TheSamba.com :: View topic

Fri Jan 28, 2022 4:15 pm

In an effort to reduce the dilution on Jeff’s MSD distributor tips and tricks thread I will start a Magneto thread.

I ran a locked out Vertex on my Turbo drag bug back in the late 80”s early 90”s
It was locked out with timing at about 24 degrees, it never missed a beat.

Now I have a rebuilt Mag from a Swiss industrial 25 HP engine, that was basically never run, It had no spark at all when I first tested it. I sent it to Don Zig about 5 years ago, it took him 2 years to get it back to me :shock:
But it now works perfect. Apparently it was upgraded with all the best parts including rare earth magnets., I have not taken it apart so I dont know for sure. I will be tweaking the advance curve at some point, when I do I will be sure to document the process.

There are Pros and Cons to Magnetos and we can dive into all of that as this thread progresses. 😬

I will start off the information here with a terrific article written a few years back. I did reach out to the author to find out when part 2 will happen, he said it was still in the plans but not holding my breath. it’s a great article you are interested in the history of the Magnetos.

https://www.streetmusclemag.com/tech-stories/elect...x-magneto/

Fri Jan 28, 2022 8:45 pm

Joe Hunt Vertex with a Bosch 010 advance curve i purchased new back in 1981, paid a small fortune for it.

I was working the counter at the Auto Haus store in Van Nuys at the time, had it delivered to the store COD.

It hasn’t be run since 1982 so it’s due for a freshening.

Sat Jan 29, 2022 8:43 am

I went through a few Hunt and Fairbanks Morse back in the day that were run on Harleys.
My only work to them was the basic mechanical overhaul stuff like bearings, points, condenser, cap, etc.

Put your finger on one of the plug wire terminals, spin the mag just a bit, and it will bite.
Great fun at biker parties...

One thing a few people mentioned was that over time you need to get it "polarized".
This was supposedly regularly done on aircraft and going to the local airpark you would find people doing it easily.
Was said that you can have it done with the mag fully assembled?

There's also supposedly an old man who used a magnet as big as a tree stump to polarize mags but that was probably one of those stories.

Not sure if any of this is true, but if so an old mag that's been sitting for years would likely need this work done.
Other than that, there's no mysterious parts inside of these.
Open one up and you see a coil, points, condenser, etc. just like a regular battery ignition.

Sat Jan 29, 2022 9:33 am

Here is my mag. I am going to send it off to Joe Hunt for a rebuild. I am going to go with the "010" curve. It is set a 0*, should I get it locked out to 20*? What are the advantages to this? I have Taylor wires and the Autometer tach signal converter. What else do I need? I want to use my ignition switch to start the car, so I am going to buy the relay from Hunt. Do I need the buzzer box to time it or can I just drop it in and time it like regular old distributor with a timing light? I want a black cap, but was told there are no caps but they are coming.

Sat Jan 29, 2022 4:33 pm

Damn, Darren why do you engines always look so good.

I remember Jim Ratto telling a story about Jerry at the Buggy House installing one on Jim's engine. I think it was a Hunt magneto locked out back in the day and it made his mismatched engine at the time run like a bat out of hell.

Sat Jan 29, 2022 4:50 pm

Very curios about the reasoning of using a magneto on a engine that has power generating capability. Isn't the point of having a mag instead of a dizzy that you don't even need a battery?

Sat Jan 29, 2022 4:55 pm

on our vw dragster we ran a vertex mag for 20 years .it never let use down . we bought all the best MSD parts and put the MSD on the the dragster.motor the dragster ran the same times as the vertex mag .the good thing i can say about the MSD the motor started faster . to me the MSD was a waist of $750.00.. we had no alt. to charge he batt. so after two runs the MSD drained the batt. we put the vertex back of the motor . . i sold the MSD i must say one thing about MSD it made my 1964 gto with try power carbs run faster . i liked it on the GTO spencerfvee

Sun Jan 30, 2022 9:22 am

bsairhead wrote: Very curios about the reasoning of using a magneto on a engine that has power generating capability. Isn't the point of having a mag instead of a dizzy that you don't even need a battery?
I originally purchased mine when I was drag racing an 1835 without a generator or any cooling tin. I wanted to save my battery charge for starting the engine and running gauges.

Now I might run my magneto on a hot street 1835 that sees mostly short jaunts around town. Just because I like the way it looks for the most part.

Sun Jan 30, 2022 3:31 pm

one thing about a magneto is the faster you turn it, the hotter the spark. I used to run a test stand on aircraft mags and at 2500 RPM (on the mag shaft) you could jump an inch long air gap. there is a special machine to re-charge the magnets but I know a guy that used to do it on a DC Magnflux machine. the gauss can be read with a meter or the special tool. the one we had didn't have a scale, only a "good/recharge" line. it was old as the hills then and that was nearly 30 years ago. I don't remember seeing one that needed re-charge except for really old ones... like 50 year old

Mon Jan 31, 2022 3:36 am

Some info om the Scintilla magnetos used on vw industrial engines.

