Ignition Advance for 67 289

herkdriver · 12-30-2002, 01:51 PM

Ok, I have another question. According to Haynes repair manual, a 67 289 should be set to 6 degrees of advanced timing. Has anyone altered this setting, and adjusted it more than that. My car has an Edelbrock performer carb and intake, headers, and Accel super coil. Do any of these mild mods warrant a deviation from the factory spec timing?

herkdriver

Rev · 12-30-2002, 05:19 PM

Set it where it runs best without detonation or "pinging". Probably around 12-13 BTDC, (vacume advance disconnected).

Rev

herkdriver · 12-31-2002, 12:42 AM

Thanks for the info!!! I should warn you. I'm a beginner. In fact I bought the car so I could mess around with the engine a little.

I don't mean to question your advice, but 12-13 seems a bit high to me. Why would the manual say 6, but you recommend 12-13? I'm trying to learn about all this, so I'm only asking to get more educated.

In addition, you recommend retarding the ignition to 12-13 BTDC, but the timing marks on my car don't go below 6.

Would it help to attach a vacum gauge to the carb, as I adjust the timing, to make sure I'm taking advantage of max. vacum produced, and not loosing anything.

One last question.......should I be setting the timing with the car at idle, or with it operating at a particular RPM? The book doesn't specify, but the timing gun manual recommends operating the car at a higher RPM.

thunderbolt · 12-31-2002, 09:58 AM

Herk, you got some great questions for a beginner. I am sure more will chime in on this.

Regarding Rev's timing recomendations, you have some minor modifications to your engine which will change the optimal timing of the car. Second, the number the factory gives you is a very safe number that shouldn't cause detonation. However, more power can be gained by changing the timing to what Rev has recomended, excpeically with your modifications.

When you check this timing it should be at idle with the vacuum disconnected from the distributor. What you are checking is called the initial timing advance and in older cars is controled by the postion of the distributor. What you won't be checking with this method is the "advance curve" or how the engine advance changes with rpm. Inside the distributor are two weights that move further and further out as the engine revs faster. These weights are connected to a cam inside the distributor which changes the advance with changing engine rpm. So your total advance will be the initial advance plus advance from the mechanical advance. Finally, most distributors also have a vacuum canister attached to change the timing based on engine vacuum. This is usually for gas milage and most proformance distributors don't have vacuum advance. All three of these work together for engine advance.

I think Rev's recomendation is right on. I have seen as high as 16, but it is going to depend on your engine. If your timing marks only go to 6 you have a couple of options. 1. Get a timing tape and attach it to the ballancer, this will give you a wider range. 2. Get a dial back timing light. These are more expensive (paid 70 for mine) and will allow you to set the timing advance into the light.

You won't need a vacuum guage for timing, but this is the best way to set the idle screws on your carb, assuming they are adjustable. With the car ideling, adjust the screws until the maximum vacuum is reached. Readjust the idle speed to where you want it and then go after the idle screws again. It only takes a few minutes.

Once again, to set your initial timing you will want the car at an idle. If you want to plot out your advance curve you can take readings at different rpms, say every 500 up to 3500. You should have all your advance in by 3500. A distributor tech (or you can learn it yourself) can then adjust your advance curve for more power while the engine rpm's are changing.

Good luck, sounds like fun.

herkdriver · 12-31-2002, 10:21 AM

Thunderbolt and Rev

You guys rock!!! Thanks for the info. I rechecked the manual and I was wrong, it was 6 BDTC. I do have timing marks that go out past 12. I'm going to advance the timing a bit and see what happens. I don't have a tach on it yet, so the fancy timing you suggested will have to wait. While I'm at it, do you know how to get the original tach that was an option on the 67....it goes into dash on the rght side where the the oil pressure/altenator combo gauge is?

Heres my other question now. I've heard sometimes your engine can knock without you hearing it. How exactly will I know if its knocking?

Ok I lied, more questions. I realize that when you mod an engine, factory setting are out the door. But why do the mild mods (carb, intake, and headers) on my car warrant an increase in the timing? Is it because of more gas and air going in?

Finally, I also have a 1979 F100 302 with the same mild mods. Do you have a recommendation of the timing for it?

herkdriver

Rev · 12-31-2002, 03:42 PM

You can get the reproduction of the original "Rally Pack" for the '66 from Dallas Mustang, but it's going to be very expensive. It includes a clock and a tach that hangs off of both sides of the steering column. Unless your car is a concourse show car where originality is important, I would just get an inexpesive electronic tach from Auto Meter or Mallory for $50 or so.

It's true you can have detonation that you don't hear, especially at wide open throttle with loud pipes. Most people I know just keep advancing the spark until they hear it knocking or pinging and then retard it a couple of degrees from there.

Thunderbolt gave an excellent description of how spark advance works. Reread that post carefully and then get a book that goes into more detail about how to time the spark for best performance. HOW TO BUILD HORSEPOWER by David Vizard is an excellent book that explains a lot about high performance street engines (a little Chevy oriented), but still informative.

Rev

herkdriver · 12-31-2002, 07:06 PM

Rev

Thanks for the reply. I will do as you suggested. I advanced the timing to 8 BDTC, and it seemed to respond well.

I think I should have mentioned to that I don't have the stock, point ignition system under the cap. I have an electronic system. I think its called Protronix.

Does this make a difference with the timing?

Rev · 12-31-2002, 07:41 PM

Petronix changes from points to electroic ignition. Timing would be the same.

Rev

herkdriver · 01-01-2003, 05:04 PM

ok...great....thanks for the help!!!!!

