I'm sure this question has been answered many time over, but would like to know if there is a way to check the strength of the magnets before I put everything back together and reinstall the engine... Don't want to have a do-over!
Appreciate the advice.
If its apart, either get hold of a gauss meter and test them, or use a cast iron piston or similar... and see if the magnet ends will hold the weight.
Hope that came across clearly, but if not, someone here will know what I mean,
I didn't have a cast iron piston for a test weight at the time, so I used a spindle which weighs about the same.
Mike, you may or may not know the last time the magnets were charged. If you do know and it was say less than 5 years, you would probably be safe to run them. If you don't know when they were last charged, this is an excellent time to have them re-charged. If you don't know the history of your magnets, some may be cracked and will need to be replaced. Setting up the magneto is time consuming, but fresh magnets, a good coil ring, and a magneto with high output is very nice to have. You sure don't want to have to pull the engine again just to get the magneto functioning properly.
I just read that web page.. brilliant pictures and explanations. Now, what I want to know is...
Does it start on mag now???
I made an electro magnet as well, but yours is about twice as thick as mine. I used a DC inverter welder set at 50 amps... I could zap about 3 magnet ends before I had to stop, freezer the electromagnet and continue... Hot
Had fun, and in the end, they all held the piston. I've heard of guys getting 4-5 lbs on a magnet, but I was not so lucky.
I estimate around 2 weeks before I can test my work..
Any of yous guys fishermens? Dan
Justin, I don't know if it's going to start on magneto. I haven't driven the car since the engine/transmission rebuild, so it's not broken in yet. (Still need to rebuild & install the rear axle.) Just starting it up as it sits, I've had to use BAT. Once it's been driven some, maybe MAG will do it.
I have 7 T's all of them have had rebuilt coil rings, fully recharged magnets, end play to spec and proper timing. Four start on mag and the other three never. I have tired everything to get the last 3 to start on mag with no success. That said, I start on battery with all 7 cars as it is easier for me with a bad back.
This little device will measure your magnet strength and costs about $85.
It is the cheapest one I have found.
The website is at http://gravitastech.weebly.com/ with more information.
I have measured many magnets in an attempt to determine how many Gauss will be required to lift a 2 pound weight.
The only thing I have discovered for sure is that a magnet that lifts a 2 pound weight has a minimum charge for Magneto operation and a much higher charge is possible.
The exact Gauss reading to equate to a two pound weight lift is also elusive and dependent on how much contact the magnet actually has with the weight.
My first calculations were that about 275 Gauss would lift the two pound weight.
If the magnet ends are filed or ground flat for a greater contact area, the Gauss number is much lower and even lower yet if both the magnet and weight surfaces are polished.
Then I found that the highest reading is not at the center of the magnet end, but at the edge areas.
This is also true of the magnet clamp that holds the magnet on the flywheel.
Those facts made all my early measurements and calculations totally bogus.
In conclusion, I determined that the more I learn, the less I realize I know for sure.
A fish scale, a piece of flat stock and an eye bolt. You can now see what each magnet will hold. Dan
I just read James Golden's post that a 2 pound weight is not enough to start on mag...
Why then did ford say that was the test?
Anyway, I have mine easily picking up a piston, and I am shooting for a tight mag to coil ring gap of 0.025" and I have 0.003" end play, sooo... holding thumbs because I do not want to do that magnet zapping exercise again!
Might be handy to have????.....
You don't have to stop testing if the magnet can lift a 2 lb piston. Here's one that lifted 2954 grams (6.5 lb) of piston, wrenches and misc hardware. Recharged on my little home-made charging station.
All good info and very much appreciated.
Chris' can you give me specifics on your homemade rig? I'd like to build one myself but don't know where to start.
Thanks' Mike G.
Mike, I went from a description found on the Forum a few years ago. You might be able to find it with a keyword search.
The photo should be almost self-explanatory, but note that the red and black wires are wound in different directions (CW & CCW) and I understand this is critical to success. I used 10 or 12 ga house solid core copper house wire.
I set the charger to 100 Amp Boost and flash the clamps to the charger terminals about 15-20 times (a few seconds in-between to cool off). I believe the briefer the better on those flashes, as it reduces heat buildup in the wire and anyway it is the collapse of the current flow that does the work.
Caveat — my setup is contrary to the recommended design with many, many turns of wire, so there may be some long-term problems with recharging this way — still, the first set I did seems to work just fine three years later.
The red wire is wrapped around "which" side of the magnet if you were to look at them mounted on the flywheel?
That rig would be easy to manage.
Ken in Texas
Ken, I believe the red wire wraps around the previously North pole.
Justin, I did not say it was not enough I said it was the minimum acceptable possible level to operate the Mag and not near as much as could be had for an output.
This device was used to charge golf cars with six 6 volt batteries in series and puts out 40 volts DC at 40 amps. when applied to the flywheel, it will provide a nice charge.
I was hoping it was enough. Much appreciated,
Charging a set of magnets that are installed on the flywheel, using a mag coil ring, as shown in the MTFCA electrical system booklet works pretty good.
Here's a link to a site showing how to build your own inexpensive gaussmeter: