Sound of Merlin vs Packard.

[Al Schlageter]

Allison V-1710

Firing Order
RH turning: 1L-2R-5L-4R-3L-1R-6L-5R-2L-3R-4L-6R
LH turning: 1L-6R-5L-2R-3L-4R-6L-1R-2L-5R-4L-3R

Timing Ignition:
Intake fires 28° BTDC, Exhaust 34° BTDC, Sparkplug gap = 0.012-0.015"
Intake: Valve opens 48° BTDC, Closes 62° ABDC, 0.015" clearance (cold), 0.533" lift
Exhaust: Valve opens 76° BBDC, Closes 26° ATDC, 0.020" clearance (cold), 0.533" lift

V-1650-7

Firing Order 1A-6B-4A-3B-2A-5B-6A-1B-3A-4B-5A-2B

Spark timing Fully Advanced: Intake 45° btc, Exhaust 50° btc, Magneto breaker gap 0.011-0.014

Cam Timing
(crank degrees) Intake: Valve opens 31° BTDC, Closes 52° ABDC, 0.015" clearance (cold), 0.590" max lift -- Note: Time w/0.020
Exhaust: Valve opens 72° BBDC, Closes 12° ATDC, 0.020" clearance (cold), 0.590" max lift
263° intake duration, 264° exhaust duration
Note: Tappet clearance for timing -- 0.020"

The Griffon rotated opposite to the Merlin.

Larger capacity engines always produce a deeper growl.