Check, setting and adjusting cam timing
 

It's not normal maintenance (I think, because I can't find it in the maintenance schedule). If it is indeed not normal maintenance, how do you know it's time to do this?

My car has about 75k mls on it and runs good. If there is already a topic on the forum would you please paste the link for me. Thanks in front.

This is not maintenance, you would need to drop the motor down, but before that you would need cam tools, chain housing gaskets a dial indicator and know how.

I know. Can also be done in the car, see PP 101 projects. But how do you know it is time?

However, the cam timing can be changed and altered with the engine in the car. Quite a few things need to be removed or placed out of the way: engine mounts, A/C compressor, spark plugs, valve covers, some heater hoses, fuel injection components: but it is indeed possible.

Pelican Technical Article: Setting and Adjusting the Cam Timing - 911 (1965-89) - 930 Turbo (1975-89)

properly set, it really doesn't change more than a 1/10mm in 100K miles. the spec range is more than that.

Once the cam timing is set it doesn't change unless the tensioners fail or the chains stretch beyond their limits.

You don't normally check this. If you wanted to make sure someone hadn't screwed with it before, or you wanted to change it to another value, for one reason or another, then you could do it. It's not part of the routine maintenance, ever, really.

JR

I have done this three times testing different timing, unless you drop the rear of the motor down, it is no fun, and I don't mean pull the motor and tranny.

OK, thanks to you all. I know nobody messed with my car, it is only maintained and runs very good. So back to normal maintenance schedule.

Another question. When are the chains stretched beyond there limits? How many miles do they approximately last?

no way to tell. It depends on abuse like hard driving and lack of oil changes but maybe 140,000 miles or so.

Is this procedure same in all 911s up to 89 ?

I am doing that on a 1985 3,2 right now and i am looking to verify the setting marks

Please someone confirm

we are assembling a 3,2 Carrera engine that we got stripped

The basic procedure is the same but the details can vary. You'll need the timing specs for that era. There's a bunch of different values, for the different engine versions made over the years.

JR

Some of these settings depends on cams, when I went with Solex the company that did the grind included cam timing.