pinogg

I was wondering if someone could help me. I am trying to set the timing in my 993. I have an early production 993 so I have the old style sprocket with pin. I am trying to use the dial guage but my hydrolic lifters make it impossible. I tried using a hand modified lifter and that helps somewhat but how do I know I'm right on and what is 0 clearence. If someone could shed some light here I would greatly appreciate it.

chris walrod

First off, you need to replace that hydraulic insert with a solid, mechanical doo-dad of some kind to establish zero lash. Zero lash is important in setting valve timing..

If I may ask, what brought you resetting valve timing?

Howard

You could replace the rockers at 1 and 4 with the old style solid rockers. The rocker shaft is the same diameter so it will work. Then set the cam timing and replace the rockers.
The factory manual uses special tools to set cam timing on the 993. If you've changed the cams you'll have to do it manually with an indicator.

NineMeister

Zero lash means no clearance. In other words when you fit the solid 911/964 lifter to do the setting, screw the adjuster in until it touches the valve and then fractionally pre-load the valve with the screw so that it holds the valve just off the seat (like 5 thou'). Then set the dial gauge to zero on the retainer and carry on with the proceedure as normal.
Once you are done, back off the adjuster and replace the solid with the original hydraulic follower.