No announcement yet.

Building my first Harley one part at a time


Desktop Ad Forum Top


Mobile ad top forum

  • Time
  • Show
Clear All
new posts

  • #31
    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.

    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.
    Last edited by farmall; 01-02-2022, 6:42 PM.


    • #32
      I don't know if guys would want this system being that your choices are Mitsubishi or chineseium boxes. And the idea would not to be modifying the rotor at all. If I really have trouble finding a stator that fits I'll take a burnt stock one remove 3 post dovetail in the AC stator and do a custom 3 phase winding. I have done it before and it works. Doing the math on the new windings and pattern are the hard part.


      • #33
        If I did the mod it would run a 9 post Y or delta termination.(for charging battery and lights) I could probably just use the same math as when I rewind brushless motors for drones. There's so much empty space on those post I think I can do that with minimal loss to efficiency.

        Edit: after a look I should have took before posting. This will work, but would not use any harley electric parts at all the rectifier regulator would also be Mitsubishi or chineseium. And I'm thinking 12-20 T delta termination.
        Last edited by CaNaDiAnNuTcAsE; 01-02-2022, 7:01 PM.


        • #34
          Mitsi rectifier regulators are good stuff. No reason not to use one on an HD which come with tons of offshore parts like the killer Denso starters.

          If there's a good quality Japanese CDI that might drop in even better. Thoroughly cool idea regardless.

          Do you rewind professionally? If there's a local industrial rewinder/rebuilder that might be a worthwhile gig and their stuff of course is much less delicate.
          Last edited by farmall; 01-02-2022, 10:02 PM.


          • #35
            I rewind as a hobby I've done 12 pole stators down to 14mm diameter and run 20A at 16.8 volts though em DLRK delta termination. Not only that when I do one I have to do 3 more the same.(race drone motors)

            When I was younger the cheapest motorcycles with the least problems were the ones with dead electrical. I spent years learning how to fix em. Five years ago something clicked and there is not a small engine in existence I can not build a system for under $200. In some cases it takes some fabrication, but I have not been defeated since.

            Because of this I have saved lots of engines people would otherwise scrap. It's all with honda 4,5,6 wire cdis (Mitsubishi works as well) the Chinese copy the hell out of them and with a few tricks they can be modified to run about anything. With resistors you can even use points. Yes many have built in timming curves, but a little testing you can find the right setup and do some cool shit.

            If you ever need a cdi for a 93 yz 250 the blue aluminum AC box gives you the most wonderfully violent power delivery a YZ can get. With stock stator and pickup. I put a lot of time on that setup and had full trust in it. Hell I ran from cops a half dozen times before they caught me on my other bike and flat out stole it from me.
            Last edited by CaNaDiAnNuTcAsE; 01-02-2022, 9:22 PM.


            • #36
              Would I be correct in the timing rotor being 225 or 135 degrees. (180 + or - 45*) I'm going to do a bunch of parts up in the 3d printer so once i have my cam and electronics i can build them from metal.

              Edit screwed that up. 202.5? Forgot to cut the 45 in half
              Last edited by CaNaDiAnNuTcAsE; 01-03-2022, 3:08 PM.


              • #37
                I've the complete Cycle Electric kit to measure so post any dimension you wanna know.

                The caliper is used as a pointer since I'm not an octopus so the actual measurement is 134mm nominal OD. (Coating and build tolerances wouldn't vary much.)

                I don't recall the timing degree info off the top of my head but JB and Drag can chime in with advanced knowledge of stock and "stuff they'd like to see".

                I mostly just fix 'em when they break as I'm no racer. The Harley Tech Talk forum would be another place to ask advanced ignition tech questions but its kind of slow.
                Attached Files


                • #38
                  Thanks that's great. I'm having a real hard time getting a price on used heads. People keep saying they have em and not giving me a price other than one guy who offered an entire top end more than twice what I can pick up a complete engine for. I may go the ebay route and get a little raped on the shipping. Trying to avoid it I like buying direct from people as its good to get to know people with parts. I have always found once you buy a few things off a guy in person the prices tend to drop. Not only that I've made a few really good friends that way.


                  • #39
                    Originally posted by CaNaDiAnNuTcAsE
                    Would I be correct in the timing rotor being 225 or 135 degrees. (180 + or - 45*) I'm going to do a bunch of parts up in the 3d printer so once i have my cam and electronics i can build them from metal.

                    Edit screwed that up. 202.5? Forgot to cut the 45 in half
                    Rear cylinder fires 315 crankshaft degrees after the front cylinder, so a cam mounted trigger would be half of that, or 157.5 degrees.



                    • #40
                      Study which year heads are prone to cracking. (Later is better.)

                      Dismantlers on Ebay like Deadparts and Pinwall have incentive for customer service and no incentive to sell trash because feedback matters. I've bought from both.

                      Cheap complete engines tend to be the best parts deals if bought locally and you can open them to inspect or they're already partially torn down. I like donor wrecks too (for bikes, trucks, anything) since they were running when they crashed.

