Distributor Advance

[ew1usnr]

I have a 1960 - 1962 service manual with a 1963 V-8 supplement. The manual provides vacuum advance specifications for a six cylinder but not for an eight.

Someone might have this information in a 1964 service manual. I am looking for the mechanical and vacuum advance ranges for the distributors that would have gone with a 1963 Falcon manual transmission and an Ford-O-Matic transmission.

I found this information for a 1965 Mustang, but it applies to a 289 with a three-speed automatic.

5864

See: http://www.mustang-s.com/years/1965/1965_distributors.htm

Is there any similar site for 1963 Falcon distributors?

I want to know how the timing advance for an automatic differed from one for a manual. Now you can get a universal distributor for "Ford 221, 260, 289, 302", but back in the day the distributors were specific to the transmission type.

Thanks, Dennis.

Summary: "For a 289 V-8 with a three-speed automatic, the centrifugal weights function through the 450 - 2000 RPM range (10 - 44 mph) and add 12 degrees of advance. The vacuum advance functions at higher engine speeds for additional advance and operates from 8 to 14 inches of mercury vacuum to provide 11 degrees of advance. The combined total equals 23 degrees of advance."

[ew1usnr]

I am looking for the mechanical and vacuum advance ranges for the distributors ...

After reading about the centrifugal and vacuum advances, I realized that I had never tested the vacuum advance canister on my distributor.

After dinner tonight, I slipped a two-foot long piece of tubing onto the nipple of the distributor vacuum advance and sucked on it. I could not pull any air through it and that indicates that it is working. Yay!

Happy Banana Dance: :banana:

If I did need to replace the vacuum advance on a 1963 260 V-8 with a Ford-O-Matic, which of these units would be the most correct replacement?

5865

See: http://www.oreillyauto.com/site/c/search.oap?keyword=distributor+vacuum+advance&year=1963&make=Ford&model=Falcon&vi=1334786

All three of the ones on the right with nipples are listed as being compatible with my 260. But, ... they reference some distributor numbers. Which number would be most likely to match my distributor?

Thanks, Dennis.

[Luva65wagon]

Dennis,

I have a lot of books and such, but have not been at home other than to sleep for about 2 weeks straight. If I didn't force myself to take a break at work once in a while, I'd never post anything. I plan to be home on Friday ( :banana: ) so I will look a bit for you re: these specs.

As for the correct one of the replacement advances, they are not indicating what the differences are between them, other than the model numbers of the distributors. Your distributor should have a stamped Ford model number (something C2xx or C3xx), so perhaps you can find that.

Sucking on the hose doesn't mean it is doing the job. Only means the diaphragm doesn't have a hole in it. You need to pull the cap and watch the plate move as well. Same holds true with the mechanical advance. And you don't know whether someone hasn't swapped out springs to change the curve. If the point plate is moving easily by hand as well, chances are the other bits will at least move it too - but it's good to check it both visually and watching the timing marks with the engine running.

[ew1usnr]

Hello, Roger.


As for the correct one of the replacement advances, they are not indicating what the differences are between them, other than the model numbers of the distributors. Your distributor should have a stamped Ford model number (something C2xx or C3xx), so perhaps you can find that.

I will take a look. Finding that number would allow me to match a vacuum advance to the distributor that I have. The distributor that is on the car now might not necessarily be the same as the distributor that originally came with the car.

5867


Sucking on the hose doesn't mean it is doing the job. Only means the diaphragm doesn't have a hole in it. You need to pull the cap and watch the plate move as well. Same holds true with the mechanical advance. And you don't know whether someone hasn't swapped out springs to change the curve. If the point plate is moving easily by hand as well, chances are the other bits will at least move it too - but it's good to check it both visually and watching the timing marks with the engine running.

Can a person suck hard enough to visually move the breaker plate?
I can move the plate with my fingers, but it seems to have some spring tension.
I have a transparent distributor cap. Should I be able to see the vacuum advance move the breaker plate if my wife revs the engine above 2000 RPM?

5866

Thanks, Dennis.

[Luva65wagon]

Can a person suck hard enough to visually move the breaker plate?
...

Should I be able to see the vacuum advance move the breaker plate if my wife revs the engine above 2000 RPM?

You may not be able to suck on it with your mouth hard enough to see full advance, but it should move the plate until the mechanical advance springs make it too hard to. There is also a spring, IIRC, in the vacuum advance can, so it varies the curve it can apply.

