bobioknight
Member
Hey guys, I am confused about timing, the manual for my 1957 thunderbird 312 ybock states 6* at 500rpm. But I see people posting that they run better at 12*. I hope this is not too confusing to read.
So I have been experimenting with different degrees but I don't want to hurt my engine, economy or overheat, so I am curious if I am doing this correct.
So I connect my timing light, my vacuume gauge and remove the vacuum advance and plug the carb port, loosen my distrib and get ready for adjustments. Start the engine, let it warm up completely. Set my timing light to 12* and adjust the dizzy until the marks are at tdc.
As I adjust my dizzy the rpm's increase so I continually increase or decrease & the vacuume increases and decreases depending on the direction I turn the dizzy. I make little adjustments at a time allowing each adjustment to kinda balance out.
So what I experience is when I am at 12* at 500 rpm, I don't have as much vacuume as when I am at let's say 8* at 500rpm. Also at 12* my idle is a bit higher than I can adjust the carbeurator down to so I can only adjust the idle screw down to 500 rpm and no lower. If I set to 8* then I can lower my idle by adjusting the screw on the carb way lower. At 12* it seems to be a little harder to start like the starter has to pickup speed to get it going. At 12* my vacuum is at approx 18 whereas at 8* the vacuum is a bit over 19.
So my first question is when I am adjusting my initial timing, do I adjust the idle keeping it at a constant 500rpm, I ask this because as the idle rpm's change the timing mark changes as well, is this normal. As I advance timing, the rpm's my go to 550, when I reduce the rpm's back to 500 I may have to adjust the timing a little more until they both are balanced depending on the number I am trying to hit.
Second question, total timing, let's say 35* at 2500 rpm, is this the most important timing setting. Should I set this first and see where my idle timing ends up.
Third, if the manual calls for 6* should I set my timing to 6* if I have the most vacuum at that setting. Or do I stop focusing on hitting an exact timing number and just focus on vacuum by advancing the timing until the vacuum stops increasing?
Forth I have read, keep advancing timing until it pings on load then back it down a little, well I am not pinging yet at 12*, does that mean I could keep advancing further like to 16*, but although that might not ping I expect my vacuum would be much lower the further it is advanced making it even harder to start.
Fifth, timing vs heat, if I set timing to 6* I think it runs hotter and less fuel economy. The more I have advanced the timing I think it runs cooler and I feel my fuel economy increased. So do I just need to find a good balance, like 8 or 10, or the highest vacuum?
people say "it just sounds happy" well that's tough, because the more advance the happier it sounds because the idle is going up which makes everything sound very smooth, idling down at low rpm's sounds a bit rougher, but I have never heard pinging or knocking, I always run premium fuel so maybe it covers up timing issues.
So I have been experimenting with different degrees but I don't want to hurt my engine, economy or overheat, so I am curious if I am doing this correct.
So I connect my timing light, my vacuume gauge and remove the vacuum advance and plug the carb port, loosen my distrib and get ready for adjustments. Start the engine, let it warm up completely. Set my timing light to 12* and adjust the dizzy until the marks are at tdc.
As I adjust my dizzy the rpm's increase so I continually increase or decrease & the vacuume increases and decreases depending on the direction I turn the dizzy. I make little adjustments at a time allowing each adjustment to kinda balance out.
So what I experience is when I am at 12* at 500 rpm, I don't have as much vacuume as when I am at let's say 8* at 500rpm. Also at 12* my idle is a bit higher than I can adjust the carbeurator down to so I can only adjust the idle screw down to 500 rpm and no lower. If I set to 8* then I can lower my idle by adjusting the screw on the carb way lower. At 12* it seems to be a little harder to start like the starter has to pickup speed to get it going. At 12* my vacuum is at approx 18 whereas at 8* the vacuum is a bit over 19.
So my first question is when I am adjusting my initial timing, do I adjust the idle keeping it at a constant 500rpm, I ask this because as the idle rpm's change the timing mark changes as well, is this normal. As I advance timing, the rpm's my go to 550, when I reduce the rpm's back to 500 I may have to adjust the timing a little more until they both are balanced depending on the number I am trying to hit.
Second question, total timing, let's say 35* at 2500 rpm, is this the most important timing setting. Should I set this first and see where my idle timing ends up.
Third, if the manual calls for 6* should I set my timing to 6* if I have the most vacuum at that setting. Or do I stop focusing on hitting an exact timing number and just focus on vacuum by advancing the timing until the vacuum stops increasing?
Forth I have read, keep advancing timing until it pings on load then back it down a little, well I am not pinging yet at 12*, does that mean I could keep advancing further like to 16*, but although that might not ping I expect my vacuum would be much lower the further it is advanced making it even harder to start.
Fifth, timing vs heat, if I set timing to 6* I think it runs hotter and less fuel economy. The more I have advanced the timing I think it runs cooler and I feel my fuel economy increased. So do I just need to find a good balance, like 8 or 10, or the highest vacuum?
people say "it just sounds happy" well that's tough, because the more advance the happier it sounds because the idle is going up which makes everything sound very smooth, idling down at low rpm's sounds a bit rougher, but I have never heard pinging or knocking, I always run premium fuel so maybe it covers up timing issues.
