ReferenceB58

B58 spec sheet: every factory number on one page

The B58 factory data on one page: compression, oil capacities by revision and drivetrain, piston and ring tolerances, crank clearances, head-bolt grades, torque rows — every carried row factory-cited.

8 min readUpdated 2026-10-21Rapid Racing

The B58's data lives in different shelves than the N54's: instead of one classic technical-data document per subsystem, the G-era factory layer spreads the numbers across overview documents with per-revision validity blocks and multi-validity procedure documents. This page pulls every B58 row that layer carries onto one sheet — identity, clearances, capacities, fasteners — with the same citation law as the N54 spec sheet, and the same honesty about the rows that are not carried.

Engine identity — what the overview data carries

Parameter	Value	Validity
Compression pressure	> 12 bar	M output class, revision 0
Max. uninterrupted starter operating period	15 s	B-engine family overview
Minimum starter cooling-down period	carried for N63/S63 (10 s run / 20 s pause); no separate B58 row	overview data

Factory service documentB58 engine in general — compression pressure and oil capacities by revisionOpens in your account's service knowledge — sign-in required.

The honest gaps, stated up front: the overview documents we hold do not carry the B58's bore, stroke, displacement, or compression ratio — the identity block the classic N54 documents carry is simply not in this layer of the extract, and we do not quote numbers we cannot cite. The same applies to power and torque ratings: service data, not sales data. What the extract does carry — in full, per revision — is below.

The revision split — the B58's own TU law

The overview data keys its B58 rows to MOTUeberarbeitung — the revision digit. Reading it honestly:

Revision	Roughly	What changed (carried in the functional descriptions)
Revision 0	2015–2018 (G11/G12 740i/540i era through G20 launch)	The original two-chain drive
Revision 1 (B58TU)	2018+ (M340i, Z4 M40i, X3 M40i, G20 340i era)	One-piece chain drive redesign — the functional description documents the change
Revision 2	G70 era	Later output states

Factory service documentB58TU functional description — the one-piece chain drive redesignOpens in your account's service knowledge — sign-in required.

The chain-drive redesign is why so many B58 torque rows carry two answers: the pre-TU engine and the TU engine are different fastener populations, and a spec sheet that blends them is worse than none. Every table below states its revision scope.

Pistons and rings — 1125 overview data

Measurement	Value	Validity
Piston Ø, measuring point 14 mm from skirt end	81.953–81.971 mm	revision 0
Piston Ø, measuring point 10 mm from skirt end	81.958–81.996 mm	revision 1 (B-family row incl. B58TU)
Upper compression ring side clearance	0.035–0.085 mm	revision 0
Centre compression ring side clearance	0.015–0.06 mm	revision 0
Upper compression ring end clearance	0.20–0.28 mm	revision 0
Centre compression ring end clearance	0.20–0.28 mm	revision 0

Factory service documentB58 pistons and rings — diameters and clearances by revisionOpens in your account's service knowledge — sign-in required.

Note the measuring-point move between revisions — 14 mm to 10 mm from the skirt end — which is why the two diameter rows are not comparable to each other, only to their own revision's bore. The pistons-and-rings-install guide owns gap clocking and the file-fit honesty.

Crankshaft — 1121 overview data

Measurement	Value	Validity
Axial clearance of crankshaft	0.090–0.314 mm	revision 0
Maximum permitted turning torque of crankshaft (bolted, no rods/pistons check)	2 Nm	B58 (both revisions carried in the family row)

Factory service documentB58 crankshaft — axial clearance and maximum turning torqueOpens in your account's service knowledge — sign-in required.

The 2 Nm turning-torque ceiling is an assembly-truth check: a crank that will not turn by hand within it has a bearing or thrust problem, not a "needs to break in" problem. The rod-and-main-bearings guide owns the shell classification tables the B58TU data carries — the letter-pair shell selection system is a table set of its own.