Also, with the timing light hooked up, but with NO vacuum advance connected, rev the motor up smoothly and watch the timing marks. This will show the RPM-based mechanical advance curve.

You could hook up a timing light and start the car. With the engine idling hook up and remove the vacuum line. You should see some movement of the timing mark. You can also tap into a full vacuum port somewhere, or use a vacuum hand pump, and pull a full vacuum on the distributor. See how much it will move the timing mark

FWIW I wouldn't expect the advance curves to vary much from the information you posted originally in the tables above. Over 50 years you have no idea if things haven't changed, as you say, so it's a pretty good starting place to see how it differs from the data you have. Keep in mind as well that there is a significant difference in the fuels we have today and what was good (in regard to advance curves) in 1963 may not be ideal using our ethanol-infused lead-less 87 octane fuels.

[ew1usnr]

You may not be able to suck on it with your mouth hard enough to see full advance, but it should move the plate until the mechanical advance springs make it too hard to. There is also a spring, IIRC, in the vacuum advance can, so it varies the curve it can apply.

Hello, Roger.

I couldn't budge it by sucking on it. I can swing the plate with a screwdriver tip, but it had a definite spring tension on it.


Also, with the timing light hooked up, but with NO vacuum advance connected, rev the motor up smoothly and watch the timing marks. This will show the RPM-based mechanical advance curve.

I have a timing light somewhere and will have to try to find it. It would be an interesting weekend project to examine the timing at different RPMs.


Keep in mind as well that there is a significant difference in the fuels we have today and what was good (in regard to advance curves) in 1963 may not be ideal using our ethanol-infused lead-less 87 octane fuels.

Good point. The engine did seem to run smoother and more responsively when I tried 89 octane ethanol-free gas.

I thought that it was cool how the specifications for an automatic said that the mechanical advance started at 450 RPM. That just happens to also be the correct idle speed. It makes sense that you would want the least advance when the car is at idle. Less advance lets you hold flaming gasoline in the cylinders for the shortest time. That helps to keep the car cooler when it is not moving and has the least air flow through the radiator. You can safely advance the spark and increase engine heat when the car is moving and is better dissipating heat from the radiator. The mechanical advance hits its maximum at 2000 RPM which is about 44 mph.

[ew1usnr]

I have a timing light somewhere and will have to try to find it. It would be an interesting weekend project to examine the timing at different RPMs.

Dang it. I could not find my Sears timing light. The last time that I saw it was five years ago. Yesterday evening I looked in boxes in the garage and in the attic and could not find it.

Last night I bought a Made in USA "New Actron 12v Solid State Inductive Timing Light CP7504" off e-bay for $29.99 including postage from Manhattan, Kansas (98 sold). "These Actron timing lights have a molded inductive pick-up, which clamps over spark plug wire to make hookup easy. They include heavy-duty 6 ft. leads with color-coded insulated battery clamps, a power tool trigger switch, a linear xenon flash tube, and a focused Fresnel lens that provides light bright enough for use in broad daylight."

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People will say, "He was not fast, but his timing was perfect." :)


Keep in mind as well that there is a significant difference in the fuels we have today and what was good (in regard to advance curves) in 1963 may not be ideal using our ethanol-infused lead-less 87 octane fuels.

I found this quote: "...in 1962 the average octanes of gasoline in the U.S. now stood at 93 for regular, 99 for premium and 102 for the few super-premiums ...".
See: http://www.stevesnovasite.com/forums/archive/index.php/t-164646.html

Also see: http://www.tommcmahon.net/2010/08/sunoco-blendomatic-gas-pump.html

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A 93 octane gasoline would allow a greater spark advance than would a lower octane. So, should the spark should be retarded from the original factory advance specification if an engine is burning modern lower 87-octane regular gasoline?

My 260 with an automatic is set at its original timing specification of 8 degrees advance. I have never had pinging while running on 87-octane regular so the timing does not need to be retarded.
In theory though, it seems like it should need to be.

5870

Update -

A astute and helpful individual (Ivy66GT in Albuquerque) on a Mustang board provided the following detailed explanation regarding octane ratings:

"The octane numbers you quote are not measured on the same scale. When these cars were new the required octane was a research octane number (RON). That number is always higher than the motor octane number (MON) which is measured slightly differently although using the same test engine. The difference between the two (RON-MON) is called 'fuel sensitivity' and for today's regular it is usually ~10. Premium grade sensitivity is 11-12. Most anywhere except in North America pumps are still labeled with RON so that 95 octane you read about in Europe is not 'better' than ours since it would be an 89 or 90 if it was in a US pump.

