This bit is kinda embarresing
but many of you will find it quite funny, after stripping down the motor, removing the first 2 conrods and bearings and trying to turn the crank to remove the next 2. IT DIDNT TURN! after much swearing and stressing that we'd bent the crank. we tried almost everything we could think of my girlfriend walks out to the shed, peers down through the engine bay to me and says "should this belt still be on?"
Lo and behold we hadnt undone the air con pump belt and it was holding the motor solid as a rock. loosened it and it spun like a dream