4.0 Inline 6 cylinder DOHC VCT 24-valve
BA – 2002 to mid 2005 Falcon, Fairmont, Fairlane and SX Territory. Rated at 244 hp/280 lb-ft, compression ratio of 9.7:1. Standard design motor with what is said to have the weakest connecting rods of all variations. Front-sump oil pan.
BF – late 2005 to early 2008 Falcon and SY Territory. Rated at 255 hp/282 lb-ft, compression ratio of 10.3:1. Has slight revision to camshaft profiles, dual VCT, secondary knock sensor and upgraded ECU. Models after 06/06 are said to have same connecting rods used in turbo model engines. Front-sump oil pan.
FG – 2008 to 2014 Falcon and SZ Territory. Rated at 261 hp/288 lb-ft, compression ratio of 10.3:1. Has plastic intake manifold and redisigned cylinder head. Rear sump oil pan.
E-Gas – Propane/LPG only model engine, does not have standard petrol/gasoline fuel injectors, rails or wiring. Rated at 209 hp/276 lb-ft, compression ratio of 10.3:1 for BA model, 10.7:1 for BF/FG. BA/BF have green valve cover and are said to have same connecting rods as used in turbo model engines, but with a press-fit wrist pins.
Turbo – Factory turbo engine, available from all models and years with slight variations throughout. Rated from 322hp/332lb-ft to 436hp/425lb-ft, compression ratio of 8.5:1 to 8.8:1. These models came with a red valve cover, except for the FPV model which came equipped with a blue cover. Stronger connecting rods were introduced in May, 2006 and changes were made throughout the years to increase power output in factory form.
Please visit https://en.wikipedia.org/wiki/Ford_Barra_engine for even more detailed information.