 Question for Six Engine People, TDC and Z1 mark |
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| Robarabian |
 Mar 15 2023, 08:48 PM
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#1
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914 A Roo  Group: Members Posts: 687 Joined: 11-February 19 From: Simi Valley, Kalifornia Member No.: 22,865 Region Association: Southern California 
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I have a 911 engine I am working on. I am practicing setting cam timing so I can feel comfortable with it prior to the tear down. My Crankshaft pulley has a Z1 mark that has 2 lines. So I have seen 911 pulleys with Z1 and 1 line.
The question de jour is which of the 2 lines at Z1 is TDC? Or are the 2 lines giving me the dwell of where TDC is and if so, where should I put them in relation to the case to set cam timing and do valve adjustments. it looks like " Z | | 1" It is a 2.4 Somebody knows this answer. |
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| targa72e |
Mar 15 2023, 10:33 PM
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#2
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Member Group: Members Posts: 287 Joined: 11-September 16 From: colorado Member No.: 20,392 Region Association: None
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That is correct . 911 of that vintage had vacuum retard (not advance). The is the purpose for the 5 deg before TDS mark. That said the factory setting of that era are all about meeting emissions, not making the car run good. Many people when switching to carbs for example disconnect the vacuum retard system all together for better day to day driving performance.
john |
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Posts in this topic
Robarabian Question for Six Engine People Mar 15 2023, 08:48 PM
Robarabian I may have found the answer looking at 50 differen... Mar 15 2023, 08:57 PM Krieger I think the 5° BTDC is the timing mark at idle. I... Mar 15 2023, 10:33 PM ClayPerrine A suggestion for setting the cam timing.
Only pu... Mar 16 2023, 05:28 AM gereed75 I would emphasize one of Clays comments -put a dia... Mar 16 2023, 09:57 AM 930cabman I would double check with a dial indicator Mar 16 2023, 11:58 AM IronHillRestorations To add confusion the 2.4 and 2.7’s crank is inde... Mar 16 2023, 03:06 PM
Robarabian I was wondering about that. I installed a new flyw... Mar 16 2023, 06:45 PM Robarabian So my pulley actually has the Z1 mark and the seco... Mar 16 2023, 06:43 PM |
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