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-   -   TDC alignment for valve adjustment? (http://forums.pelicanparts.com/porsche-911-technical-forum/591211-tdc-alignment-valve-adjustment.html)

Gustyones 02-12-2011 05:15 AM

TDC alignment for valve adjustment?
 
I am diving into my first valve adjustment and as I rotate the crankshaft pulley to the point where the two marks are the closest and arrive at the 1st mark, the distributor a few degrees past the 'notch', as I arrive at the 2nd mark, the distributor is obviously about 5 degrees further past the 'notch. I can't see the Z1 mark on my pulley. Any direction would be much appreciated :confused:

Gustyones 02-12-2011 06:01 AM

OK, I have a slight update. I think I determined that the left most mark is TDC, however at that point I can't move the valves on cyl#1, but #4 moves. If I turn the engine again so the distributor is exactly 180 degrees, the valves on cyl #1 move. Could my distributor be off 180 degrees?

pete3799 02-12-2011 06:02 AM

Turning clockwise the first notch should be 5* before TDC the next should be TDC.

Drisump 02-12-2011 06:04 AM

There are many threads on the topic if you get bogged down. Your Z1 line should be there along with the subsequent 120 degree marks. Have you tried to locate any of the three on the pulley? I assume that the valve covers are off and the oil drained. When the rotor is pointed at the notch, are the rockers for #1 loose? If they are, and you can't see any marks on the pulley, you may have to make your own marks. Easiest way might be to measure the diameter of the pulley, multiply by 3.14 and cut a piece of masking tape that is that long. Make marks dividing the total length into three and attach to the pulley (the lip to the rear of the car....the seam being at the center of the engine case (Z1). You can now center punch through the tape for a permanent solution. Good luck,do you have Waynes book?....You should consider it, if you don't.

Drisump 02-12-2011 06:06 AM

Quote:

Originally Posted by Gustyones (Post 5842339)
OK, I have a slight update. I think I determined that the left most mark is TDC, however at that point I can't move the valves on cyl#1, but #4 moves. If I turn the engine again so the distributor is exactly 180 degrees, the valves on cyl #1 move. Could my distributor be off 180 degrees?

Yes and seems to be a fairly common problem. Sorry, I was writing reply as you were sending more info,
cheers.

pete3799 02-12-2011 06:15 AM

With the dist. cap in place the plug wire to the right of the front clip that holds the cap on should be going to cyl.#1. Is it?

steve911T 02-12-2011 06:44 AM

Pete is right, you are 180 Degrees off, need to make sure the rotor in the distributor is under #1 plug wire. Steve

Gustyones 02-12-2011 06:52 AM

Thanks Steve and Pete. It appears the rotor us just a little to the left (counter clockwise) of the #1 plug wire.

Walter_Middie 02-12-2011 07:00 AM

Quote:

Could my distributor be off 180 degrees?
Your measurement is 180 deg out - not the distributor. Do not remove and replace the distributor after turning it 180 deg.

The engine will point at TDC twice - once while the distributor is firing #1 and once while firing #4. You just need to keep turning the engine until you get to TDC with the valves for #1 loose and the engine is pointing to TDC. At this point, the distributor rotor should be pointing to the position where plug wire #1 attaches. You don't have to be exactly at TDC - just close.

Drisump 02-12-2011 07:35 AM

Quote:

Originally Posted by Walter_Middie (Post 5842427)
Your measurement is 180 deg out - not the distributor. Do not remove and replace the distributor after turning it 180 deg.

The engine will point at TDC twice - once while the distributor is firing #1 and once while firing #4. You just need to keep turning the engine until you get to TDC with the valves for #1 loose and the engine is pointing to TDC. At this point, the distributor rotor should be pointing to the position where plug wire #1 attaches. You don't have to be exactly at TDC - just close.

Walter is correct, but you should still have three visible marks on the pulley.ie Z1 should come around twice, once for 1 and once for 4.

Drisump 02-13-2011 05:57 AM

Sorry Gustyones, I shouldn't post with the lack of sleep I'd had for the last few days. I see now ( that I am half rested) that you had located the marks on the pulley and that everything was as it should be....you simply had to rotate the crank once more revolution. Hopefully you figured this out with the info posted by walter and the past threads. Cheers

Joe Bob 02-13-2011 06:07 AM

Neat video that helps.

Porsche Valve Adjusting Screwdriver

Gustyones 02-13-2011 07:21 AM

All, Thanks so much for your help. This forum is awesome!!!!! That video is great Job Bob.

I was able to locate TDC with your help and got through the valve adjustment. It will be so much easier next time. I started to get the 'feel' for it by cylinder# and the process sped up.

Unfortunately, somehow during the process I broke my ignition rotor and have to order another one. I'll need to wait 'till it arrives to start the car and see how I did. :(

rusnak 02-13-2011 07:52 AM

The car wouldn't run if the dist. Was off 180 deg. I'm sure know this now.


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