The Revolution Will Not Be Televised wrote:

On Tue, 5 Aug 2003 00:28:15 -0400, (Peter Stickney)
wrote:

snip

As you can see, at cruise, they're about even. While I wouldn't be
surprised it the Lanc II was a bit more draggy, and possibly heavier,
(Each Hercules weighed 500# more dry than the 20 series Merlin, but
that doesn't include the Merlin's radiators and coolant.)

I've seen comparisons that give about 250lbs extra per engine to the
Hercules version in early 1943, presumably when compared to the
fully-equipped Merlin versions, but this comes from a secondary source
(Holmes) and without context, and so it doesn't address the comparison
over time properly as the I/III auw was raised.

FWIW, Tubbs says that each of the Lanc Merlins had between 11 and 12.5 gallons, presumably
Imperial, of 70/30 water/glycol coolant. I have no idea what glycol weighs, so assuming
straight water you're talking ca. 100-125 pounds per engine of coolant.

Guy