                      A leftover or scrap left side engine case could make a convenient alternator test jig and a junk crankshaft could provide the output shaft. If ya mix cases they need line lapping (since you can make your own laps that's not a huge deal for someone with your assets).

                      If you can take overflow work from other machine shops that could quickly generate more cash to choose from a better class of parts.
                      Last edited by farmall; 01-03-2022, 6:15 PM.


                      • #41
                        Originally posted by farmall

                        If you can take overflow work from other machine shops that could quickly generate more cash to choose from a better class of parts.
                        I don't have my lathe/mill with me at the moment it's back home. It's just a little guy with a 4 jaw since true center was more important to me than time. Also no power feed 100% manual. I can build good stuff on it, but it takes me a lot longer than a professional.

                        Before I had it I modified the hell out of a few old drill presses ( threaded the spindle and chucks on a lathe a guy let me use) put a xy table on them and ran em till the run out made them useless.

                        Then I used my food and rent money for the lathe mill combo and starved for a couple months. It was worth it.


                        • #42
                          If anyone has a burnt out stator I'll happily take it for science purposes. Usable ones are cheap, but bringing myself to ruin working parts is a hard thing to do.


                          • #43
                            I've none at the moment but putting out word to your local bike shops should net a few pretty quickly.

                            The HD design is idiotic with its buried poorly-cooled stator (besides the maintenance-intensive primary arrangement with left-side sprocket) so it has a high mortality rate.

                            If you've use for old alloy regulator cases those will be shitcanned in similar numbers.


                            • #44
                              What's idiotic about them is the ridiculous high turn count and single phase coupled with stupid high amp draw.(Some of these things claim 45A) The longer a phase the higher the internal resistance and the more fucking heat. From what I've seen its 30-35t 18g wire.

                              Me going three phase at no more than 20 on 16g and 3 post less each phase (Delta) will be way under 1/4 of the resistance. So way less heat build up. There are draw backs but almost every Japanese bike (street legal) is running 3 phase for a reason.

                              I think the reason for going single is the cheap as dirt H bridge rectifier's (4 diodes in one IC) They are real cheap and I'm sure you guys blow lots of them. I'm not saying I'm some electrical wizard, but I feel like this area is not a strong point for these bikes. Also some of the windings on these bikes looks like some guy hand wound them. (No fucks given to stacking the post) Although if done right it's no problem, but nice clean looking post keeps the wires from rubbing each other. (The most common cause of failure) As soon as the enamel rubs off and the wires touch you have just got yourself a short. That will heat the fuck out of that one post until it smokes. This is why some stators are epoxy dipped (I do hate this when unwinding).

                              If you ever look at a burnt stator. A bunch of burned post= high draw. One or a couple burnt= short caused by rubbing wires

                              This is the last rewind i have done 9 post 10t delta that little fucker spins 3600 rpm per volt at 17v unloaded and loaded pulls 20A. Its stator is 14mm across and 8mm tall.
                              Click image for larger version

Name:	rewind.jpg
Views:	1
Size:	33.9 KB
ID:	1321539
                              Last edited by CaNaDiAnNuTcAsE; 01-04-2022, 2:02 AM.


                              • #45
                                Well i got my case back from the welder. Just as I had known another crack appeared. This one is not all the way through. It's sad, but this engine will need new cases eventually. I'm to broke to buy em now and I've chased case cracks before, if I keep welding all I'm going to get for my efforts is a warped case if it is not already.

                                So I carefully hand filed the weld down where the cases meet and will continue to build the engine. Once I get it built I will use the engine to get me going and test out my electrical. Once I get my bike up and running I will find a new case set and do a proper engine build with new cases.

                                I will never sell this to anyone. And I fully accept that the engine will not last much longer, but I will not give up on building the bike I have been dreaming of since I was a kid. I also knew going into all this that I would be replacing parts after the bike was built probably for the rest of its life. They say buy once cry once, but I do not have the money for that.

                                Also it looks like the case is cracked all the way in the pics,(The mark is gouging from the old mounts) but close inspection tells me that not the case yet. I have considered marking it and welding it once the cases are torqued down together in the hope they will not warp. That's a shit plan for shit results, but I did it on a shit engine before and it lasted the rest of that engines life.

                                Click image for larger version

Name:	20220104_162059.jpg
Views:	1
Size:	288.3 KB
ID:	1321547
                                Click image for larger version

Name:	20220104_162113.jpg
Views:	1
Size:	291.4 KB
ID:	1321548
                                Click image for larger version

Name:	20220104_163920.jpg
Views:	1
Size:	293.0 KB
ID:	1321549

                                Edit: Got in there with a hand file to really look for the crack on the outside and found nothing.
                                Click image for larger version

Name:	cr.jpg
Views:	1
Size:	296.8 KB
ID:	1321550
                                Last edited by CaNaDiAnNuTcAsE; 01-04-2022, 6:34 PM.


                                300 mobile ad bottom forum