Flathead V8 Distributor Slot in Cam shaft

[Veeder]

Any chance could anyone tell me if looking by looking at the slot in the end of the Cam if I can determine TDC within +- (xx) degrees?

Thks in advance
Bob

[Mart]

I'd say yes, but not to a degree of accuracy that would be helpful for timing.

I've shown it in some of my videos.

This one for example:

https://youtu.be/dn446jjCVRg#t=24m0s

Mart.

[AnthonyG]

What is ur end game? Ie, R u checking cam 4 correct orientation or u want to find top dead center & Mark 4 timing? R ur heads installed?

[Veeder]

Heads are installed I would like to just know if the slot is vertical ita fairly close to top dead center. I'll check out the utube a bit later thk u!!

[Mart]

It's at about 45 degrees.

[JSeery]

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TDC is so easy to determine why not go ahead and mark the crank pulley and install a pointer? Comes in handy later on.

[AnthonyG]

I did what JSeery suggests. To ascertain TDC u really need to remove head & watch the piston to see highest point in stroke, use an indicator for accuracy. Then marked the pulley & made / matched the arrow pointer. I did it while heads were already off to replace Pistons.

[Veeder]

Thks everyone all this inf. Is helpful as always!!!!

[JSeery]

But, it is easy to do with the heads on.

[Veeder]

Hey guys
I wanted to answer Nomad as he asked a very good question "what is ur end game"

I was not 100% sure my brother and I would be successful therefore it might have been a bit premature to answer his question at the time. My brother (Seattle) me (CT) decided we could take a stab at designing a distributor tester which could verify point settings to establish both Dwell and Dwell angle on Flathead v8 distributor (It should also be-able to determine the advance mechanism is basically functioning and I believe we can without much effort as I can already tell in the graphs when the mechanical advance is adjusted.

SO about a mth ago he and I started learning about Stepper motors, Microcomputers, Micro-controllers and misc sensors to design something that could do some quick tests and assist in setting the points. Within the last couple of days we feel we have been successful. The design still needs some work but I now feel confident that when I set the points I can be certain they are in an acceptable range for establishing Dwell and Dwell angle.

The next question is WHY - Well I've lived through a whole bunch of issues (Drama)with the car and always getting towed home and I was always blaming the distributor/coil. Thanks to the help of folks like Skip Haney and others I got this behind me but don't ever want to go through it again. I also didn't want to spend a bunch of money of a timing fixture which I could not justify. Hence lets see what we can do. If we manage to get this to the next level the fixture should beable to be made on a 3D printer, stepper moter ,controller small power supple (optional 12 v battery would work) Audrino (micro-controller) you could build this for under $150 however its not quite ready to be what I'll call idiot proof. We don't need people burning up boards like I managed to LOL

My brother and I have come up with a design and software that at some point we will give it to folks as there is no intention to make any $$ on this but what we have now is a working prototype. I still may add a second sensor on the tester as a reference for TDC #1 on the distributor but working on setting the exact position was the reason for the post initially. I need to mark a distributor with exact TDC #1 so that if a ref. sensor is built in it is located exactly in the right place on the tester. Therefore in this situation I need a couple of marks on the dstributor itself vs the crank pulley.

We been able to generate some cool graphs of the timing and point activity.

"What is ur end game? Ie, R u checking cam 4 correct orientation or u want to find top dead center & Mark 4 timing? R ur heads installed?"

Anyways as always thanks for the help folks have given me on issues like this in the past and an fun winter project

bob
_______________

[Lawson Cox]

Originally Posted by AnthonyG

What is ur end game? Ie, R u checking cam 4 correct orientation or u want to find top dead center & Mark 4 timing? R ur heads installed?

Is it really easier for you to figure out shorthand to write a note? Well, it is not easier to read on this end. It doesn't really save any time in typing, and in fact, you have to stop and figure out your abbreviations yourself so it is counter productive to deviate from the norm. Not bitching, just trying to learn all this new jargon and the reasons behind it.

[tubman]

I gotta agree with Lawson on this.

