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| | | | Joined: Oct 2006 Posts: 125 Member | | Member Joined: Oct 2006 Posts: 125 | dont laugh....please explain advanced, retarded, late and early ignition timing. I am not asking "how to time", already know that. Just not really clear on the wording. If the book says "set timing to 12 degrees BTDC" and I set it to 8 degrees, is the timing now set "retarded" 4 degrees or "advanced" 4 degrees ?? and is it now "late" or "early"???
Carl
'58 3600 350/4-sp/stepside/big window cab
'59 3100 235/4-sp/stepside
| | | | | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | Carl,
No laughing. If the book says to set the timing to 12 degrees Before Top Dead Center and you set it to 8 degrees, you have set it to 8 degrees advanced. Anything Before Top Dead Center is advanced timing. Anything After Top Dead Center is retarded timing.
Advanced is Before, early, #1 fires before TDC.
Retarded is After, late, #1 fires after TDC
Top Dead Center is 0°, #1 piston is at the top of its compression stroke.
Stuart | | | | | Joined: Apr 2006 Posts: 236 'Bolter | | 'Bolter Joined: Apr 2006 Posts: 236 | Check out the explanation of ignition ssytems in internal combustion engines on the site "How Stuff Works." I think that it's pretty good, and a pretty cool site as well.
58 Fleetside, 235, "The Old Buckin' Bronco"
| | | | | Joined: Apr 2005 Posts: 1,971 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 1,971 | To add to automarc's reply;
If you are set at 12 degrees BTDC (12 degrees advanced from TDC), and you retard the timing (towards TDC) 4 degrees, you are now set at 8 degrees BTDC (8 degrees advanced from TDC.
12 degrees (BTDC or advanced)
- 4 degrees (retarded)
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8 degrees BTDC (or 8 degrees advanced) | | | | | Joined: Oct 2006 Posts: 125 Member | | Member Joined: Oct 2006 Posts: 125 | ok....these explanations really help. I was trying to explain timing to my son-in-law and realized I wasnt sure of the terms. So I quess that in the original question....12 degrees changed to 8 degrees the setting is now 8 degrees advanced ( a change of 4 degrees retarded). Any setting before TDC is advanced and any after is retarded, but I "retarded" the timing 4 degrees fron the original 12 degrees....that is what I was thinking and trying to explain to him but the more I tried the more confused we both got. Thanks guys... great place to pick brains here...  For best power is a setting closer to TDC the best choice???
'58 3600 350/4-sp/stepside/big window cab
'59 3100 235/4-sp/stepside
| | | | | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | cjoe, This is semantics. You 'retarded' the advance from 12° to 8°, but the timing is not 'retarded', it is 'advanced'...8° advanced! More advance will give you more power. Too much advance will cause problems...the engine will let you know when it has too much advance...listen and watch it's body temperature! Stuart | | | | | Joined: Oct 2006 Posts: 125 Member | | Member Joined: Oct 2006 Posts: 125 | thanks for the help Stuart. It was the semantics that had me scatching my head. I knew the answer, just wasnt able to explain it in words and the more I thought about it the more confusing the semantics became.
'58 3600 350/4-sp/stepside/big window cab
'59 3100 235/4-sp/stepside
| | | | | Joined: Apr 2005 Posts: 1,971 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 1,971 | We've all been there cjoe. | | |
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