Bearings — the B58TU classification tables

The revision-1 engine carries a shell classification system in its own documents: main bearing shells 1, 2, 3, 5, 6 as one table, main bearing shell 7 as another, guide bearing shells 4 as a third. The tables pair block-bore letters to crankshaft-journal letters and select the shell — the same selection philosophy as the N54's color grades, executed with different furniture. The full tables live in the rod-and-main-bearings guide; this sheet carries the pointer, not a transcription, because the selection is meaningless without the guide's measurement sequence.

Oiling — capacities by revision and drivetrain

Quantity	Value	Validity
Oil change with filter element	6.5 litres	revision 0
Oil change with filter element, rear-wheel drive	6.5 litres	revision 1, M and O output
Oil change with filter element, all-wheel drive	7.0 litres (M output) / 7.2 litres (O output)	revision 1
Oil change with filter element	6.75 litres	revision 2 (G70)
Oil drain plug / drain screw	per the drain-and-add procedure; new sealing element	all
Oil filter cap	25 Nm	carried in the G11 procedure set

Factory service documentB58 — drain and add engine oil: procedure, level check, disposalOpens in your account's service knowledge — sign-in required.

The xDrive rows are the ones people get wrong: the same engine carries half a litre more oil in an xDrive sump than in a rear-drive one, and the level sensor will not forgive optimism in either direction. The engine-oil-change-guide owns the LL-01 honesty; the overfill warning in the B58 procedures is the same drumbeat as the N54's — engine damage caused by overfilling is written as a risk callout, not a suggestion.

Cooling — the B58's heat-management shape

The B58 cooling system is a managed circuit, not a thermostat-and-prayer arrangement: the functional description documents the heat-management module — multiple map-controlled consumers (coolant pump, split cooling, heater circuit) orchestrated by the engine control unit. What that means for service: the bleed procedure is not optional ritual, and the factory writes it around a special filling/bleed tool. The coolant-service-and-bleeding-guide owns the bleed law and the tool; the water-pump-and-thermostat-guide owns the electric-pump failure pattern.

Factory service documentCooling system bleed with the special tool — the B58 family procedureOpens in your account's service knowledge — sign-in required.

Per the factory data we hold: the coolant volume by chassis is not carried in the B58's overview layer the way the classic N54 documents carry it — the fill procedures reference the operating-fluids specification for quantity and grade routing, and that layer is not in our extract. The fluids-and-capacities-bible keeps that split honestly.

Ignition — plugs and coils

Fastener	Thread	Torque
Spark plug, dry thread	`M12x1.25`	23 ± 3 Nm
Ignition coil to cylinder head cover	`M6`	8 Nm

Factory service documentSpark plugs torque table — M12x1.25 at 23 ± 3 Nm, dryOpens in your account's service knowledge — sign-in required.

Same table as the N54's — the all-engines row covers both — and the same honesty: no plug gap is carried in the torque layer, because the gap lives in the plug specification, which our extract does not carry. The spark-plug-and-coil-guide owns the B58's one-step-colder and misfire-triage context.

