Yes. There was a factory forged 86 mm crank used in the Volvo Penta marine engines. If you find one, make sure it has the same bearings as your motor. From about mid 87 on, the cranks are interchangeable. These motors used shorter pistons, but the same rods. If you stroke more, you may need custom pistons and/or custom rods. A few people in the US have stroked the older forged B21/23 cranks to 88-89 mm. I believe it is possible to go more, but I suspect you may run into clearance problems if you try to make a "square" motor. That would be expensive also, due to the other custom parts. I am not sure whether the cast crank used in the B230 is as good a candidate for stroking as the forged crank in the older motors.

Philip Bradley