Engine wiring question

[1972coronet]

2 hours ago, landman said:

I have a W43

 

I thought that I'd seen a scale version of the 455 Olds Hemi ! Are you planning to install that bad boy into a Cutlass ? The heat crossovers seem to indicate that the engine was darned close to production (cold-start emissions from c.1971) ...

[Lovefordgalaxie]

22 hours ago, Ace-Garageguy said:

 

Here's another excellent point: in the real world, you can put #1 anywhere on the distributor cap, so long as all the rest of the wires are in the correct relationship to it.

This can be helpful in tight engine swaps, for instance, where you might have a big vacuum advance can that causes a clearance issue. Simply roll the engine to TDC firing (not overlap) on #1 cylinder, rotate the distributor to where it physically fits, start wiring with terminal #1 wherever you want it...maybe to take advantage of the lengths of the plug wires you have.

The POINT is, to be correct on a non-factory setup, the #1 position on the cap as shown on the firing-order references is NOT carved in stone.

That fact made learn a lesson the hard way about 15 years ago: Never, ever presume the last guy that did work to a car did things the way you do. 

I never had reason to change the #1 cylinder position on a distributor, so I presumed nobody would do so without a good reason. Wrong!!

15 years ago, give or take a year, my friend Ângelo asked me to install new spark plugs, points, condenser, and plug wires on his 1973 Ford LTD Landau (Brazilian built car) The parts were in good shape, but he wanted new parts installed, as he found a NOS set of spark plugs, spark plug wires, points an condenser, all brand new and in the Ford boxes. 

I had the same parts myself, but I would only install them on my Galaxie when needed. 

Anyways, he was and still is my friend and wanted all those factory correct parts on his babied show car, so I decided to do as he wanted. 

I started by removing the old but still good spark plug wires, then the spark plugs, and finally the points and condenser. 

Changing spark plug wires on a 292 Y-Block is a boring job, as there are 04 spark plug wire brackets that have to be disassembled from the engine. Ângelo had a set of brand new brackets with their respective rubber pieces he bought as a kit from the U.S., I guess Dennis carpenter. I carefully ran the wires trough the rubber locators, placed them in their metal brackets, assembled them on the engine, and attached all plug wires to the distributor with the Nº 1 at the marked spot at the cover. Installed the condenser,  the points, carefully set the gap (at the time I didn't have a distributor analyzer to accurately set things like the dwell, so I didn't pull the distributor from the engine, and followed the 0,45mm indicated on the book as correct points gap), and finished with the spark plugs. 

Well, after all that the car would not start. When a big flame came out of the carburetor, I realized someone had changed the #1 cylinder on the distributor, and the entire ignition order was out. Had to put the #1 cilinder in top dead center on compression stroke, and install the distributor the correct way. After that the car started and I just had to set the correct timing with the strobe gun. Now I always look carefully what has being done to a car before even thinking about taking anything apart. 

[#1 model citizen]

There is plenty of good pics here of spark plug location & even a distributer diagram, but what has always baffled me is how is a magneto wired? 

[landman]

9 hours ago, 1972coronet said:

I thought that I'd seen a scale version of the 455 Olds Hemi ! Are you planning to install that bad boy into a Cutlass ? The heat crossovers seem to indicate that the engine was darned close to production (cold-start emissions from c.1971) ...

No. It is sitting in my engine collection.

[1972coronet]

4 hours ago, landman said:

No. It is sitting in my engine collection.

I recognise your gorgeous GMC 702 cube "Twin-Six" as well ! Another work of art !

[Alix Bernard]

19 hours ago, #1 model citizen said:

There is plenty of good pics here of spark plug location & even a distributer diagram, but what has always baffled me is how is a magneto wired? 

A mag is essentially a distributor that doesn't need a battery. Wired(Secondary) the same as a distributor. Single wire with a switch activates it. On the old time diggers, while being pushed, turn mag on, open fuel valve and hang on.

