VOLVO ENGINE PICS & early Turbo information by Anthony Hyde


Looking closely at this 1983 European 760 B23ET Volvo Turbo display engine you might notice features not found on later USA (B23FT), or Australian (B23ET) 760/740 models.

Attached to manifold throttle body is a round cast 'air inlet hat' - this first featured on the non intercooled 1981-83 240 B21 ET/FT engines; Notice the intercooler with metal end tanks instead of plastic; A compressor relief valve vent-pipe located just after the intercooler that leads back to turbo compressor inlet; This early model featured Motronic L-Jet EFI.
Compression 9.0:1 (for leaded fuel) Power 170 hp(127 kw)@5,700 rpm, Torque 184 ft/lb(250 Nm)@3,400 rpm.

Manual gearbox in the picture is Volvo M45 for show purposes. Production turbo models used a beefed up M46 with 'D' Laycock overdrive.

B5254 all alloy engine, 1993 onwards - 5 cylinder, 10 or later 20 valve twin cam head,. Turbo version was B5234T

The first B21ET 1981 (non intercooler) Pic from Volvo manual New Car Features, 1981

B230FT Turbo (740/940)
4 cylinders, 2.3 litres, 8.7:1 comp

Beautiful B20 with Turbo+Weber = high hp

EARLY aftermarket 'TURBO KIT ' VOLVO ENGINES ~ 1976-1980
(GIK Turboteknik are aftermarket turbo specialists from Sweden - )

B21A with GIK Turbo Kit

B20 with GIK Turbo Kit

Cheap low boost turbo engine

OIL RETURN LINE on larger B21/B23/B230 'bell shaped' SUMP

If your considering converting a normally aspirated engine to turbo power, the engine block assembly from a B21A or B23A carburetor motor is a good choice as it already features lower compression pistons.
(The carby piston crown has a recess to give a lower static compression ratio - a B21E/F piston is flat and a B21 ET/FT has a 21cc recess).
Fuel injection is best, so try and source a K-Jet FI cylinder head with provision for mechanical injectors.
One essential addition is a turbo oil drain (turbocharger back to sump). For a B21/23 240 block, you can fit an
oil return line into the larger 'bell shaped' sump from say an 80-on model without removing the engine (only raising). If the engine is dissasembled, an option is to drill a large hole through the block and insert an oil return tube. Oil pressure to the turbo is obtained by fitting a tee fitting into the block sharing with the standard oil pressure switch. Source a B21ET/FT exhaust manifold and igntion distributor (boost retard feature) from a dismantler.

Return Line Sump Modification: Due to Volvo engine's approx 15 deg angle tilt, a turbo oil drain entry point 'into' the Volvo sump needs to be positioned as high up as possible to avoid having to pump through a sump fluid layer. After oil exits the turbo bearings it resembles a wipped froth and needs an unrestricted flow into the sump, otherwise there could be a pressure build-up & the turbo bearings will destroy themselves as new oil won't be pumped thru properly.

Position the hole where a B21/23ET/FT return pipe would drain in. Approximately half inch inside diameter pipe should be used, with attachment to steel sump by brazing or silver soldering as you can't weld all the way round with a stick. Use oil resistant rubber or silicon hose to connect up the turbocharger oil return line.

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