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240 Increasing power on a B20 Engine (Volvo Redblock)

edited January 30 in General
Hey recently bought myself a Volvo 240 Executive as a daily (Have a wagon getting modded), wondering on how I can improve the original engine for added power/torque? I've already done the following;
  • A lighter flywheel
  • Exhaust (Dual rather than a single)
  • 'Performance" intake and radiator - helps the car to breathe better/while trying to add power
  • New air filters

Anything else that can be done?


  • Pretty unlikely to be a b20 engine. What year model? The engines had a number of variations over the years so that changes to answer to your question a lot.
  • B20 in an OZ 240? That's unusual.

    240s in OZ up to 1978 model year all came with the B21 SOHC engine, the B20 was a pushrod non-crossflow 2 litre used in the 140s and earlier.

    240 engines in OZ went something like this -
    The B21 grew up to be the B23 and was fitted in the 242GTs at first, and then the regular 240s from year model 1981 onward to GL spec and above. AFAIK B23s for OZ market had K-Jet; B21s either had single carb or K-Jet.

    B23 changed to the B230 low friction engine with skinny rods and centre thrust bearing from 85 to 87, then went to the K block with rear thrust and bigger bearings in 88, then went from 9mm to 13mm rods in the K block at an indeterminate point during 88 model year , then the K block with 13mm rods in 1990, then the L block in 1991, then the L block with oil squiters for cylinder cooling, and round tooth timing belt in 1993.

    Volvo model years run from August to July, e.g. 1990 model year was made from August 1989 to July 1990.

    There are many different factory cams, which mostly interchange - slotted cams are only needed for 740 rear dizzy setups, but they'll all work okay in 240s with a block mounted dizzy.

    Then there' the turbo option. The pre-90 factory manifold works okay; the 90+ manifold works well but watch out for cracks; the eBay stuff doesn't work for long and is mostly crap.

    There are also many different SOHC head castings. These are identified by their casting numbers, found embossed on the head above #2 and #3 exhaust ports. e.g. Casting # 1000531 is called a '531' head. The 531 flows a bit better in stock form than the 530, but has slight lower compression. The 531 responds well to the usual stuff - e.g bigger valves, cc the chambers, 5 angle valve seat job, porting, etc.

    If you really want to flow, there is the 16V twin cam head, which will fit on the SOHC block, with a little help. In stock form, it flows as well as a mildly worked 531. A 16V into a 240 isn't for the faint of heart.

    What can be done depends on what you've got as a starting point.

    And how much you wanna spend.

    So.... wotcha got?
  • If it is a B20, fit a cross flow manifold and a Weber DCOE.
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