[#1 model citizen]

4 hours ago, Alix Bernard said:

A mag is essentially a distributor that doesn't need a battery. Wired(Secondary) the same as a distributor. Single wire with a switch activates it. On the old time diggers, while being pushed, turn mag on, open fuel valve and hang on.

Ok. I knew it took the place of the distributor, however the wires don't pug into the top like a distributor. Looks like maybe they all come out of a slot about 1/2 way down the side?

[Force]

How the magnetos are made is different depending on manufacturer , some has a regular distributor cap, some has the plug wires come out of the sides of the magneto and some just under the top, so it's best to look at reference photos for the particular magneto.

As we talk about distributors.
There is a reason why they are placed where they are, the distributor is driven from the camshaft through a sprocket and the distributor drives the oil pump in the engine, so on OE cars the distributors are right above the oil pump.
So most of the Ford engines has the distributor at the front of the engine pointing straight up and the oil pump are under inside the oil sump, Ford Y-block has it at the rear at an angle towards the passenger side and the oil pump is on the outside of the block on the bottom drivers side, the flathead V8 is different as the distributor don't drive the oil pump, the distributor is mounted at the front of the timing cover on the early Flathead V8's and the later 8BA-CM has a angle drive on the upper timing gear and a regular distributor is placed at an angle on the passenger side.
The Mopar big block including 426 Hemi has it in front of the head on the passenger side at an angle and the oil pump is located at the front bottom outside of the driver side of the block.
Buick 66-forward and Cadillac 67-forward OHV has it the opposite way, distributor on the drivers side at an angle and the oil pump outside of the block at the bottom of the passenger side.
Chevy big and small block, Mopar small block and early Hemi, Pontiac, Oldsmobile, Cadillac 49-67 OHV and Buick Nailhead has it straight up at the rear of the engine and the oil pump under inside the sump.
On many modern cars there are no distributors at all, they have coils for each cylinder and the ignition is timed from the computer through sensors on the engine.

Edited December 10, 2017 by Force

[MarvinGardens]

 

And then there is also the Ford 2.3L.............

And then the Folvo.......Ford 2.3L block with the Volvo B234F/R head. Wired just like the Ford 2.3L, as the Volvo has the same firing order/rotation as the Ford.

Edited December 10, 2017 by MarvinGardens

[mr68gts]

8 hours ago, #1 model citizen said:

Ok. I knew it took the place of the distributor, however the wires don't pug into the top like a distributor. Looks like maybe they all come out of a slot about 1/2 way down the side?

What you refer to is a Vertex Magneto. The cap has 8 holes placed in the side of the cap. The wires still go to each terminal, they are just arranged inside the cap with terminals and secured with screws to the terminals inside. Firing orders are still the same as that is determined by the crank and cam cycles. There generally is no coil on a vertex mag but companies offered conversions to run one sperate from the internal generator. Tip, DO NOT rotate a mag in your hand and touch the terminals. Most being self energizing with shock the unholy H. E  double hockey stick out of ya! There are or have been conversion caps for this style of magneto to run normal style external terminal wires.

Edited December 10, 2017 by mr68gts

[#1 model citizen]

Thanks Paul. This is pretty much the way figured they work, although they have always been somewhat of a mystery to me. (Something I should have researched but never have  ) I am really more interested in the way they look in order to convincingly wire a model engine. Your explanation & photo of the cap(?) helps.

Could you maybe provide a photo of the outside of the magneto with wires in place. Maybe a photo of one on a engine? Anyone? Maybe different styles /brands?

Edited December 10, 2017 by #1 model citizen

[426 pack]

51 minutes ago, #1 model citizen said:

Thanks Paul. This is pretty much the way figured they work, although they have always been somewhat of a mystery to me. (Something I should have researched but never have  ) I am really more interested in the way they look in order to convincingly wire a model engine. Your explanation & photo of the cap(?) helps.