I am not sure of the date but let's say about the mid-70s the feds decided that all US gasoline pumps were to be labeled with a new number called pump octane = (RON+MON)/2 which is sometimes shortened to (R+M)/2. (Look for it on the pump when next you buy gas.) That means that the 87 regular you buy today would be 87 + (10/2) = 92 on the scale used in 1966. Regular in the US today varies anywhere from 85 to 89 (pump) or 90 - 94 RON so its not that much, if any, different octane than it was 50 years ago. The same applies to premium. Today's 93 octane is 93 + (12/2) = 99 on the scale of yesteryear.

So, its not surprising that you have no pinging since that is perfectly normal. You will find several owners today who use MORE advance than Ford specified rather than less. Many weather factors affect the octane number requirement (ONR) of an engine. The three biggest are humidity, altitude and temperature. The first 2 reduce ONR while temperature increases it. At our mile+ altitude ONR is reduced 9 octane which explains how we can use regular 85 every day of the year even for engines that might need premium at sea level. In Tampa you are at sea level but your high humidity reduces ONR about 5 octane compared to a drier climate like ours. Temperature isn't as important since it takes a 20F rise to affect ONR by 1 octane.

The real test of how much octane you need would be driving in Death Valley in 100F+ temps: dry, below sea level and hot. Its those kinds of conditions which were (and still are) used to specify octane and advance for an engine. Most of us not in Death Valley can use less octane and/or advance the ignition more than specified."

[SmithKid]

Dennis, It's always seemed to me that various engine setups are always slightly different, but a good rule of thumb I've used is to advance the timing until you hear a slight ping, then retard just a bit at a time until the ping disappears under all conditions (or possibly the very hardest pull). This should produce the most power, but not necessarily the smoothest idle. You should find a good balance of idle/power setting.

I've always figured that factory recommended settings are for "Joe Average Guy" that doesn't do the maintenance/tune that we as enthusiasts do.

[ew1usnr]

Dennis, It's always seemed to me that various engine setups are always slightly different, but a good rule of thumb I've used is to advance the timing until you hear a slight ping, then retard just a bit at a time until the ping disappears under all conditions (or possibly the very hardest pull). This should produce the most power, but not necessarily the smoothest idle. You should find a good balance of idle/power setting.

Hello, Gene.

My 260 V-8 with an automatic is specified to have a base advance of 8 degrees.
A mechanical engineer buddy of mine at work says that he has his 1967 Fairlane with a 302 and an automatic set at 14 degrees advance.

The timing light will let me confirm where my present timing is, and then I can experiment with advancing the timing a couple of degrees at at a time. I can then watch the engine temperature, idle smoothness, listen for pinging, etc. If there are any negatives I can always put the timing back to where it was to start with. Maybe I can try seasonal variations and run with more advance when the weather is cooler, and less when the weather is hot to reduce the engine temperature.

If I start adjusting the timing, does that mean that I will be what they call a "tuner"?

5871

[SmithKid]

Nowadays, I think "tuner"has come to mean "rice-burner". I don't think The Wonder Falcon qualifies!

[ew1usnr]

My 260 V-8 with an automatic is specified to have a base advance of 8 degrees.
A mechanical engineer buddy of mine at work says that he has his 1967 Fairlane with a 302 and an automatic set at 14 degrees advance.

I tried my new timing light last week and found that the engine was set to 10 of advance.
When I advanced the timing to 14 and the idle speed increased from 450 to 550 RPM. That seemed to indicate that the engine was running more efficiently, so I left the timing at 14.
I then deliberately drove the car in stop and go traffic while the air temperature was 91 degrees and the engine did not seem to run any hotter than it had previously. The temperature gauge stayed at mid-range and there was no problem. The engine did not ping when it was accelerated from 0 to 65 mph or when the car was driven on the Interstate at 80 mph. The car starts instantly, idles smoothly and quietly, and there did not seem to be any negatives from having advanced the timing. The car felt like it had more power while zooming up the interstate on-ramp, but that might have just been my imagination. I will see if advancing the timing has improved the gas mileage. That would be nice.

Then I wondered how much total advance the engine was getting at higher speeds.

Background: The previous owner had "hot rodded" my 260 with an aluminum intake manifold, a four-barrel carburetor, and some other stuff.
I put everything back to stock when the engine was rebuilt four years ago. I assumed that the old distributor was good, so I re-installed it on the rebuilt motor.

