Valve Adjustment 1975 911s

MACHINEMON · 02-18-2005, 05:30 AM

CAN ANYONE HELP A NEWBE? 1975 911S. I HAD AN OIL LEAK FROM THE LOWER VALVE COVER SO, I GOT NEW GASKETS (ALREADY HAS 930 COVERS) AND WHILE I WAS AT IT I THOUGH I WOULD SET THE VALVES. I GOT THE .004 TOOL FROM PELICAN. THE PROBLEM IS THAT I DO NOT HAVE CONIFDENCE THAT I HAVE FOUND TDC. I THINK THE #1 EXHAUST ROCKER IS DRAGGING ALL THE WAY AROUND THE CAM BUT I AM SCARED TO LOOSEN IT. I DO NOT REGONIZE THE DISTR FROM THE PHOTO IN THE BOOK. I HAVE A PIC OF MINE IF ANYONE CAN TELL THE MANUFACTURER FOR ME. CAN THE VALVE BE SET ANYWHERE ALONG THE CYCLE AS LONG AS THE VALVE IS CLOSED? I FOUND AND HIGHLIGHTED THE Z1 AND 120 DEG MARKS ON THE PULLY. THANKS joeltriplett@hotmail.com

Superman · 02-18-2005, 07:39 AM

I'm not familiar with your distributor. In fact, I think it turns in the opposite direction of mine. Still, it should be fairly easy to determine when the rotor is approaching the contact point in the distributor cap that is connected to the #1 ignition wire. As the rotor approaches that, you should see timing marks coming up.

In theory, it should not matter whether you are exactly at TDC or not, since both valves should be about 180 degrees away from opening. As you look at the rockers and cam lobes, it should be obvious you are on the "heel" of the cam lobe. At this point, if the heel is putting any pressure on the valve train, then it is too tight. That is, if there is no clearance when the heel of the cam lobe is facing the rocker arm pad, then that valve is staying open, or nearly so. Bad.

It does not need a lot of clearance. Newbies typically leave them too loose. So, you're looking for a bit of drag on the feeler gauge. Also, you should have replacement tabs ready. I have torn plenty of those things. And finally, putting loctite on the tiny bolts and nuts that hold the feeler gauge tab to the holding tool is a good idea. If you don't, you're likely to eventually loose a nut that falls off the tool an into your engine.

island911 · 02-18-2005, 08:23 AM

Some great advice from Superman, there.
If the rocker-arm is off the cam-lobe you are fine adjusting the gap.

MACHINEMON · 02-21-2005, 04:58 AM

THANKS, THAT WAS SOME GOOD ADVICE. I WANT THOSE VALVES ADJUSTED CORRECTLY! DID ANYONE KNOW WHAT MAKE THAT DISTRIBUTER IS? I BOUGHT THE CAR SIGHT UNSEEN BECAUSE OF THE PRICE AND THE VERY FEW BITS OF INFO I GOT SO I DO NOT KNOW WHO BUILT THE MOTOR. IT IS A 7R CASE, 930 VALVE COVERS, NEW OIL COOLER AND SEEMS TO BE BRAND NEW CLEAN ON AN 85K MILE CAR. THANKS AGAIN EVERYONE.....JOEL