It's been more than a year that OPS has finally changed the crankcase to a more modern Novarossish layout. Actually I think it comes from the Vega family engines. I'm pretty sure they gave up square stroke for long stroke. Much better engine now.
Still the preistorical OPS family were, in my opinion, very nice to drive, due to the typical OPS power range, short and full of torque. In my Pan Car it was funny to drive! A step behind the usual fast engines, though.