Cokey,
I have no idea why there are slots in the crank, be nice to find out though.
SteveN & R32 Combat
Since you know so much, who made the crank pulley that slackened off?
canadian,
On a high performance engine, crankpulleys need to be an interference fit on the crank, anything less and there may be issues with the bolt securing the damper slackening off.
OS Giken engines are often purchased by owners chasing big BHP which automatically introduces more crank flex and will test the security of the damper which I guess led to the statement issued by OS Giken. If the bolt slackens, it is the damper that is a fault as I know for sure the cranks are ground to size at tolerances better than .0005".
Just in case you missed it I gave my road going R34 ( as in full interior stereo etc, ) a spirited drive at TOTB V recently and produced a 10.49 second 157 MPH on the quarter and I have driven it every day to work since TOTB and just for the record, my crank pulley has never slackened off.
SteveN & R32 Combat, How many miles have you done in your cars recently, perhaps you have some fast times that you wish to share with us.
Get a grip guy's no one takes a pop at what you are up to with your engines, quite the reverse in my case. Not sure why you feel the need to take a pop, but two can play that game.