In the first year of electronics training, we used to do field-training in
other fields within the department. I was lucky enough to get the
fire=tender engine overhaul unit. The 2 mechanics used to do a full reco of
the RR straight 8 petrol engines which powered the Thorney-Croft large
fire-tender,..14 tons full of water which was mixed with foammouta the
roof-mounted monitor. Apon completeion, they did consumption and power
measurements. Power was done by fitting the donk onto a bed then connected
to a huge alternator, which was connected to a series of heating elements
immersed in a huge water tank. You could connect and or disconnect elements
as needed. The donks exhaust manifold used to get a cherry glow when at
higher powers. All went well at low revs during the one I witnessed, then as
the throttle was opened the donk started running a little rough,..power was
down by about 20%. The mechy knew what was happening when he looked at the
inlet manifold vac-meter. It was jumping around. He opined that the valves
were sticking in their guides. He refitted the valves with more clearance in
their guides (another 2 days work), and the donk was sweeeet. I'll never
forget that fieldtraining. They also had one mechy who did all the carby
rebuilding in a closed off room to keep dust out. Then there was the little
Coventry-Climax for ancillary pump-work at aircraft accidents.     It was
DOHC,never got to see one running tho. Fuel consumption was charted on the
dyno, and it was here that the chief mechanical engineer could be a bit of a
PIA. He would not accept figures even slightly high, even by a smidgeon. The
normally quiet mechy who had to put up with the tut tutting of the engineer,
used to swear and mutter under his breath afterward.
I forget the size of the RR donk,..but it was big, maybe around 6 litres. No
fancy engineering, just a normal pushrod petrol motor.

Jason

It does.