I'm looking to add a right hand gear drive Bosch magneto to one of my T's and hoping to get some guidance and wisdom. what should i look into & ask when purchasing one of these units? And I assume they'll replace the generator and charge the battery as well? Thanks!
What model Bosch mag? But generally speaking, high tension magnetos aren't very good for charging batteries. I wouldn't say it could not be done. However I would expect that voltage regulation would be very difficult at best. Also, I don't think common high tension magnetos put out enough current to adequately charge an automobile battery.
I am also curious as to what mag drive you are planning to use. But that is just my model T curiosity.
My '16 DB has magneto ignition (Factory) and a separate Generator/starter.
My 1928 Indian 101 Scout has a Bosch DVAR magneto with generator, though it's only 30w and the magneto is for a twin engine. Haven't seen four cylinder magnetos with built in generators, but it might be possible? With some kind of regulator, maybe the standard Ford flywheel magneto could be used as a generator, while a Bosch high tension magneto makes the sparks?
Get a Cross drive. That way you can kept the Gen. Dan
Thanks for the replies gents. Sorry for the late reply myself... i have not been receiving notifications of your responses.
As far as Bosch model, i'm really open to any ideas/suggestions. The more i have narrowed down what may be most versatile for me, i'm beginning to look close at a distributor to maintain the generator. I'd be interested in a cross drive but the chain feature concerns me for the potential stretching and throwing the timing off. Maybe not a major concern?
A cross drive doesn't use a chain. The one Dan is talkin about uses a special timing cover plate. The magneto sits sort of angled up an over the radiator inlet pipe.
Probably a dumb question, but...
Model Ts came with a magneto, why did folks add these back in the day?
I bought a 1920 Fordson tractor that had been converted to one. Considering that the Fordson tractor had NO provisions for running on battery and as a 450 cu in 4 cylinder engine and no provision for a electric starter it was not easy to crank it fast enough for the T style mag to start it when the magnets got old and the coils needed tuning.
The Splitdorf/Dixie mag had a impulse coupling so delivered a really hot spark irrespective of engine cranking speed and was very reliable.
So I have not directly answered your question, but perhaps related
When I rebuilt the tractor I converted it back to stock
Mark, to answer your question, here are some reasons why one might prefer a high tension magneto:
A high tension magneto provides all the same benefits of the Ford magneto, in that you don't need a battery to run the car. Plus, with an impulse coupling they deliver hot spark even when hand cranking.
The spark distribution system is superior because it has a single set of points (as opposed to 4 sets with the standard coils). It's much easier for it to deliver an accurate and consistent spark at high RPMs. Also, the actual "distributor" potion of the high tension mag does not require the front timing cover to be perfectly centered.
They're also easier to work on if something ever goes wrong. 4 quick bolts and you can remove it.
There were a lot of different external magneto drives for model Ts. The most common types were multiple gear type for pre-generator blocks that ran external to the T's timing gears and placed where the generator was later placed. Both Bosch and Eisemann are common, however, there were a few others as well. After Ford allowed for a generator on their block (1919), several companies including Bosch and Eisemann made a cheaper and simpler mount to hold an external mag in place of the generator. These were often used on cars or trucks that did not have a generator for whatever reason. Race cars often used these type also. This type ran a special gear off of the standard model T timing gear.
Chain driven external magnetos were less common ready made in the after-market business. Home-made ones were simple, and fairly common, but few seem to survive.
The cross-drives like Seth posted pictures of are popular with the speedster people today. They were manufactured by quite a few companies, and for many years. One of the reason so many of them survive today, is that they were often used on model T engines sold by Ford to run non-Ford equipment. Some of these engines were sold as "short" engines, as they did not need the transmission and full pan to run a farm combine, pumps, saws, or some kinds of boat or tow motors. These engines were then mounted on special short pans, with some form of oil circulation, and their own flywheel and clutch (which often did not have the magneto as supplied in the full Ford engine). For that reason, many of these engines had external magneto drives to power the ignition. Many of the surviving cross-drives apparently came from such engines.
