Tonti alternator conversion Q

[wirespokes]

I know the early Tontis with the Bosch alternator can be converted to the 90s style Ducati permanent magnet alternator.

I'm curious if the early bikes will accept the newer permanent magnet alternators. The early ones spin a magnet within the stator, the newest spin a 'cup' around the outside of the stator.

[Antietam Classic Cycle]

After looking at photos of the parts (on a V7 850 E5), I'm going to say that no, it will not fit without major modification. First off, the tapered "nose" of the cranks is completely different, so the rotor/"cup" will not simply bolt on. Secondly, where would the stator mount? Inside the Tonti alternator cover isn't going to work. Lastly, it runs in oil for a reason, I'm guessing to keep it cool. To do that, the alternator cover would need to be sealed to the timing cover.

The Ducati permanent magnet alternator from a late Tonti isn't a direct fit onto an early Tonti either. The crank of a late Tonti has a straight "nose" and the early Tonti has a short taper.

If you want increased charging output on an early Tonti, then the Euro MotoElectrics high output alternators are really the way to go. https://www.euromotoelectrics.com/product-p/edl3-105.htm , https://www.euromotoelectrics.com/product-p/edl4mg.htm

[wirespokes]

I didn't know that about the oil bath. Those are significant differences and I agree - the newest is a no-go.

As for the Ducati permanent magnet having the only difference being the straight (key way) mount versus taper fit, I knew that. I've heard of someone making an adapter before the kits became available.

Thanks for checking this out Charlie! I was more curious than anything if it could be done. The PO of my G5 installed the EME alternator (among other things) and I'm totally happy with it.

[Antietam Classic Cycle]

As for the Ducati permanent magnet having the only difference being the straight (key way) mount versus taper fit, I knew that. I've heard of someone making an adapter before the kits became available.

Joe Kenny used to make the parts (when his machine shop was in Floyd, VA) for EME to go from straight shaft to tapered, and different holders for the stator as well. I'm not sure who is making them now.

[guzzisteve]

As for the Ducati permanent magnet having the only difference being the straight (key way) mount versus taper fit, I knew that. I've heard of someone making an adapter before the kits became available.

I thought years ago I saw an adapter made in the EU but I would not know where to look now. Possibly HMB or G&G did it. Any machinist here?

Wow, beat me to it, could have been Joe Kenny or I'm remembering wrong

[Antietam Classic Cycle]

What Joe Kenny was making was a complete "core" for the rotor, not a simple adapter. The original "core" was pressed out and the new one pressed in. He also made new rings that secure the stator to the timing cover. I'm not sure what was different about those.

[wirespokes]

Here I thought it only took an adapter to mount the newer rotor to a tapered shaft. Now I find out the stator mounts are also different. What about swapping timing covers? Will they interchange?

[Antietam Classic Cycle]

Here I thought it only took an adapter to mount the newer rotor to a tapered shaft. Now I find out the stator mounts are also different. What about swapping timing covers? Will they interchange?

Just did some measuring and test fitting of the Bosch stator vs. the stock Guzzi Ducati stator. Both are 105 mm, bolt holes in the same locations. The stators will swap over without any modification!

It seems the only reasons EME has different stator mounting rings are they are a bit nicer made/nicer looking and they have their name engraved into them.





 

[Vagrant]

Oil bath is a poor choice of words. It's not flooded in there. It just gets the breather routed through it so "mist bath" is more appropriate.

[wirespokes]

Thanks for going to the trouble checking that out Charlie! I like this ducati alternator, and with the Shindengen rectifier/regulator it's a simple, rugged and dependable system. If I only need to adapt the rotor, it seems a worthwhile project.

[n3303j]

I don't have the parts in front of me but did swap out my dead T3 rotor this spring, then pulled my V11 Ducati rotor for a chain tensioner replacement last week. Looked at the straight shaft on the V11 and wondered if the internal shaft in the rotor from the T3 would fit the bore in the Ducati magnet allowing the Ducati magnet to bolt up to the T3?

If it wasn't an exact fit it wouldn't be too much of a lathe project to create an exact fit. I feel bad that I tossed the T3 rotor because now I have to wonder.

[Antietam Classic Cycle]

I don't have the parts in front of me but did swap out my dead T3 rotor this spring, then pulled my V11 Ducati rotor for a chain tensioner replacement last week. Looked at the straight shaft on the V11 and wondered if the internal shaft in the rotor from the T3 would fit the bore in the Ducati magnet allowing the Ducati magnet to bolt up to the T3?

If it wasn't an exact fit it wouldn't be too much of a lathe project to create an exact fit. I feel bad that I tossed the T3 rotor because now I have to wonder.

I guess one that is "handy" and has a lathe could use the "core" from the Bosch rotor to replace the one in the Ducati rotor, if it would be long enough. However, if one is that skilled, they should be able to make a completely new core.

I'll contact Joe Kenny to see if he might still have his CNC files and program.

[wirespokes]

I was thinking the same thing - and I've got a couple dead bosch rotors.