The stock distributor is supposed to have 14 degrees of mechanical advance maximum.

5913

Present: I bought a set of vacuum caps ($2.99) so that I could seal off the vacuum advance to find how much mechanical advance the distributor was providing:

5914

Yesterday evening I sealed off the vacuum advance and had my neighbor rev the engine while I looked at it with a timing light.

At 550 RPM idle the advance was 14.
At 1000 RPM the advance was 16.
At 2000 RPM the advance was 32.
At 2500 RPM the advance was 36.

36 - 14 initial = 22 degrees of mechanical advance. That is greater than the 14 degrees maximum that the stock distributor is supposed to have.
I think that the previous owner did something with this distributor. I found this quote that may explain it: "Stock Ford distributors have two slots. There is a pin that sits in one of the slots to limit travel. To change slots you simply remove the armature assembly turn it 180 degrees and reinstall it so the pin is in the other slot. The slots are numbered as to how many distributor degrees it will pull in, double it to find the amount of crank degrees. So if you want 24° mechanical advance you need to find an armature assembly with a slot marked 12L." From "Distributor advance": http://www.gofastforless.com/ignition/advance.htm The previous owner may have done this to double the mechanical advance from 12 to 24.

Not that this is necessarily a bad thing. In "How to Set Your Timing for Peak Performance", See: http://outintheshop.com/faq/Lars%20timing%20.pdf the author says ""Small block Chevys (and most other performance V8 engines) perform best when the total timing (full centrifugal advance plus the initial timing setting with vacuum advance disconnected) and is set to 36 - 38 degrees at 2,500 - 2,800 rpm. The 36-degree 2500 rpm advance curve is optimum for performance (but retard the timing if there is pinging).”

My engine is spot on with this advice and it has 36 degrees advance at 2500 RPM. My little 260 is "tuned for peak performance" with the same timing as a vintage Corvette. It does not ping or run hot, it idles steady, starts easy, and runs great. Yaaay!!

5915

[ew1usnr]

36 - 14 initial = 22 degrees of mechanical advance. That is greater than the 14 degrees maximum that the stock distributor is supposed to have.

Upon further study, I found that distributor degrees equate to double their number in crankshaft degrees. That was what the author that I quoted meant when he said "... how many distributor degrees it will pull in, double it to find the amount of crank degrees." So, the 22 degrees of crank advance means 11 degrees of distributor advance.

Since I do not know what is the advance curve my for distributor, I do not know how much distributor advance was contributed to the 14 degrees total advance that I had at 600 RPM.

I read that the advance at idle is not as important as what the total advance is while the car is moving. The important indicator was that I had 36 degrees total advance at 2500 RPM.

The engine ran great. It started easy, and did not ping.

In "How to Set Your Timing for Peak Performance", the author said "performance V-8 engines perform best when the total timing (full centrifugal advance plus the initial timing setting with vacuum advance disconnected) and is set to 36 - 38 degrees at 2,500 - 2,800 rpm."

So, I slowed the idle back down to 500 RPM and then moved the advance from 14 to 16, giving 38 degrees of advance at 2500 RPM.

I have been driving the car to work each day and the advanced timing has not caused any pinging or difficulty in starting the engine. The car actually seems to run a lot better. I cannot back this up with numbers, but the engine feels more lively and it seems to accelerate quicker. It feels like the engine has woken up and that the Challenger 260 has come alive. I step on the gas and the car jumps up and the exhaust makes a wonderful "WOOOOOO" sound. It is so nice. It is so much fun to press the gas and go that I find that I am driving more quickly now. I look at the speedometer and see that I am going 60 and have to slow down. The Wonder Falcon is performing like a sports car! :)

[MacDee]

I have been watching this string with some interest. You see, I think I may have a “problem” with the curve in my distributor. Long story; I’ll try to keep it as brief as possible.