They all had weights and mechanical advance. This is the 4 late Scintilla magnetos used. The difference ..010 vs ..001 and ..017 vs ..006 is that the latter ones are fully shielded (often on equipment used by the military).

Test values plotted and compared to the "010" distributor also used on late industrial engines.

Earlier magnetos had a different curve. This is from the 25HP industrial engine workshop manual. They used the "383" distributor or the OAP 4 L 402 Z 144 magneto. Both were set @5* BTDC so the test values in the pictures should be -5* to get the advance from the distributor/magneto and for comparison with the later magnetos:
850rpm - 5-7*
1500rpm - 11-16*
3000rpm - 29-32*

The rpm limiter in the magneto works with centrifugal force, making a bracket fling up and short out the rotor tip. In the max setting this happens around 4000rpm (2000 rpm on magneto shaft) and this the "/1950" on the data plate in the picture below (shorts out at 1950rpm = 3900rpm engine).

However it could be set to a lower rpm by the vw factory and this was then stamped on the plate. In the above plate "16,5" means that the rpm limiter was set to 16.5 x100= 1650rpm magneto = 3300rpm engine.

The setting can be altered though or the bracket removed completly.

Schematic view of the Scintilla:

The working of the weights:

Lubrication Scheme:

Non shielded to the left and 2 shielded Scintillas to the right (the middle one is earlier).

Mon Jan 31, 2022 7:54 pm

Thanks Frederic, I have a Vertex service manual that I will scan to PDF when I have a chance.

Cheers.

Mon Jan 31, 2022 8:11 pm

VeloMikey wrote: Here is my mag. I am going to send it off to Joe Hunt for a rebuild. I am going to go with the "010" curve. It is set a 0*, should I get it locked out to 20*? What are the advantages to this? I have Taylor wires and the Autometer tach signal converter. What else do I need? I want to use my ignition switch to start the car, so I am going to buy the relay from Hunt. Do I need the buzzer box to time it or can I just drop it in and time it like regular old distributor with a timing light? I want a black cap, but was told there are no caps but they are coming.

You want a curve on the street, The turbu guys lock it out so under boost its not at 31 degree and hurting the engine, timing is power and topping your N/A car off at 24 won't work well for power.

I time with a normal timing light, works fine.

Mon Jan 31, 2022 8:38 pm

Iset my Magneto timing with a single wire regular ol timing light, then checked it with a Buzz box, Results were the same.

Tue Feb 01, 2022 8:15 pm

Tachometer or Rev Limiters with Magnetos

Vertex style Magnetos with internal coils will not work with you regular old Auto Meter or Sun Tach without the use of a Tach signal adapter,
Joe Hunt makes a small wire in adapter, Auto Meter also sell a part number 9118 signal converter box however these are designed for external coil Magnetos.

There are Magneto ready Tachometers available, perhaps you are lucky enough to find a used one on Ebay or fork out some big bucks for a STACK tachometer that is magneto ready....

For RPM limiters Auto Meter makes a Pro Control, I tried one of these and it was a very harsh rev limiter.

By far the best option is from ETC rev limiters, Hank Iden still makes these by hand in the good ol USA. And they work great, He has a lot of options,
A tach output option is available as well so you can connect up pretty much any tach.

Here is a picture of my ETC limiter back from when he was called Wyotech
Probably changed the name to ETC because of the technical school of the same name. ( the box is about 2”x4” or a little less actually...)

Fri Feb 25, 2022 4:51 pm

Another great ignition thread...

Some really informative posts

Look forward to seeing some servicing/rebuild info if anyone has some..

This thread-

http://www.fbekholden.com/forum/viewtopic.php?t=20727

Is from another car forum but contains a lot of good vertex magneto info... history/diagrams/old magazine articles etc..

Also some interesting stuff on dual point dissys and pertronix "dwell" remarkably!

Fri Mar 18, 2022 10:55 pm

I don't read German. Can the scintella rpm limiter be changed for more rpm?

Sat Mar 19, 2022 3:22 am

vwfye wrote: I don't read German. Can the scintella rpm limiter be changed for more rpm?

yes...

but 95% chance it wont suit what youre doing..

check out the link in my last post.

Sat Mar 19, 2022 5:05 am

The RPM limit can be set up to 3600-4000RPM above that and the limit has to be removed or locked

1) weight
2) spring
3) adjustment
4) shorting arm. At the set spring force the centrifugal force/weight at a given RPM lift the arm and shorts the rotor tip. Remove the the arm (weight and spring) and it will not limit the RPM or simply cut the arm off.

Sat Mar 19, 2022 8:05 am

Thank you.

Sat Mar 19, 2022 12:24 pm

I have a Vertex Magneto with the stamped part number 97130 that does not seem to have any advance, it feels locked out. Is there any way to cross reference this number to any known specification or is this number not a "model number", more like the number this particular unit has?