For WW2 engines I think so. I can't recall any other H form engines operating in the war, though that doesn't maen there weren't any.
The Sabre had the highest output per cubic inch of capacity of any engine of WW2, suppassing 1 hp per cubic inch in 1940 and eventually getting up to 1.35 hp per inch cubic capacity in 1942 and 1.79 hp per cubic inch by the end of the war (that is over 4000 hp from a 36.7 liter (2238 cc) engine). Service engines such as a Sabre IIb would produce about 1.07hp/ cubic inch, but more in emergency situations. Closterman describes overboosting his Tempest V to 3000 hp and 13lbs boost, but this was apparently non standard and could only be done on the Sabre IIc, which had a stronger chankshaft and was tested but not officially cleared for 13lbs boost.
Closterman quote:
""
Thanks to its 2,400 h.p. engine it had a considerable margin of excess power and its acceleration was phenomenal. It was pretty tricky to fly, but its Performance more than made up for it: at 3,000 feet, at economical cruising speed on one third power (950 h.p.) with two 45-gallon auxiliary tanks, 310 m.p.h. on the clock, i.e. a true air speed of 320 m.p.h.; at fast cruising speed, at half power (1,425 h.p.) without auxiliary tanks, 350 m.p.h. on the clock, i.e. a true air speed of nearly 400 m.p.h.; maximum speed straight and level with +13 boost and 3,850 revs.: 430 m.p.h. on the clock, i.e. a true air speed of 440 m.p.h.
In emergencies you could over-boost it up to nearly 3,000 h.p. and 4,000 revs., and the speed went up to 460 m.p.h. In a dive the Tempest was the only aircraft to reach, without interfering with its handling qualities to any marked extent, sub-sonic speeds, i.e. 550-600 m.p.h. ""
I had a look and couldnt find anything anyway...does anyone else have any information on the two engines and how they compared?