Right after we (Pat) got my first 200 engine to idle, it still had a problem with very poor throttle response. You’d push on the gas, and it would go flat before it picked up and went (if you were lucky). First thing I tried to do to improve the situation was to monkey with the advance curve.
I had read an article on Ford Six Performance Forum suggesting that improvements could be made by replacing one of the flyweight springs with a lighter one. I’d seen another article about tuning that cautioned not to exceed about 38 degrees total advance (mechanical plus initial), and that the mechanical advance could be modified somewhat by installing the flyweights differently. So… I took my distributor out, managed (with some difficulty) to take it apart, flipped the weights to maximum advance orientation, and replaced the heavier of the two springs with a light one from a “curve kit” that I got from I-don’t-remember-where (probably Summit).
A test drive confirmed that the throttle response was significantly better, but still not very good. If some is good… Well, more is…. I took the distributor apart again… this time without even taking it out of the car… and replaced the OTHER heavier spring with the other light spring from the curve kit. Throttle response was better still.
(Eventually, throttle response was made good with changes to the main jets, from #51 to #57, but that’s another story and off the point here.)
Anyhoo…
The engine is now PROFESSIONALLY rebuilt with a new, milder, cam (264 deg), and it runs really well. Except for the sound it makes when I get on it. When I push it hard, the engine sounds… unhappy. It makes an awful, screechy, anxious sound, and I’m wondering if it might be detonation. As far as I know, those light springs are still in there, but my new cam has an earlier intake close event, which will increase compression pressure at lower engine speeds, so I’m concerned that now my curve might be TOO FAST for the new cam.

Recently I managed to work up the ambition to do a test similar to what Dennis did, and checked the total advance vs. RPM.
Currently, the initial advance is 10 degrees BTDC. By using a combination of my standard timing light and my variable one, I was able to confidently determine the curve is as follows:
(vacuum line disconnected)
10 degrees @ 800 rpm idle (as slow as I can get it to idle);
15 degrees @ 1200 rpm;
25 degrees @ 1600 rpm;
30 degrees @ 2000 rpm;
37 degrees @ 2400 rpm.

Based on the numbers stamped on the weights, I was expecting… I assumed… I was getting 13 degrees of advance maximum per weight, or 26 total degrees of mechanical advance. The figures say 27 degrees at 2400, so I’d say that’s in the ballpark… EXCEPT that I didn’t think to run the engine up past 2400 to see if the mark continued to rise! I’ll need to work up some more ambition, and go run it again.
As you can see, these numbers are MUCH more aggressive than the curve in Dennis’ distributor, and I would very much like to try it with at least one of the heavier springs back in the distributor, but I just can’t work up the courage… the will?... find the time?... to work on it again.


Does anyone have some sage advice to offer on this topic?


Does anyone have a bottle of gumption, or at least a round tuit I can borrow?


I've got a couple of serious looky-loo's for the car. One of them told me he might want to just come get it and drive it home... to Georgia!! I'd really like put my mind to rest on this before I deliver it to anybody!

[ew1usnr]

I was able to confidently determine the curve is as follows:
(vacuum line disconnected)
10 degrees @ 800 rpm idle (as slow as I can get it to idle);
15 degrees @ 1200 rpm;
25 degrees @ 1600 rpm;
30 degrees @ 2000 rpm;
37 degrees @ 2400 rpm.

As you can see, these numbers are MUCH more aggressive than the curve in Dennis’ distributor ...

Are your numbers crank degrees or distributor degrees (1/2 of crank)? If they are crank degrees they look close to the crank degrees that other people are using.

The numbers on the left came from the following referenced link to a timing discussion. The middle numbers are mine, and yours are on the right. My numbers are actually a little bit more advanced than yours, but all three sets are similar to one another:

5946

See: http://www.allfordmustangs.com/forums/classic-tech/991145-timing-advice.html

I found this reference for a 260 with an automatic. It does not say whether a 2-speed or 3-speed automatic, but is probably close to what I am supposed to have:

5947

I took my measured numbers, subtracted 4 degrees to take it back to the stock initial 8 degree advance and subtracted half the remaining to represent the distributor advance. Then I charted the stock 260 distributor curve in blue and my distributor curve in red. I was surprised to find that they are relatively close:

5948

I think that the car was set to the stock 8 degrees of initial timing. Then I advanced it 4 degrees to 12, and then 2 more degrees to 14. That means that I am now running 6 degrees advanced over the stock 8 degree initial advance.

[ew1usnr]

I am now running 6 degrees advanced over the stock 8 degree initial advance.

Leaving my timing advanced 6 crank degrees over the base timing of 8 crank-degrees seemed to give the best performance without pinging.

A 6-degree over-advance also just happens to be indicated as the near optimal timing in this graph that I found in a Chilton's repair manual for Pinto/Bobcat 1971 - 1980:

5961

The graph shows that a 6-degree over-advance provides a 2.25% gain in power at the expense of a moderate 7% rise in spark plug temperature.

My car may not be fast, but its timing is perfect. :)