How's my cam timing numbers?
 

Hello, I just finished timing my 1980 911 sc 3.0.
Stock cams, ideally is 155mm or in the range of
1.4-1.7. Prior to installing the hydraulic chain tensioner
I set the timing to 155mm on both cams tdc.
After installing my hydraulic tensioner.. must a
moved a little. It's final numbers are L cam 1.59mm
R cam 1.63mm. Are these good numbers? Am I in the
specs?
Thanks.

It’s all good...
Bruce

I would think that your engine might not be able to tell the difference between left and right. I would run with it.

Thanks gents.
Cheers.

The numbers are pretty flexible. I've set the cam timing on a race engine at the track by eye (no gauges available) just to get through the weekend and the lap times didn't suffer.
Most dynos wouldn't see the difference in those settings.

0.03mm = 0.001"

Using SAE/Imperial gauges which measure in inches, I'd have thought I'd died and gone to heaven if I got the two sides within one thousandth of an inch.

Porsche seems to believe that if you get both sides within the 0.4mm window, you are OK. Everyone thinks having both equal has to be the best, whichever end of the window you have chosen for your engine. But at some point you are just chasing your tail.

In your case, if you round the numbers up a decimal point you are spot on.

Thanks for all the input..it's my first Porsche
and my first engine tear down semi rebuild
( I didn't split the case). Learning a lot and just
Checking with the Pelican gurus more so often.
Cheers.

Henry,

There used to be a Porsche shop in Rainbow and I think they closed about a decade ago. I was replacing the right cam housing on my 76 and I wasn't sure about the numbers in the Haynes book. I called the shop and the guy was nice and gave me a number of .021 to .029 of lift. This was at least 15 years ago so I'm not 100% sure of the number but it was around .025 +/- a couple thou. I don't even remember which valve it was on, but it probably should be on the intake if its TDC of the exhaust stroke.

The pin that locates the cam chain tensioner had wallowed out its hole and was ready to fail and was making a death rattle. Fortunately I caught it in time before it let go. I bought a used housing from a dismantler in Burbank. They sent me a housing from a later model with oil fed tensioners so I filled the hole of the cover with some epoxy putty that comes in a roll.

The car ran fine after that. Did you know the guy at that shop and is his number correct for a 76 911S with a 2.7?

thanks