[koates]

Originally Posted by AnthonyG

I did what JSeery suggests. To ascertain TDC u really need to remove head & watch the piston to see highest point in stroke, use an indicator for accuracy. Then marked the pulley & made / matched the arrow pointer. I did it while heads were already off to replace Pistons.

Hi Anthony, I agree with what Lawson Cox has posted but I will have a bitch as well. As many of us old guys dont text much or at all, it would be appreciated if you could just type in normal plain English on this forum so that we can easily understand you. Buggering up the Queens English is not ok with me. Regards, Kevin.

[Ronnie]

Originally Posted by tubman

i gotta agree with lawson on this.

x 2 ^


r

[Veeder]

Ok I understand

[Zeke3]

Veeder, it does sound like a fun Winter project. I look forward to seeing the results of you and your brother's efforts.

I too would like to have an old distributor tester, but cannot justify the expense or the space to store such a device, but it would be fun to have one.

[deuce_roadster]

Sounds like you are re inventing the Sun Machine.

On a related note, I have a friend who actually installed the distributor 180 degrees out without breaking anything. There apparently was enough wear in either or both the cam slot and the distributor tang to do this and of course the engine wouldn't run but it sure did backfire.
My added question to this is how do you account for wear/play in the distributor to cam slop in an engine that is all together?

[Veeder]

Wow it's best to think of this as similar to a churchhill machine however there is very little reason that this could not be similar to a Sun.
Still very early in the process but the data appears very precise and repeatable in all likelihood looking at the graphs you could red flag distributor lobe wear

[hubercats]

Veeder's brother here: As regards our reinventing a Sun distributor test machine, that really hasn't been our goal. Our goal was/is to build a machine that allows us to do initial setup of a newly rebuilt distributor, for example. By this I mean setting the gaps of both sets of points and determining when the points open with respect to the top-dead-center (TDC) of cylinder 1 (compression stroke). Our system rotates very slowly (about 7 RPM) by intention so we cannot assess things like points floating at high rpm, things that a Sun machine is capable of doing. However, based on our preliminary results it seems we are able to set the point gaps accurately and verify static timing. Also, as a side benefit, we can assess the "health" of the distributor lobes. So, for instance, if one of the lobes happened to be flattened, for whatever reason, it would be immediately visible in our plots. Finally, we built our prototype system for less than $100 in parts and the time that Veeder and I spent on software development and construction of the test jig. All in all, it's been a fun project for us and if our work can benefit others we're happy to share our ideas. Lastly, there's the cost of a "real" Sun distributor testing machine ... ;-)

[Veeder]

here is a pic of the prototype for those that might like to see it. Yes more work is needed but consider this a cardboard working model.
20210216_135626c.jpg

[Mart]

That's an interesting looking setup. I would be interested in seeing it working.

Have you seen or used a krw timing fixture?

I have a really nice quality Churchill unit here in the UK. I did show it in some of my earlier videos.

Mart.

[35fordtn]

I think a Sun Machine has a benefit due to spinning at speed to observe sticking weights, advance curve, point float etc etc. The only thing I could see a Software set up being able to do that a Sun Machine cannot is to stack graphs from all eight cylinders and overserve differences in dwell for each cam lobe.. ... Essentially what you have stated above. You will need a better way of holding a distributor accurately as the casting flaws will change the way it sits the way you have it clamped to a table. I would recommend bolting a timing cover to the fixture so that you could attach the distributor to the Timing cover. Essentially you are more closely replicating (in digital form) what a later KRW fixture does rather than a Sun Machine.

[Veeder]

Mart

First thank you for the videos I know they must me time consuming in fact I was looking at yours to attempt to get a sense of cam position and the angle of the slot relative to TDC of #1 compression stroke. I don't have an engine torn apart to look at this and wanted to mark a distributor body with that position.

have never used a Sun Machine or any one of the other units such as the Churchill or KW. They are a bit out of my price range. We have already changed a couple of things and are making a couple more modifications.

The attached document will be just a quick example of the data plotted. We have (my brother and I ) have plotted plots with zero mechanical advance and +/- advance curves which we found very interesting. For example we can see in the charts looking closely the interaction of the overlap of the set of points.

What is really nice is it allows you to step precisely to an area on the distributor lobe and set points.

We have more work to do on it but our initial objective was met.

