[edwest2]

From another website, so unverified but with good references:




Almost any engine could use 150 octane, but not all could run at the
higher boost pressures to get any benefit.

A Bristol document, AVIA 8/434 and AVIA 15/2922, gives the following:

Centaurus 7.5 - 8.5 lbs boost, no change with 150 octane (the
Centaurus was later increased to 10 lbs boost with water injection, 12
lbs with 150 octane, and possibly 16 lbs with water and 150 octane
(don't know if this last one was approved, although I've seen the
power chart for it)

Hercules: no change with 150 octane

Sabre: no change at 11 lbs (although they later increased to 13lbs,
iirc)

Merlin 63, 64, 72, 73 18lbs with 100, 21 lbs with 150

Merlin 66, 70, 71, 76, 77, 266, V-1650-7, 100, 101, 130, 131, 113, 114
18lbs with 100, 25lbs with 150 (there is a note about changing
ignition timing with Merlin 66)

Griffon 61, 65, 66 18lbs with 100, 21lbs with 150.

Griffon 64, 67, 85 18lbs with 100, 25lbs with 150

There are minor increases with some Pratt & Whitneys, the Packards and
Wrights listed all remain the same. Note however that these may have
changed later, certainly some of the British engines did.