How do you remove the cam sprocket bolts on a 993?

[earossi]

I've posted this item on the engine rebuilding forum but have not received any usable suggestions.

I am doing a head job on my 993 3.6 motor. As you may know, Porsche has changed the design of the sprockets for the 993 and they are no longer pinned to the camshaft using a two sprocket system for cam timing. Instead, the timing chain sprockets are held in place on the camshafts only through the use of friction created between the cam bolt and the sprocket against the face of the camshaft. To assure that this attachment does not slip, the cam bolt is torqued down with quite a bit of torque. To break the bolt loose requires the use of special tools that lock the camshaft to the cam carrier allowing you to break the bolt loose. Unfortunately, the tools to lock the cams in place are about $300, which is not good.

The 993 sprockets do have (4) equally spaced holes around the sprocket face, which are presumably there to accept a pin wrench to hold the sprocket while installing or breaking the bolt loose. Unfortunately, I have not been able to locate the proper wrench to use with the hole configuration.

I know that others have had to address this issue when removing their camshafts; and, I am hoping there is a work around to buying the expensive locks.

Comments and suggestions would greatly be appreciated.