Few of the model T versions of these engines survive because most of them were well used up by the late '30s. The model T versions were a bit under-powered for many of the uses they were put to. The model A versions had more power, were newer, and many survived the war years to be parted out for model A restoration during the '50s and '60s.
The short pans can sometimes be found as well as the magneto drives. Popular cross-drives include again Bosch and Eisemann, along with Matco and Columbo. I think the second one pictured by Seth is a Columbo. The first one is likely either a Bosh or Matco. I can't quite read it in the photo.
SOMETIMES the drive gear has been lost (left with the engine when the drive was removed), and can be difficult to get. One of the more common of the cross-drives has had the drive gear reproduced. It has been available from the model T parts suppliers for quite some time (it is a bit pricey). However I am not sure for which ones it works, so check with your favorite supplier for make/model compatibility and availability.
The reason for so many external magneto drives is an interesting subject to speculate upon. I won't claim to know the definitive answer. Certainly, the "short" engines explain a lot of them. And racing uses accounts for many more (lighter weight, no battery, cut down flywheels, etc). But there were a lot of external magnetos used on basic everyday model Ts. One would expect, that back in their day, enough people that understood them, and garages with HCCTs, were around that maintaining the Ford ignition system was not a big problem. Most of the folklore of the "unreliable" model T ignition system was from the late '30s, war years, '50s and '60s when the system was old, forgotten, and model T garages were mostly gone. Most of these external magneto drives were manufactured long before the system became really unreliable (especially the multiple gear types that fit only pre-'19 blocks).
High tension magnetos were used on many expensive cars and trucks well into the 1920s. Tractors used them even much later. Some people would of course buy such an after-market ignition system like the "BIG" cars had. But still, there are a lot of those magnetos and drives around today.
Fun to think about.
Drive carefully, and enjoy, W2
I think some were added to to weak or dead flywheel magneto. But I agree most were on stationary units
Now side question early bosch drive did the mag rotate clockwise or counter clockwise
On the Bosch "Triple Gear" front plate (the one for non-generator motors) the mag rotates counter-clockwise.
Triple gear turns left
Chain drive turns left
Very rare front plate turns right, note the magneto/generator similar to Roger's Indian.
I believe the shaft drive model also turns left.
It used the same mounting bracket as the chain drive but replaced the chain with 2 sets of gears and a shaft between them.
Bob, How is that for too much info!
I'd like to find me a set up like Seth has a photo of above. That'd be ideal to keep the headlamps operational to drive the speedster about during the evening/night time!
Thanks enouf for me to be dangerous
Once I get car home and find a good HOT mag installation shall Comanche
I'm installing one I bought from Bob Middleton. It needed a rewind and a capacitor, now the impulse drive snaps a good spark. You wouldn't use this to charge a battery as there is nowhere to pull low voltage off of it.
TH looken good
I bought the mag sight unseen and Terry had dump alot into its rebiuld ( sorry about that).
So i would suggest buying a mag from a good source and check its spark.
Theres a couple good magneto rebiulders so i suggest talk to them first and if you buy an old mag make sure its complete and cheap
About mag drive check with Dan Maceachen (sp) sorry Dan as he makes mew gears for most drives
It be super if we had a sourch for chain drive setup
Hi J. Ryan,I have this Bosch combination 4-cyl mag on the bottom and generator on top,original application unknown. It's a type G4N4,ED 2V1,whatever that is,and 12 volts. Have to figure out a drive and 12v starter but that should spin that T motor over pretty well,maybe through a resister would be best. It's for sale if you have any interest.
Re; i have not been receiving notifications of your responses.
You have to open and read the postings there is no way to set this system to send you an email to let you know that there have been postings on your question.
New Drive gear sets are available for Columbo, Matco/Eiseman Cross drives and the single gear Bosch side drive that replaces the generator.