12-30-2002, 01:51 PM	#1
herkdriver Registered Member Join Date: Dec 2002 Posts: 10	Ignition Advance for 67 289 Ok, I have another question. According to Haynes repair manual, a 67 289 should be set to 6 degrees of advanced timing. Has anyone altered this setting, and adjusted it more than that. My car has an Edelbrock performer carb and intake, headers, and Accel super coil. Do any of these mild mods warrant a deviation from the factory spec timing? herkdriver

12-30-2002, 05:19 PM	#2
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	advance Set it where it runs best without detonation or "pinging". Probably around 12-13 BTDC, (vacume advance disconnected). Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

12-31-2002, 03:42 PM	#6
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Rally Pack You can get the reproduction of the original "Rally Pack" for the '66 from Dallas Mustang, but it's going to be very expensive. It includes a clock and a tach that hangs off of both sides of the steering column. Unless your car is a concourse show car where originality is important, I would just get an inexpesive electronic tach from Auto Meter or Mallory for $50 or so. It's true you can have detonation that you don't hear, especially at wide open throttle with loud pipes. Most people I know just keep advancing the spark until they hear it knocking or pinging and then retard it a couple of degrees from there. Thunderbolt gave an excellent description of how spark advance works. Reread that post carefully and then get a book that goes into more detail about how to time the spark for best performance. HOW TO BUILD HORSEPOWER by David Vizard is an excellent book that explains a lot about high performance street engines (a little Chevy oriented), but still informative. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

12-31-2002, 07:41 PM	#8
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Petronix Petronix changes from points to electroic ignition. Timing would be the same. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

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12-31-2002, 12:42 AM	#3
herkdriver Registered Member Join Date: Dec 2002 Posts: 10	Thanks for the info!!! I should warn you. I'm a beginner. In fact I bought the car so I could mess around with the engine a little. I don't mean to question your advice, but 12-13 seems a bit high to me. Why would the manual say 6, but you recommend 12-13? I'm trying to learn about all this, so I'm only asking to get more educated. In addition, you recommend retarding the ignition to 12-13 BTDC, but the timing marks on my car don't go below 6. Would it help to attach a vacum gauge to the carb, as I adjust the timing, to make sure I'm taking advantage of max. vacum produced, and not loosing anything. One last question.......should I be setting the timing with the car at idle, or with it operating at a particular RPM? The book doesn't specify, but the timing gun manual recommends operating the car at a higher RPM.

12-31-2002, 09:58 AM	#4
thunderbolt Registered Member Join Date: Oct 1998 Location: Houston, TX, USA Posts: 380	Herk, you got some great questions for a beginner. I am sure more will chime in on this. Regarding Rev's timing recomendations, you have some minor modifications to your engine which will change the optimal timing of the car. Second, the number the factory gives you is a very safe number that shouldn't cause detonation. However, more power can be gained by changing the timing to what Rev has recomended, excpeically with your modifications. When you check this timing it should be at idle with the vacuum disconnected from the distributor. What you are checking is called the initial timing advance and in older cars is controled by the postion of the distributor. What you won't be checking with this method is the "advance curve" or how the engine advance changes with rpm. Inside the distributor are two weights that move further and further out as the engine revs faster. These weights are connected to a cam inside the distributor which changes the advance with changing engine rpm. So your total advance will be the initial advance plus advance from the mechanical advance. Finally, most distributors also have a vacuum canister attached to change the timing based on engine vacuum. This is usually for gas milage and most proformance distributors don't have vacuum advance. All three of these work together for engine advance. I think Rev's recomendation is right on. I have seen as high as 16, but it is going to depend on your engine. If your timing marks only go to 6 you have a couple of options. 1. Get a timing tape and attach it to the ballancer, this will give you a wider range. 2. Get a dial back timing light. These are more expensive (paid 70 for mine) and will allow you to set the timing advance into the light. You won't need a vacuum guage for timing, but this is the best way to set the idle screws on your carb, assuming they are adjustable. With the car ideling, adjust the screws until the maximum vacuum is reached. Readjust the idle speed to where you want it and then go after the idle screws again. It only takes a few minutes. Once again, to set your initial timing you will want the car at an idle. If you want to plot out your advance curve you can take readings at different rpms, say every 500 up to 3500. You should have all your advance in by 3500. A distributor tech (or you can learn it yourself) can then adjust your advance curve for more power while the engine rpm's are changing. Good luck, sounds like fun.

12-31-2002, 10:21 AM	#5
herkdriver Registered Member Join Date: Dec 2002 Posts: 10	Thunderbolt and Rev You guys rock!!! Thanks for the info. I rechecked the manual and I was wrong, it was 6 BDTC. I do have timing marks that go out past 12. I'm going to advance the timing a bit and see what happens. I don't have a tach on it yet, so the fancy timing you suggested will have to wait. While I'm at it, do you know how to get the original tach that was an option on the 67....it goes into dash on the rght side where the the oil pressure/altenator combo gauge is? Heres my other question now. I've heard sometimes your engine can knock without you hearing it. How exactly will I know if its knocking? Ok I lied, more questions. I realize that when you mod an engine, factory setting are out the door. But why do the mild mods (carb, intake, and headers) on my car warrant an increase in the timing? Is it because of more gas and air going in? Finally, I also have a 1979 F100 302 with the same mild mods. Do you have a recommendation of the timing for it? herkdriver

12-31-2002, 07:06 PM	#7
herkdriver Registered Member Join Date: Dec 2002 Posts: 10	Rev Thanks for the reply. I will do as you suggested. I advanced the timing to 8 BDTC, and it seemed to respond well. I think I should have mentioned to that I don't have the stock, point ignition system under the cap. I have an electronic system. I think its called Protronix. Does this make a difference with the timing?

01-01-2003, 05:04 PM	#9
herkdriver Registered Member Join Date: Dec 2002 Posts: 10	ok...great....thanks for the help!!!!!