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Rules for setting timing as you drive?

Posted: Tue May 28, 2019 6:57 am
by It's Bill
I just read the topic about high compression heads, and Hank in Tin-a-see mentions these rules. Could someone please educate me on this? Cheers, Bill

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 8:45 am
by Steve Jelf
SPARK LEVER 2.jpg
I believe this widely circulated chart, with one addition here, is from Murray Fahnestock. One experienced T guy I know scoffs at it. He says you should set timing to where it sounds best and forget the chart. I guess my question about that would be what's the definition of "sounds best"?

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 8:51 am
by Tiger Tim
If you’re running on mag, are there more than two timings available anyways?

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 8:59 am
by Tom Hicks
Steve Jelf wrote:
Tue May 28, 2019 8:45 am

I believe this widely circulated chart, with one addition here, is from Murray Fahnestock. [/size]
I would like to read that chart, but it comes up fuzzy on my computer. Can you give a link to it?

Thanks

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 9:09 am
by TWrenn
I was taught by an engine expert that when you pull down the spark lever, do so only until the engine smooths out, and it also usually speeds up just a bit. Anything further is advancing the timing too much and not good. I do that, and like Steve's advisor said, I pretty much "set it and forget it".

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 9:17 am
by John kuehn
I have seen this chart many times and after looking at it and driving my T’s over the years I have come to the conclusion that all T’s aren’t exactly the same as far as these levers settings are concerned. Close but not quite.
I think that some folks think the settings have to be exactly this way. Not necessarily so.
They give you a general idea and after time you develope your own lever settings for your paticular car.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 10:24 am
by John Codman
I'll go with the set it where it sounds best and forgeddaboudit. I'll also go with Ron Patterson's advice to have the spark lever a couple of notches down when you start the car. My '27 will not start with the spark fully retarded.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 10:48 am
by Jugster
Driving a Model T in traffic is very demanding of your concentration. More important than operating the car with perfect technique to achieve perfect smoothness and efficiency is situational awareness. Unless you're one of the few lucky ones who exclusively drive their Brass-Era cars on idyllic country roads shared only by the occasional horse and wagon, you need to concentrate on the cars, tractor-trailers, busses, dump-trucks and young, hat-backwards moron-piloted "tuners" which create serious traffic hazards to an ancient vehicle with all the vulnerability of a motorcycle and none of the bike's ability to brake and accelerate hard and maneuver out of tight situations like a jackrabbit.

I'm not saying you shouldn't be familiar with the chart in the manual. Sure, that kind of knowledge is a good thing, but anytime you're driving a Model T Ford or, for that matter, any Brass-Era horseless carriage with skinny, anti-traction tires and brakes like the Titanic, you need to be on Red Alert the whole time, keep your head on a swivel and be ready to react early—because your window of useful response time is pretty darned small. Every yellow traffic light is an venturesome exercise in judging time, space and speed. Concentrate on that!—'cause you sure as hell don't want to get T-boned in a Model T.

Look, we don't have air-bags, energy-absorbing steering columns, crumple-zones or even bumpers. All we have to keep us out of serious trouble is vigilance. Put your attention where it counts, using your eyes AND your ears, and don't split your concentration between that and fiddling with the spark lever. Find its general sweet spot, set it and there leave it alone.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 11:30 am
by Tom Hicks
I was reading about the E Timer and I think it said that the E Timer automatically adjusts the timing as you drive. For heavy traffic that would be a good situation and it would things a lot easier.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 11:47 am
by Norman Kling
A few things I would like to add.
When you are running on a battery or distributor the timing lever advances the spark with every notch of movement. In that case it is best to time the engine correctly so that it will start with the lever all the way up. Pulling it down just a little on battery could cause the engine to kick and break the starter or your arm.

When you are running on magneto, you will find the spark lever can be moved a few notches without any change in the engine speed and then one more notch and the engine will speed up. Then move a few notches more and no change. Next notch it speeds up again. I call those points "nodes" You can have either 3 or 4 nodes of spark advance. Depending on the combination of the year car, the type timer and the position set for maximum retard when you adjust the timing rod. When running on magneto, it is best to run in the middle of the node, not right on the cusp. The reason is that if there is a slight difference in the adjustment of each coil, you could find one coil sparking on one node and another on the other node, which will make the engine run rough. So find the point where you are in the middle of a node, and try to set the spark lever there. When you advance it find the middle of the next node etc.