The fastener spine — torque-plus-angle table

Fastener	Thread	Torque	Validity / owner
Vibration damper to crankshaft	`M10x65` ×4	40 Nm + 120°, renew screws	all revisions — b58-crankhub-and-timing-guide
Cylinder head bolt, grade 13.9 (13 mm head height)	`M11x1.5x188`	30 Nm + 50 Nm + 90° + 90° + 90° + 90°, renew	head-gasket-and-tty-bolts
Cylinder head bolt, grade 11.9 (11 mm head height)	`M11x1.5x188`	30 Nm + 90° + 90° + 90°, renew	head-gasket-and-tty-bolts
Head bolt to timing case cover	`M8x40`	19 Nm, renew	head-gasket-and-tty-bolts
Connecting rod bolts	`M9`	20 Nm + 70° + 70°, replace, oil	rod-and-main-bearings
Chain tensioner to cylinder head (G11 procedure set)	`M22x1.5`	20 Nm + 30°, new sealing sleeve	valvetrain-and-timing-refresh
Chain tensioner (G20 procedure set)	`M22x1.5`	20 Nm + 40°, new sealing sleeve	b58-crankhub-and-timing-guide
Camshaft sprocket to crankcase	—	108 Nm, clean thread	b58-crankhub-and-timing-guide
Bearing journal, tensioning/guide rails	—	20 Nm, replace journal	b58-crankhub-and-timing-guide
Bottom chain tensioner to crankcase	`M6x22`	9 Nm, clean thread	b58-crankhub-and-timing-guide
Rear timing case cover to crankcase	`M6x31`	8 Nm + 90°, renew screws	b58-crankhub-and-timing-guide
Oil pump to crankcase (external Torx)	`M8x35`	19 Nm	b58-crankhub-and-timing-guide
Oil vacuum pump to crankcase	`M8`	15 Nm + 45°, renew	b58-crankhub-and-timing-guide
VANOS central valve to camshaft	`M20x1.5`	10 → 30 → 50 Nm + 35°, staged	b58-crankhub-and-timing-guide
VANOS gear to intake/exhaust camshafts	`M10x1`	30 Nm + 90°, renew central bolt	b58-crankhub-and-timing-guide
Cylinder head cover to head	`M6`	8 Nm then 11 Nm, two-stage, sequence per guide	valve-cover-and-gasket-guide

The two chain-tensioner rows are not a contradiction — the G11-era procedure set and the G20-era procedure set each carry their own number for their own engine population, and both are quoted with their scope. When in doubt, the guide for your chassis owns the answer.

Walnut blasting and the head — carried service parameters

Parameter	Value
Blast duration, walnut granules (per port)	approx. 20 s
Blow-out duration, compressed air	approx. 10 s
Operating pressure	6–8 bar
Head watertightness test temperature	60 °C
Head watertightness test pressure	3.0 bar max

Factory service documentB58 family — intake-port cleaning parameters and head watertightness limitsOpens in your account's service knowledge — sign-in required.

The direct-injection carbon conversation is the same on the B58 as the N54 — the walnut-blasting-guide owns the craft — and the head-watertightness numbers are the pressure-test ceiling for any B58 head off the car: the same 3 bar law the N54's block-off testing carries, one engine generation later. The head-block-off-and-pressure-testing guide owns the rig.

What this sheet does not carry — the honest verdict

Bore, stroke, displacement, compression ratio, valve dimensions, cam runout, oil-pressure floors, coolant volumes: none of these rows are carried in the B58 layer of our factory extract. Where the N54's classic documents carry them, the B58's overview documents stop at what the tables above show. Where the community publishes those numbers, they are community numbers — this sheet stays factory-cited, and the b58-buyers-guide handles the ownership conversation with the community evidence labeled as community.

Factory sources

Questions

How much oil does a B58 take?

6.5 litres with the filter on the pre-update B58 (revision 0) and on rear-wheel-drive revision-1 cars. Revision 1 all-wheel-drive sumps carry more: 7.0 litres on M-output and 7.2 litres on O-output variants, per the factory overview data. The G70-era revision 2 carries 6.75 litres.

What is the B58 compression pressure spec?

Greater than 12 bar, carried in the factory overview data for the M output class of the pre-update engine. The overview carries no separate per-cylinder deviation row for the B58 the way the classic N54 data does.

What are the B58 head bolt torques?

Split by screw-head height: grade 13.9 bolts (13 mm head) are 30 Nm + 50 Nm + 90° + 90° + 90° + 90°; grade 11.9 bolts (11 mm head) are 30 Nm + 90° + 90° + 90°. All are torque-to-yield and replaced every time. The M8x40 bolts to the timing case cover are 19 Nm.

What is the B58 crankhub bolt torque?

There is no central hub bolt like the N54's. The B58 vibration damper bolts to the crankshaft with four M10x65 screws at 40 Nm + 120°, renewed every time.