switch over to the kerosine /
TVO Smelly exhaust.
I have seen some of those tractors, but the more common one is the
International which is started on gas and switched over to diesel when it
got warm. Some of those engines are fairly large.

My late father had an International TD9 that started on gasoline and
then changed over to diesel, but my understanding is that it was simply
because hand-cranking a diesel engine like that was impractical, not
because it needed to warm up. The compression ratio was much lower when
it was in gasoline mode, and cranking was far easier.

Perce

It was Massey Ferguson over here. A very small tractor. Harry
Ferguson invented the three point linkage. With it, this tiny
tractor could do the work of a much bigger tractor of the tiime. Only
the early ones had it (around sixty years ago)
Later ones had a diesel engine.
There are still lots about working on farms. TVO is no longer
available so they use heating oil now.
Don't see how you can change the commpression ratio of an engine
(except model aero engines) The engine had to be hot, the TVO needed
the hot spot to vapourise it. (pre crossflow technology)
Many early diesel engines could be hand cranked, they had a valve
lifter, a little lever on the crank case (side valves) It held the
exhaust valve open, you cranked like hell & then dropped the valves
and it started (hopefully) They had big flywheels in those days,
stored lots of energy.