964 pulley alignment

Rusty Brockmann · 07-22-2006, 08:02 PM

I recently replaced the distributor drive belt. In doing this I found the Z1 mark on the crank pulley points to TDC for #6 instead of #1. Can the crank pulley be installed more than one way? For instance could someone have mistakenly placed it on 120 degrees out, when replacing the V-belts?

axl911 · axl911's Garage

I don't think so. There is a dowel on the pulley that can only go in one place on the crank.

LeRoux Strydom · 07-25-2006, 01:14 AM

Are you sure you do not have cyls #1 and #6 confused? If you stand behind the car looking at the engine, #1 is on the left closest to you, #6 on the right furthest away from you.

Rusty Brockmann · 07-25-2006, 06:02 AM

Thanks, Gents, for your replies. I have triple checked this. I even checked mechanically, that #1 (left, rear cylinder) is TDC, when the dist. rotors are pointed to those spark wires. The car runs great, but Z1 is TDC for #6 (and of course its opposite.) I am trying to decide whether to leave well enough alone or to remove the pulley for repositioning.

krauthead · 07-26-2006, 03:36 AM

I could be thinking wrong here, but is it possible the spark plug wires have been rotated for some reason? I'm not sure if it is even possible on these cars but I know on older cars if you happend to put the distibutor in 180deg. off you could just move the spark plug wires and that would compensate. If the car is running perfectly I'm definitely of the "Don't fix it if it ain't broke" school.

MBEngineering · 07-28-2006, 09:58 AM

HI check your other posting.

regards mike

911TE · 08-08-2006, 02:32 AM

It is absolutely normal, because Nr.1 and Nr.6 have the same marking on the pulley.
If you turn the crank 360 degree (one full turn), the distributor as well as the cams do 180 degree (1/2 turn), so on the first full turn of the crank, Nr.1 fires, and at the next full turn with the same pulley position Nr.6 fires.

Sebastian

MBEngineering · 08-08-2006, 04:30 AM

HI have you lot in Germany been changing the crankshafts when we have not been looking, as all the engines i have worked on have No1 and No4 at TDC???(not No1 and No6???)that's No1 and No4 at the front of the engine and No3 and No6 at the back!!

regards mike

911TE · 08-08-2006, 05:25 AM

Hi Mike!

Sorry You are absolutely right, I mixed it up completely!

Thought Nr.1 and 6 are at the rear while it is Nr.1 and 4.
At least at the 993 pulley, there is only one way to mount the pulley and the three marks on the pulley have no designation as beeing Nr.1 or 6, there are just three notches 120 degrees apart.

964 may be different!