Could you maybe provide a photo of the outside of the magneto with wires in place. Maybe a photo of one on a engine? Anyone? Maybe different styles /brands?

Here are some pics of the outside of some magneto 

[426 pack]

I found a pic of this engine. Dose anyone know what it it? It looks like an OHV HEMI but the distributors are in an odd place.

[mike 51]

^^^^^^^
 

It's a (VERY) dressed up WW2 era Ford GAA  a tank engine!   

Edited December 10, 2017 by mike 51

[Mercuryman54]

Boss 429 ford

[#1 model citizen]

6 hours ago, 426 pack said:

Here are some pics of the outside of some magneto 

 

 

Thanks Cale. those are some great pics. Just the type I was hoping for! 

[blunc]

On 12/8/2017 at 8:37 PM, Lovefordgalaxie said:

That fact made learn a lesson the hard way about 15 years ago: Never, ever presume the last guy that did work to a car did things the way you do. 

I never had reason to change the #1 cylinder position on a distributor, so I presumed nobody would do so without a good reason. Wrong!!

15 years ago, give or take a year, my friend Ângelo asked me to install new spark plugs, points, condenser, and plug wires on his 1973 Ford LTD Landau (Brazilian built car) The parts were in good shape, but he wanted new parts installed, as he found a NOS set of spark plugs, spark plug wires, points an condenser, all brand new and in the Ford boxes. 

I had the same parts myself, but I would only install them on my Galaxie when needed. 

Anyways, he was and still is my friend and wanted all those factory correct parts on his babied show car, so I decided to do as he wanted. 

I started by removing the old but still good spark plug wires, then the spark plugs, and finally the points and condenser. 

Changing spark plug wires on a 292 Y-Block is a boring job, as there are 04 spark plug wire brackets that have to be disassembled from the engine. Ângelo had a set of brand new brackets with their respective rubber pieces he bought as a kit from the U.S., I guess Dennis carpenter. I carefully ran the wires trough the rubber locators, placed them in their metal brackets, assembled them on the engine, and attached all plug wires to the distributor with the Nº 1 at the marked spot at the cover. Installed the condenser,  the points, carefully set the gap (at the time I didn't have a distributor analyzer to accurately set things like the dwell, so I didn't pull the distributor from the engine, and followed the 0,45mm indicated on the book as correct points gap), and finished with the spark plugs. 

Well, after all that the car would not start. When a big flame came out of the carburetor, I realized someone had changed the #1 cylinder on the distributor, and the entire ignition order was out. Had to put the #1 cilinder in top dead center on compression stroke, and install the distributor the correct way. After that the car started and I just had to set the correct timing with the strobe gun. Now I always look carefully what has being done to a car before even thinking about taking anything apart. 

technically, you didn't need to pull the distributor, you could have just moved the plug wires in the cap to the correct position once you had #1 cylinder at TDC (been there, done that), it gets a little wacky if you still get backfires after doing that.

[peteski]

And a Ford 289 engine in a 1:43 scale AC Cobra.  The distributor is a bit clunky looking (molded with the intake manifold) - I should have reshaped it, but it is what it is.

[Ace-Garageguy]

On 12/9/2017 at 12:24 AM, #1 model citizen said:

There is plenty of good pics here of spark plug location & even a distributer diagram, but what has always baffled me is how is a magneto wired? 

Here's a lot of info on mags in general, and things that are sometimes mistakenly thought of as mags...

AND SOME GENERAL FUNCTION INFO:

Here is an answer I posted to this exact question on another forum a few months years back. I hope it will clear up some mis-understandings (EDIT: my organization here is poor as a general-knowledge piece, because it was originally posted as several answers to some specific questions; however, read all of it, and you should understand enough of the basics for accurate model-car work).

I've posted this before. I currently build 1:1 period hot rods for a living, and I'm an engineer. This is the true and complete answer from someone with 40 years of actual experience working with magnetos, etc.

