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Old 07-27-2022, 06:05 AM   #1
Lenny Bruce
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Default Timing advance

Hello guys! I’m finally starting to really being able to enjoy my Model A. One question I have is about the advanced timing. It’s intimidating to me because of all the different opinions on how it should be used. I guess my question is when driving around town and on the highway is it ok to run it fully advanced? My car really likes to be near if not fully advanced most of the time. I’ve heard so many horror stories one of which it will chew up head gaskets? I did watch a Jack Bahm
Video he says he always ran his fully advanced… Any input would be greatly appreciated…
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Old 07-27-2022, 06:42 AM   #2
nkaminar
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Default Re: Timing advance

Advance the timing to the point where the car is running best but no further. You can do that at a fast idle, about 1,200 rpm. As you advance the timing the engine will run faster until a further notch of the advance lever will not produce a greater rpm. Retard the timing one notch from that point and that is the point where you can run the car most of the time. This position of the timing lever will be different for different cars. For one car it may be almost to full advance and for another at 9 o'clock. This is called the knee in the advance curve. The knee may change over time as the points wear or if you re time the engine or do any changes like use a higher compression ratio head.

You can use this trick for different driving conditions like going up a grade. The timing is usually retarded one notch when the engine is under load especially at lower rpm's. It can usually be advanced one notch when driving at a cruising speed with reduced throttle.

The science behind the timing advance is that it takes some time for the fuel to burn and produce maximum pressure. The maximum pressure should be just when the piston is at the top. More timing advance and the maximum pressure is before the piston reaches the top. A more retarded ignition advance means that the maximum pressure is after the piston reaches the top.

If you have good ears you can hear knocking when the timing is too advanced. This knocking is bad for the connecting rod bearings and can ruin them quickly if too severe.
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Last edited by nkaminar; 07-27-2022 at 06:48 AM.
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Old 07-27-2022, 07:00 AM   #3
Lenny Bruce
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Default Re: Timing advance

That’s great information thank you!!
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Old 07-27-2022, 10:48 AM   #4
Bob C
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Default Re: Timing advance

This is from the Ford owners manual.


The Spark Control For average driving the spark lever should be carried about half way down the quadrant. Only for high speeds should the spark lever be advanced all the way down the quadrant. When the engine is under a heavy load as in climbing steep hills, driving through heavy sand, etc., the spark lever should be retarded sufficiently to prevent a spark knock.
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Old 07-27-2022, 01:06 PM   #5
Lenny Bruce
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Default Re: Timing advance

Very interesting! If I leave my driveway and start to climb the hill it wants to be advanced.
Has much more power for the hill but I will definitely try it otherwise. Thanks!
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Old 07-27-2022, 03:25 PM   #6
nkaminar
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Default Re: Timing advance

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Lenny, Your car is unique. The instructions from the owner's manual do not apply to your car. Move the lever to where the car runs best but no further. If too retarded it will burn valves and the power will be severely compromised, and you will waste gasoline. Plus, when those instructions were written the gasoline had a lot lower octane rating and would knock if you looked at it sideways.
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A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
My car grows red hair, and flies through the air.
Driving's a blast, a blast from the past.
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Old 07-27-2022, 04:09 PM   #7
alexiskai
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Default Re: Timing advance

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Originally Posted by nkaminar View Post
Your car is unique. The instructions from the owner's manual do not apply to your car.
Reminds me of a YouTube video I saw last week where the guy pulled the spark lever all the way down to start the car and then put it back up to run. Whatever works for your car, man, do that thing.
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Old 07-27-2022, 04:26 PM   #8
Lenny Bruce
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Default Re: Timing advance

Yes sir it’s definitely starting to look like all A’s have their sweet spot. I’ve only had my A for a few months and have driven it around the back roads getting a feel for it. I’ll just keep getting things down and Cruze on! Thank you all for the feedback. I love learning about The model A every day thanks to friendly folks like yourselves!
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Old 07-28-2022, 07:42 AM   #9
Bob Bidonde
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Default Re: Timing advance

Ford instructions for driving the Model "A" are based upon the gasoline available when the car was new. The instructions are not applicable to modern gasoline. Find your engine's sweet spot.
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Old 07-28-2022, 07:43 PM   #10
Rob Doe
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Default Re: Timing advance

A few further wrinkles to trip up a newbie are: if a previous owner has added an automatic spark advance system under the distributor, where exactly the points open in relation to the spark lever on the column, and as stated above, a higher compression head. It takes a while to learn all this stuff.
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Old 07-28-2022, 11:07 PM   #11
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Default Re: Timing advance

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Originally Posted by Rob Doe View Post
A few further wrinkles to trip up a newbie are: if a previous owner has added an automatic spark advance system under the distributor, where exactly the points open in relation to the spark lever on the column, and as stated above, a higher compression head. It takes a while to learn all this stuff.
Yup! Is there anybody who knows it all? I know, I know, there are plenty who think they do but do they really???
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Old 07-29-2022, 05:56 AM   #12
nkaminar
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Default Re: Timing advance

There is always a new wrinkle. I rode in a car the other day where the owner pulled the spark lever down to start the car and then up all the way to drive the car. It was still too advanced with the lever all the way up. It had one of those advance mechanisms in the valve chamber. I think Alexiskai will know what I am talking about.
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A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
My car grows red hair, and flies through the air.
Driving's a blast, a blast from the past.
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Old 07-29-2022, 09:50 AM   #13
jeepguy1948
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Default Re: Timing advance

So here's my thoughts, first, I will admit that I am new to Model As and as yet have not had mine on the road enough to do this on my Model A but I have 60 years experience with gas (petrol for some of you) and diesel engines. Using a vacuum gauge will answer this question for you, I run a vacuum gauge full time on my engines that have carburetors and it will tell you a great deal. I'm not saying that with one trip down the road you can dial everything perfectly but over a short period of time you will learn what your motor wants. At any given speed you want the highest possible vacuum, it's just that simple. And, with any "typical" gas/petrol motor, it is running at maximum efficiency at 7-8 inches (don't confuse this with tuning at idle, this is with the motor under load, doing what it was built to do). Again, I have not yet had the opportunity to do this on a Model A (hopefully i will soon) but it's worked with the many, many motors I have worked with over the years.
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Old 07-29-2022, 12:28 PM   #14
ETAModel
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Default Re: Timing advance

One thing about the Ford manual and its instructions. When the book was written, late 1920s to early 30s, the majority of roads were dirt, rutted from horse drawn wagons, and terrible by modern standards. So when they said "Average Driving" I'm guessing that was around 20mph. Outside the city most secondary roads were dirt until the late 50s. I read where the new Model A was a likely to be driven at 55 mph as a stock model A is today. I thought that sounded appropriate.
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Old 07-30-2022, 10:57 AM   #15
Chuck Sea/Tac
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Default Re: Timing advance

The whole spark adjustment depends on where the initial timing is set. As well as all the mods, for example, higher compression heads. Possibly even how many times the stock head has been milled. As you all know, first thing that happens when the car won’t start or run right is, re time it!!!
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Old 07-30-2022, 06:10 PM   #16
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Default Re: Timing advance

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Originally Posted by Chuck Sea/Tac View Post
The whole spark adjustment depends on where the initial timing is set. As well as all the mods, for example, higher compression heads. Possibly even how many times the stock head has been milled. As you all know, first thing that happens when the car won’t start or run right is, re time it!!!
Chuck, I don't know if you actually saw it but we both were at a show once and someone actually tried to start his car without the gas or key on. He did set the spark first though. I will never forget the look on his face when he was called on it.
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