Ignition timing question
Thread Starter
Track Day
Joined: Dec 2001
Posts: 15
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From: New Jersey
Ignition timing question
I just built and installed a 1979 engine in my 1975 911. I built the engine with a Max Moritz 3.2 litre big bore kit with 9.8 to one compression. I had my cams ground to 964 specs.What ignition timing would give me the best performance? Should I use the stock 5 degrees BTDC or I have been reading about full advance settings at 6000 rpm.If full advance settings would give the best perfomance, what are the settings. Thanks for any help.
RL Technical Advisor
Joined: May 2001
Posts: 11,870
Likes: 75
From: Portland Oregon
[quote]Originally posted by 75eleven:
<strong>I just built and installed a 1979 engine in my 1975 911. I built the engine with a Max Moritz 3.2 litre big bore kit with 9.8 to one compression. I had my cams ground to 964 specs.What ignition timing would give me the best performance? Should I use the stock 5 degrees BTDC or I have been reading about full advance settings at 6000 rpm.If full advance settings would give the best perfomance, what are the settings. Thanks for any help.</strong><hr></blockquote>
Hi Joe:
The most important timing value by far, is the one at 6000 RPM. It matters little what it comes out at idle, except for emissions in some cases.
Make sure that you have no more than 34-35 deg at 6000 RPM as all of the centrifugal advance is in by then. If you need more or less timing at idle or at 3000 RPM, then you can have your distributor recurved. I think you'll find that setting total advance at 6000 will work fine for you.
<strong>I just built and installed a 1979 engine in my 1975 911. I built the engine with a Max Moritz 3.2 litre big bore kit with 9.8 to one compression. I had my cams ground to 964 specs.What ignition timing would give me the best performance? Should I use the stock 5 degrees BTDC or I have been reading about full advance settings at 6000 rpm.If full advance settings would give the best perfomance, what are the settings. Thanks for any help.</strong><hr></blockquote>
Hi Joe:
The most important timing value by far, is the one at 6000 RPM. It matters little what it comes out at idle, except for emissions in some cases.
Make sure that you have no more than 34-35 deg at 6000 RPM as all of the centrifugal advance is in by then. If you need more or less timing at idle or at 3000 RPM, then you can have your distributor recurved. I think you'll find that setting total advance at 6000 will work fine for you.