A lot of old race cars ran magnetos. If they didn't have onboard batteries (to save weight) they HAD to be push-started.

Mags were / are commonly run on period street / strip cars. They made a fat, hot spark at relatively high RPM before the days of capacitive discharge. A fair number of 'teens and '20s cars came with magnetos, and many early race car mags were adapted from AIRCRAFT parts. Small aircraft engines STILL use magnetos that look very much like those on '40s-'60s competition cars, and they use them because the engine will continue to run even if the rest of the electrical system fails. Small airplanes have batteries for starting, and charging systems ( generator OR alternator ) to run accessories and to keep the batteries charged for starting.

TO RUN A MAG on a street / strip car, you'll need a generator OR alternator, and a battery , and a starter. You will NOT need a coil or distributor, of course. The advantage to using an alternator is that it will provide more current at lower RPM. They work better at running loads like air conditioning and lights at idle, or while sitting in traffic. Alternators began to become common in production cars in the early '60s. They appeared first on police cars because of the high electrical demands of the communications radios. Interestingly, most small aircraft alternators are adapted from CAR parts.

1) The magneto has an internal generator (sort of), points, "coil" (sort of) , and distributor cap, and provides its own spark to fire the plugs

2) A magneto does not provide enough energy to keep a starting battery charged, or to run any accessories

3) For STREET use, battery and starter motor will be required to start the engine. Old race cars (that didn't have batteries or starters for weight-saving) were push started, 'cause the mag has to be spinning to make any juice, and without a battery and starter, no spin, no juice.

4) A charging system will be required ( generator OR alternator ) to keep the battery charged and run accessories.

MAG WIRING OTHER THAN PLUG WIRES: For a push-start car, you only need one small ground wire going from the mag to a kill switch inside the car. The only way to "turn off" a magneto is to ground it. For a battery start, street driven car, you could also simulate a starting-voltage booster with a small hot wire running to the mag. These would be two very small wires, much smaller than plug wires, coming out under the "cap", well away from the plug wires. The small hot wire could run to a little box on the firewall.

There was also a unit called the Spalding Flamethrower, basically two, four-cylinder coil-type ignition systems in a single, usually red, case. It looks like a mag, but isn't. It had two groups of 4 plug wires on either side. Do a google image search for that. It was fairly common on really hot street cars, as was the Vertex ( Scintilla, Joe Hunt, etc.)

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In closing, a mag won't blow out lights as someone posted above, because it's constructed so that it's spark discharge is directed to a SPECIFIC spark plug as the magnetic field collapses, and not into the car's general electrical system.

The spark is created in a magneto when the magnetic field rapidly collapses inducing a high voltage in the adjacent wire windings. The spark is directed to a specific plug by the position of the rotor in the "cap", exactly as it is directed to the correct plug in a battery-type ignition system. A magneto is timed in much the same way as a POINT TYPE battery powered ignition system is timed, to make it fire with the correct amount of ignition "lead".

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A further clarification of the actual function of a magneto vs. a distributor:

An older DISTRIBUTOR does two things. 1) It tells the coil when to fire and 2) it directs the resultant spark to the correct spark plug. (Many later-model distributors ONLY direct the spark to the correct plug and have no role in establishing ignition timing).

It knows when to tell the coil to fire because it has a sensor of some type, either points, a magnetic device, or an optical device, that senses the position of the distributor shaft in relation to the crankshaft (and cam). This is called "ignition timing". It can be varied by manually twisting the distributor body during tuning, or automatically by mechanical or vacuum "advance" mechanisms while the engine is running.

A little wire running from the distributor to the coil carries a signal that makes the coil "fire" (resulting from a collapsing magnetic field inside the coil), and the resultant secondary current, the "spark", is directed back to the distributor by the one BIG wire in the center, and sent to the correct spark plug by the "rotor", which turns with the distributor shaft and aims the "spark" at the correct BIG wire going out.