Bob







bob

[Lawrie]

Great work,
I made my own distributor tester, brother in-law is an electrical guru who made his own electric motor bikes he is smart,
he made me the circuit board to drive the electric motor that drives the distributor, up to about 4ooo eng rpm,
I have a strobe and can map out the advance curves and set up the vac brake as per the service manuals,
It sure makes you realise there are good ignition points and BAD ones.
Let me know if you want some picks and info.
Lawrie

[Lawrie]

The only thing that I would like on my machine is some stuff ( software) that would map out the advance automatically ,rather than me physically do it ,
But as 35fordtn says ,it sure picks up advance units, sticking ,and not right.
Lawrie

[hubercats]

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Veeder's brother here: A quick note on the plot that Veeder posted. The blue ramps are from the Hall Effect angle sensor. Because of the way the sensor mounts to the stepper motor shaft, the angle reduces as the distributor moves forward (i.e., in the proper direction). We'll fix our software in the next revision to make the angles increase with time as that seems a bit more intuitive. The orange curves show the points opening/closing. The point opening/closing data are scaled to fit between 90 and 270 degrees (y axis) so they are visible on the same plot as the ramps which go between 0 and 360 degrees. In this particular test, we set the timing such that the number 1 cylinder points open at 0 degrees top-dead-center for cylinder 1 (compression stroke). We know this is not the proper setting. We did it to verify the calibration of the angle sensor and point open/close sensor.


The points are open for about 10 degrees out of every 45 degrees, implying that the dwell angle is about 35 degrees. The regularity of the point openings also shows that the the distributor cam lobes are uniform.


I've seen a few posts suggesting that a higher rpm capability would be nice. We have considered this and may make a variant of the system for that purpose. For now the stepper motor speed limits us to rather low rpm, but low rpm is perfect for assessing the main things we have been interested in thus far. A dc motor, perhaps geared, would allow for much higher rpm, but at the expense of angular control; at least using simple, inexpensive motors and motor control components. Veeder, who has the car with the flathead in it, does not intend to race it so floating points is not one of his primary concerns.

[AnthonyG]

As u ask I’ll answer! Hope u have a sense of humor! New world, new tech. Ur right, it is txt type! Im 71 & like it. fewer key strokes! Don’t have to think about it at all as I txt more than I talk on the phone! More efficient! Sorry it confused u, . I do understand, some old dogs & new tricks! Sounds like Veeder understood.
Again sorry & Best 2 all, especially 2 any who it bothered!
AG

[ford38v8]

Originally Posted by Ronnie

x 2 ^

r

So, Ronnie, as you agree with Lawson, I take it that you intend to stop abusing the King’s English at some future time?

[AnthonyG]

Hi JSeery, I don’t think anyone asked so guessing I’m the only one in the dark . What’s the easy way to find & Mark pulley for TDC without removing the head?

[Mart]

Anthony. It's the cable tie method.

I illustrate in in this video:

https://youtu.be/dn446jjCVRg

Mart.

[AnthonyG]

Thx Mart!

[hubercats]

I've seen some comments on the internet where people are questioning the accuracy of finding top dead center using methods such as the cable tie approach on account of the fact that the crankshaft in flathead engines is offset from the center of the engine. While I can see how this introduces some error, my gut instinct is that the error is quite small, probably a degree or two at most. If anyone knows of the magnitude of this error, it would be interesting to know the number.

[JSeery]

Originally Posted by hubercats

I've seen some comments on the internet where people are questioning the accuracy of finding top dead center using methods such as the cable tie approach on account of the fact that the crankshaft in flathead engines is offset from the center of the engine. While I can see how this introduces some error, my gut instinct is that the error is quite small, probably a degree or two at most. If anyone knows of the magnitude of this error, it would be interesting to know the number.

Sounds like BS to me, TDC has nothing to do with crankshaft offset. TDC is TDC it is where the piston is at the top of it's travel. Using a dead stop with the heads on is as accurate as the person doing it. If it is repeated several times to eliminate/decrease any error, it is very accurate.