If you like to advance the spark a couple notches when you crank start, get the engine running first and then retard the spark all the way. Then advance a notch at a time till you find the point where it speeds up. Notice how many notches it is from fully retarded and do not advance it more than that amount when you try to crank start. Notice that if you change the timer or adjust the timing rod you should find the spot again. The whole idea is to find the center of the node so you will have the most even running ignition for starting. It should not be necessary to do this when starting on battery if the timing is set correctly.
Norm

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 12:34 pm
by Dan B
Tiger Tim wrote:
Tue May 28, 2019 8:51 am
If you’re running on mag, are there more than two timings available anyways?
There are 3.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 12:39 pm
by Mark Gregush
First off there are no hard and fast rules. 2ed, the illustration shown above might be great for the pre 1915 cars, the notches are further apart then the later pressed steel. So 2 notches, for example, on the pressed steel type would not be the same. Also, most of this could be moot using a different timer or not setting the measurements or use of the timing gauge as Ford intended.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 1:24 pm
by Ruxstel24
I'm running a a Thomas distributor.
I have it starting and idling smooth with the spark up. About 8 o'clock is generally where it still idles smooth and runs good. I generally leave it alone other than a big hill I may retard it to about 9 o'clock.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 1:28 pm
by Steve Jelf
I remembered correctly about the chart being from Murray Fahnestock. The copy I posted is unreadable because it was resized for the old forum, so I made a better one. This one is not great, but it's readable, at least on my screen.

SPARK-THROTTLE DIAGRAM.jpg
As there are just three spark positions on MAG, the chart has to be for driving on BAT. The only time I drive on battery is when I have a senior moment and forget to switch over, so the diagram is irrelevant to most of my driving. Add the variation among different carburetors, and it becomes even more so.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 1:32 pm
by Susanne
Running a timer and the stock Mag gives you 3 settings - Slightly retarded, somewhat advanced, and way advanced. If you listen you can hear how your motor changes when its running and you move the spark lever.

Battery (or with a dizzy) you get a lot more variation in your timing.

But it's mainly a sense of feel and sound, if your engine is too retarded, you hear it labor (and feel it heat up), if it's too advanced, you get a distinctive pre-ignition knock. You can scoff at that chart, but it's not a bad guide while you're learning what *your* car likes.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 5:08 pm
by Kerry
Set and forget :D Our lowest octane fuel is about the same as your highest octane in the USA.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 5:49 pm
by Erik Johnson
The chart that Steve Jelf posted above comes from the various editions of the Victor Page book The Model T Ford Car, Its Construction, Operation and Repai.

Copies are available for free download on Google Books - here is one example:

https://books.google.com/books?id=70mJe ... rd&f=false

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 7:48 pm
by George House
OK. I read all the descriptions of the spark and gas levers for the various T driving/idling conditions. And I only take issue with the bottom right illustration: Hill Climbing In High Gear...
After over 50 years of Model T driving in dozens of T s, I have never achieved greater high gear hill climbing capability by RETARDING THE SPARK! What say ya’ll?

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 8:49 pm
by SurfCityGene
Norm Kling has it dead nuts ON!! If you didn't read his first paragraph then you'll have a better running T after reading it if you use the knowledge he wrote.

Today I learned from a test drive how much the RPM affects exactly where that sweet spot is! Yes, you can set it and forget it and a Model T will putt along OK but having that spark lever set exactly in the center of that node makes a difference to a good ear.

My thought is guys that want to set and forget should be the ones that use the famed ETimer since it has the automatic adjusting mode so the spark is offered at the exact perfect timer varying with the rpm.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 8:52 pm
by Ruxstel24
I agree George...
If the RPM gets low enough, maybe slightly retard the timing, but not like the picture shows. Just enough to keep from spark knock.

Re: Rules for setting timing as you drive?

Posted: Tue May 28, 2019 11:01 pm
by Burger in Spokane
I got lernt up on how to drive a T by the crew at the Antique Auto Ranch. These are
the same guys who run in the Montana 500 and many have more years driving T's than
I have been alive. What was stressed to me is that no two T's run exactly the same,
and it is incumbent upon the driver/owner to learn the feel and personality of the T
being driven, with a focus on this magic "sweet spot" others have mentioned. It is when
we develop that "sixth sense" feel, much like we learn how to ride a bicycle or drive a
stick transmission, ... we just sense it/do it without thinking, that this question of
throttle and spark lever positions just sort of "happens" because you feel the speed,
load, hill, etc. needs a little adjusting to the levers to keep the engine humming along
on that "sweet spot".

This may not sound like much help, because it does not point to a clear and defined
answer. But as the guys that taught me said, no two cars are the same and there is no
clear answer. You just drive it, pay attention to how the car responds to various driving
conditions and adjustments, and soon enough it will just come without thinking.