This is an oversimplification, and I've used some terms loosely, but that's how it all works in a nutshell.

A rotating permanent magnet inside a MAGNETO induces a current in the PRIMARY winding, creating a larger magnetic field (an electromagnet) adjacent to the secondary winding. When the points open (they are connected to the primary winding as a timed-switching-device, and they perform exactly the same function as in the distributor workings described above, namely to tell the magneto the position of the crankshaft and cam) the current stops flowing in the primary winding. The magnetic field collapses, and the moving lines of magnetic flux of the collapsing field induce a much higher voltage in the SECONDARY winding, which is more-or-less analogous to the COIL in a battery system (with a distributor). The hot "spark" output from the secondary winding is directed to the correct plug by a rotor-and-cap and secondary wires, just like in a distributor ignition.

Because the magneto is capable of producing its own primary current AS LONG AS IT IS TURNING it doesn't require a battery or generator or alternator to function, and this, again, is why you always see old mag-equipped race cars either push-started, or started with an external device, like old Indy cars. Because the battery and something to keep it charged (generator or alternator) aren't required to keep a mag-equipped engine RUNNING, there is no onboard battery to run a starter either. SO, the engine in a mag-equipped car THAT HAS NO STARTER has to be made to turn some other way, so the mag can make a spark, by pushing the car in gear, or by an external starter that spins the engine.

But one more time, you CAN have a street-driven car that has a battery to start it (which spins the starter motor), a generator OR alternator to keep the battery charged and run lights and accessories, and a magneto, that does absolutely nothing but fire the spark plugs.

Edited July 2, 2012 by Ace-Garageguy

 

Edited December 11, 2017 by Ace-Garageguy

[Lovefordgalaxie]

8 hours ago, blunc said:

technically, you didn't need to pull the distributor, you could have just moved the plug wires in the cap to the correct position once you had #1 cylinder at TDC (been there, done that), it gets a little wacky if you still get backfires after doing that.

Pulled it, because I wanted to make the #1 to be at the spot marked as #1 on the cap. 

[Greg Myers]

Cloth wires

[Jantrix]

On 12/7/2017 at 2:31 PM, DanR said:

but what if I don’t know exactly what type of engine I’m using in a given model? I’m just starting to flirt with the idea of doing some wiring and I want to make sure I get it right. Thanks!!

Where there are a few kits that have a sort of generic V8 that could be this or that, most kits are pretty good about identifying the engine that is featured. If you don't know for certain what the engine is, post up some photos in the Q&A section and some one here will set you on the right path. After that, Google will show you where your spark plug location are. I'm sure you'll do better than I did on my first attempt. This is the ultra rare 7 cylinder alternate spark plug location hemi. 

[#1 model citizen]

15 hours ago, Ace-Garageguy said:

Here's a lot of info on mags in general, and things that are sometimes mistakenly thought of as mags...

 

 

Thanks Bill! All that is highly informative. Thanks for including links to the older threads, too. I just wish that the pics that are now missing from those threads were still visible 

Edited December 12, 2017 by #1 model citizen

[DanR]

6 hours ago, Jantrix said:

Where there are a few kits that have a sort of generic V8 that could be this or that, most kits are pretty good about identifying the engine that is featured. If you don't know for certain what the engine is, post up some photos in the Q&A section and some one here will set you on the right path. After that, Google will show you where your spark plug location are. I'm sure you'll do better than I did on my first attempt. This is the ultra rare 7 cylinder alternate spark plug location hemi. 

I don't know Rob, I have fat fingers and my eyes aren't as good as they used to be. I just want it look close without having to be perfect!

[peteski]

4 hours ago, #1 model citizen said:

Thanks Bill! All that is highly informative.

Sorry for the rant but I think it is really silly and awkward when people quite an entire lengthy post (with photos) just to say "thank you".   Trimming the quoted message makes the thread easier to read (and less scrolling through duplicate info).