[hubercats]

I agree that TDC is TDC. That doesn't mean that the method for estimating TDC (with the heads on the engine) is necessarily perfect. So that people can judge for themselves, here is the web page where this subject is discussed: http://www.mapleleafup.net/forums/sh...ad.php?t=21652

[AnthonyG]

It seems pretty obvious you have to ascertain which method makes sense for the set of circumstances! If as I was in a project where head removal was required for something else anyway, the heads off method makes sense. If u simply have or acquired an engine w/o a timing arrow or marked crank pulley was the only issue with no need to remove heads then the tywrap method looks like a great way to go & as JSeery & Mart indicate as easy as it is do it several times to get a good feel & see where the marks end up & You’ll
get a TDC Mark that’s pretty damn accurate!

[Mart]

Hubercats. The people questioning it are right. The crank offset will have an effect. However, at the distance down the bore that we are talking about, approximately 1/4", the effect is so minimal as to be negligible. It is far less, for instance than your ability to accurately make the marks and locate the centre point of those marks by eye using hand tools.
It is far more accurate, for instance than using a test indicator to clock TDC and trying to work out exactly where TDC occurs in the dead band at TDC.
In other words the solid stop method is good enough.
Mart.

[glennpm]

I agree with Mart and Seery on the solid stop method being very accurate and suitable for most. An all out racer may want a "heads off" determination but for most, the solid stop method is very accurate.



For the zip tie, just keep the tie in the same location which doesn't have to be at the top of the piston; for the rotation up to the solid stop and then back in the other rotation, splitting the difference for TDC (Top Dead Center :-))

[Veeder]

Very helpful information guys thank you as always!!
Bob

[hubercats]

Thanks, Mart. I wasn’t questioning the utility of the tie wrap method. Rather I was just noting that it had been a topic of discussion in the Australian forum. I’m a big fan of “good enough for the job” approaches and the method you so nicely describe in your YouTube video (thanks for making and sharing it) is a method I would use myself - if only I had a flathead of my own. As it is, I’m enjoying these discussions as a side effect of working on the distributor test rig with my brother (Veeder) - vicarious fun. - Cheers!

[Veeder]

Another question
Since we are setting the mechanical advance to zero degrees and we know withing 1 degree or less TDC. Why can't I just set the points (Driver-side) to just be opening at o degrees and then set the second set of points to open at 11 degrees. Ideally I don't want to be isolating the two sets of points. My assumption is the correct overlap of the point activity is going to happen by default.

Also once that's done you can set the mechanical advance.

Correct?
bob

[Mart]

Bob, Jim, check this thread. It may or may not point you in the right direction.

Or google points setting flathead v8 by two ruler method

https://www.fordbarn.com/forum/showthread.php?t=126536

Mart.

[Veeder]

Thank you Mart

Is good information

I've been on the Vanderbilt website multiple times and am familiar with the two ruler method but this is the first time I've ever seen that adapter for using on the 3 bolt 11A distributor.

Bob

[Lawrie]

Pic of my home made tester, use it most every week.
Lawrie

[Veeder]

WOW very cool! The fact that it checks the coil with real sparkplugs is the perfect tester. Just keep your voltmeter aw a y from the coil both l9w voltage and high.

If you could sometime when you next using itwould you mind after it has rote a few times bring the rotor around and observe the number one plug at TDC. Based on what I've been told it should be perfectly
Even with the pin on the cap. #1.

Have a great day and thanks
Bob

[hubercats]

Very impressive setup!

[Mart]

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Originally Posted by Veeder

WOW very cool! The fact that it checks the coil with real sparkplugs is the perfect tester. Just keep your voltmeter aw a y from the coil both l9w voltage and high.

If you could sometime when you next using itwould you mind after it has rote a few times bring the rotor around and observe the number one plug at TDC. Based on what I've been told it should be perfectly
Even with the pin on the cap. #1.

Have a great day and thanks
Bob

Veeder, are you sort of stating the obvious?

When firing on No1 plug the rotor arm HAS to be pointing at No1 terminal.

Using this backwards to state that when pointing at the terminal the piston must be at TDC is technically correct but not an accurate way to determine TDC.

Or have I misunderstood what you are saying?

Not trying to be negative, just trying to avoid misconceptions.

Mart.