Around 1995 Porsche changed the method of affixing the cam drive gears to the cam(as best I can determine). Apparantly early cars used a woodruff key and later cars used a 'vernier system' of some sort. I am familier w/ the older system but have no idea about the newer system, other than that the cam gears need to be changed on the newer cars when a performance cam is installed. Can anyone explain? Any pictures?

 

Bill;

The early style method is prefered, (my opinion) There have been cases of the sprocket rotating by mistake. When using a performance cam the earlier style sprocket with pin is probably enforced or recommended. The manuals show and explain the difference in detail.

 

[quote]Originally posted by Bill Verburg:
<strong>Around 1995 Porsche changed the method of affixing the cam drive gears to the cam(as best I can determine). Apparantly early cars used a woodruff key and later cars used a 'vernier system' of some sort. I am familier w/ the older system but have no idea about the newer system, other than that the cam gears need to be changed on the newer cars when a performance cam is installed. Can anyone explain? Any pictures?</strong><hr></blockquote>

Hi Bill:

Kevin is right on the money.

This newer method of attaching the cam sprockets to the cams and setting timing is inferior to the older hardware, and this accounts for the variations in power outputs in the 993 3.6 litre engines.

Its very difficult to set the cam timing accurately side-to-side and to the spec you want
so we backdate all of the 993 engines that we open up for overhaul or upgrades.

 

Thanks guys! Is there a retro fit kit(I see that FVD has what appears to be the kit but there is little info available on their website)? I spoke briefly w/ the folks at WebCam the said that they ony sell the cams, not the drive gears?

 

[quote]Originally posted by Bill Verburg:
<strong>Thanks guys! Is there a retro fit kit(I see that FVD has what appears to be the kit but there is little info available on their website)? I spoke briefly w/ the folks at WebCam the said that they ony sell the cams, not the drive gears?</strong><hr></blockquote>

Hi Bill:

Your friendly neighborhood Porsche Dealer can get you exactly what you need.

You will need earlier (964) cam sprockets, inner flanges, timing pins and locking nuts.

 

Thanks again Steve! Sounds like a good use for the PCNA rebate.