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B230 Engine configuration: 2.32 Litre (2,320 cc), Bore 96mm Stroke 80 mm, 4 cylinder, cast iron block, alloy head with 8 valve overhead cam (belt driven), firing order 1-3-4-2.
The three engine types are normally aspirated, light pressure turbo & high pressure turbo.

B230 Engine YEAR	1985 - 1988.5 (B23 in 1984) The new low friction design	1989 - 1992	1993 Onwards (B230FB, B230FD)
Connecting Rods (Con-rods)	9 mm cross section. Marked 'H'	9 mm cross section <89,90 'M' 13 mm cross section >90 'H'	13 mm cross section. Marked 'M'
Pistons Turbo pistons are dished The B230FT OEM piston is "dishier" at 4.5 mm deep VS the B230ET at 3.6 mm deep therefore higher compression	short skirt	short skirt <90 full skirt >90	full skirt
Crankshaft Click to enlarge Shows a comparison between B21 & B230 cranks. Not shown is 85-88 low friction crank where thrust bearing is in centre, rather than end. (original pics SAM, Sweden) (Extensively reworked in Photoshop)	Small main bearing Ø 55.00 mm Ø 49.005 mm crank pins Thrust bearing location at #3 journal 8 counterweights, 80 mm stroke	Large main bearing Ø 63.00 mm Ø 49.005 mm crank pins Thrust bearing location at #5 journal same	same same same same
Block Expect any manner of surprises if the block is manufactured between 1989-92	Thrust bearing as above External clues - lens or disc type freeze plugs - no humps along the oil gallery on exhaust side	'K' cast into block late 88, 89 only (seen just below inlet manifold) Thrust bearing as above External clues - cup type freeze plugs - 3 distinctive humps above the oil gallery on exhaust side to accommodate oil squirters (the 4th is not so readily discernable) Oil feed thread in block for turbos is M14x1.5. Same for oil pressure switch.	same Additional external clue:- rounded tooth timing gear and belt
Block Identification	Casting date on exhaust side of block, behind the alloy engine mount bracket (remove bracket to gain access)	Casting date location same, but also need to check for letters cast into block (D, K, R, ?)	Casting date location same, but also need to check for letters cast into block (D, K, L, R) L? 94 oil squirters
Oil squirters for piston cooling	NO oil squirters or provision to install them	Telltale humps along the oil gallery on the exhaust side of the casting <90 may not be drilled	Telltale humps along the oil gallery on the exhaust side of the casting 93> drilled, tapped and blanked, or squirters installed if B230FT
Freeze or Welch plugs	lens or disc type	cup type ?	same
Cylinder heads	530	530 and 531	same
Oil / Mist separator	small	large	large
Timing belt / Pulley	Early engines have square teeth		(93+) have rounded tooth timing gear and belt
Camshaft	Slot at rear of camshaft to fit rear mounted distributor
Intermediate shaft	Gear for driving front mounted distributor may be a blank and not machined (All 240's have gear machined)
Fuel rail	- extra port if cold start injector is fitted - some have extra port for testing fuel pressure (Schroder valve)	Different years, slightly better versions	Different years, slightly better versions
Exhaust manifold The dual runners and general design is very good	early ones have oxygen sensor mounting drilled and tapped		Later turbo versions have tubular runners