http://www.amazon.co.uk/Draper-71173-Flywheel-Locking-Vauxhall/dp/B00023T9LG

I needed something to lock my flywheel in place whilst undoing the pulley bolt and to keep it in the right place whilst doing the timing belt. There is a special tool listed/available but its over £30. Others have made their own (e.g. see Pauls K3). I was looking around the web and found the one linked here. Its meant for Vauxhall/Opel/Izuzu but at £1.36 delivered thought it was worth a try, even if it needed adapting. As it turns out it just needed a few strokes of a file to get one of the smaller gearbox bolts through the slot and the smaller end fits perfectly into the flywheel teeth and one of the threaded holes towards the bottom of the block when the timing marks are in the service position. Held it fine whilst undoing the pulley bolt that was very tight!