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Registered
Join Date: Jul 2005
Location: Yorkshire UK
Posts: 1,097
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Help With 3.2 Z1 Mark
Im just about to start my cam timing on my 89 3.2 but im having difficulty deciding which mark is Z1 on my pulley. In the book it shows a series of 3 marks with the right most mark been Z1, My pulley has no id on any of the marks there is a series of 3 marks close together like in the book on my pulley but at these marks pistons 1 and 4 are not at the tops of there strokes. If I rotate my engine and estimate TDC on cylinder 1 and 4 by looking through the spark plug holes the case parting line lines up with a mark on its own on the pulley is this likely to be Z1?
Thanks Steve |
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Registered
Join Date: May 2003
Posts: 3,346
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Steve,
I don't have the info in front of me so this is from memory. Most pulleys have marks every 120 degrees for TDC on 1/4, 2/5, and 3/6. They also have marks for 30 to 35 degrees of advace. Some have other marks about 5 degrees from Z1. To find the Z1 mark I'd look for the 3 marks that are 120 degrees apart (3 equal spaces around the pulley). The one that is closest to the 30-35 degree pair and at exactly 120 degrees from the other 2 marks is Z1. If it has a mark next to it, that one will be for idle/static timing of the ignition. -Andy
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72 Carrera RS replica, Spec 911 racer |
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Irrationally exuberant
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There a 4 marks on the 3.2 pulley, 2 of them are close to each other. Of those two, the left one is the TDC mark. I think of the right one as a "look out, TDC is approaching" mark.
-Chris
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'80 911 Nogaro blue Phoenix! '07 BMW 328i 245K miles! http://members.rennlist.org/messinwith911s/ |
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Join Date: Jun 2004
Location: Rio Rancho, New Mexico
Posts: 1,325
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Here is a picture of my '85 Carrera 3.2 at TDC #1 (Z1). Notice the mark about one inch to the right. That is the full advance ignition mark, abt. 35 degrees. The second picture shows the rotor position at #1 TDC (Z1). If the rotor is pointing down when at Z1, then you are at #4 TDC. The other two marks are down and out of the picture 120 degrees away. As the motor runs the marks are moving left to right (clockwise).
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DOUG '76 911S 2.7, webers, solex cams, JE pistons, '74 exhaust, 23 & 28 torsion bars, 930 calipers & rotors, Hoosiers on 8's & 9's. '85 911 Carrera, stock, just painted, Orient Red Last edited by 2.7RACER; 11-13-2005 at 09:22 PM.. |
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Registered
Join Date: Jun 2004
Location: Rio Rancho, New Mexico
Posts: 1,325
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Here is the second image referring to the rotor position.
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DOUG '76 911S 2.7, webers, solex cams, JE pistons, '74 exhaust, 23 & 28 torsion bars, 930 calipers & rotors, Hoosiers on 8's & 9's. '85 911 Carrera, stock, just painted, Orient Red |
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MBruns for President
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I put a blue arrow on mine to help - just a cut piece of tape...
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Current Whip: - 2003 996 Twin Turbo - 39K miles - Lapis Blue/Grey Past: 1974 IROC (3.6) , 1987 Cabriolet (3.4) , 1990 C2 Targa, 1989 S2 |
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Registered
Join Date: Jul 2005
Location: Yorkshire UK
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Ok thanks guys I think Ive got it now there is three marks at 120 degrees apart and the one that is lined up with the case line when piston 1 and 4 are at the top has a mark about 35 degrees infront of it (im presuming the full timing advance mark) so this must be the Z1 mark.
Steve |
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