The CDI idea ounds good. Make, model, source?
The HD alternator rotor is not a flywheel but the design is simple enough for easy mods if you wish (like turning whatever size "cup" you desire, cutting out and removing stock splines then welding the splined center into your cup if you don't feel like making a broach out of an output shaft or using a mill with indexer to machine a broach).
Some aftermarket HD alternator rotors encapsulate their magnets while others use structural adhesive similar to stock. The latter style would be easy to rework if desired by (for example) torch heating the adhesive from the rotor side (to be kinder to the magnets if you reuse them).
An improved more reliable version that could run batteryless could make you a nice profit. While the major reason chopper builders run external mags is their kool appearance there are enough HD owners who hate having to replace failed batteries that a quality conversion could sell strongly. Racers would be delighted with the weight and complexity reduction vs. a magneto since speed ain't about pretty.
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That crack is common but the cavity on the other side has room for weld bead intrusion so a thick repair might do the trick. There's enough room for a backing strip which is rare in casting repair but common in structural steel welding. One might provide support for a thick weld buildup then you could plunge cut using an end mill to remove it. Maybe mill out the crack, place a thick backing strip, tack, fill (taking care not to overheat since HD castings love to hot short then crack on cooling) and gradually let cool. Many small beads would be safer than a fat one. (I am very fucking far from a TIG ninja but I've followed a couple around. )
I've not looked into tiny TIG torches to see if one might reach usefully inside but oxy-acetylene repaired some spectacular damage in the early car days when crankcases were unobtanium. I failed to get his info but one gent I met at AMCA Denton preferred OA for case work and used scrap shavings from other cases as filler. You have two junk heads as fin/filler donors...
The mount surface would be easy to true to the other case on a mill. The area that interfaces with the other case isn't large.
Distortion could be controlled by bolting to a plate but a plate or the opposing case but I'd ask people who do MANY case repairs then copy success.
Dragstews does some very nice welding and could sort ya out with advice.
Also check the round lip the inner primary cover registers on as those frequently crack. The repair gaskets work nicely for me.
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Tatro likes Ultima crankcases but there are a variety. (I've not used them so I recuse myself.) You already own a set of flywheels and as you just found out stock cases are disposable. A fresh case set with MSO would have unimpeachable documentation.
The HD alternator rotor is not a flywheel but the design is simple enough for easy mods if you wish (like turning whatever size "cup" you desire, cutting out and removing stock splines then welding the splined center into your cup if you don't feel like making a broach out of an output shaft or using a mill with indexer to machine a broach).
Some aftermarket HD alternator rotors encapsulate their magnets while others use structural adhesive similar to stock. The latter style would be easy to rework if desired by (for example) torch heating the adhesive from the rotor side (to be kinder to the magnets if you reuse them).
An improved more reliable version that could run batteryless could make you a nice profit. While the major reason chopper builders run external mags is their kool appearance there are enough HD owners who hate having to replace failed batteries that a quality conversion could sell strongly. Racers would be delighted with the weight and complexity reduction vs. a magneto since speed ain't about pretty.
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That crack is common but the cavity on the other side has room for weld bead intrusion so a thick repair might do the trick. There's enough room for a backing strip which is rare in casting repair but common in structural steel welding. One might provide support for a thick weld buildup then you could plunge cut using an end mill to remove it. Maybe mill out the crack, place a thick backing strip, tack, fill (taking care not to overheat since HD castings love to hot short then crack on cooling) and gradually let cool. Many small beads would be safer than a fat one. (I am very fucking far from a TIG ninja but I've followed a couple around. )
I've not looked into tiny TIG torches to see if one might reach usefully inside but oxy-acetylene repaired some spectacular damage in the early car days when crankcases were unobtanium. I failed to get his info but one gent I met at AMCA Denton preferred OA for case work and used scrap shavings from other cases as filler. You have two junk heads as fin/filler donors...
The mount surface would be easy to true to the other case on a mill. The area that interfaces with the other case isn't large.
Distortion could be controlled by bolting to a plate but a plate or the opposing case but I'd ask people who do MANY case repairs then copy success.
Dragstews does some very nice welding and could sort ya out with advice.
Also check the round lip the inner primary cover registers on as those frequently crack. The repair gaskets work nicely for me.
----
Tatro likes Ultima crankcases but there are a variety. (I've not used them so I recuse myself.) You already own a set of flywheels and as you just found out stock cases are disposable. A fresh case set with MSO would have unimpeachable documentation.
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