Samir13k Posted September 14 Report Posted September 14 Hello All, I’m at the tail end of my nightmare annual (I hope) where I’ve essentially brought a plane back from the scrapyard at this point. Engine is due back from overhaul in mid to late October and trying to get the final pieces in place. 1968 M20G (680021 Serial) The MX is letting me source parts to try to save a little bit of money, but I’m struggling to find alternator brackets. The fall-back plan is to buy the plane power, but an overhauled ALY-8520 is about $800 so I’d rather take that route if I can. The alternator that was on the plane was a CarQuest Alternator which the MX won’t put back on the plane (pictured). All of the manuals I’ve looked at show the generator, not the alternator. It should be the same as the M20C (Lycoming O-360-A1D). The alternator overhaul shop I was buying an alternator from said they have a bin full of brackets but they would need dimensions and a photo to see if they can find the correct brackets in the bin. Does anyone know where the correct brackets can be found, or can anyone share their bracket images and dimensions? (Or have an alternator and brackets they want to sell? Can be a core. (also on the hunt for an overhauled oil cooler…) As always, thank you in advance! 1
takair Posted September 14 Report Posted September 14 Try @Jerry Pressley Or Allan Fox As a side note….i feel your pain. I am finishing up restoration of an experimental airplane. I decided to add an electrical system to include an alternator. I decided to do automotive with my own design Overvoltage protection and brackets. I never did find off the shelf brackets that worked and ended up having to do lots of mods. In the end, I was wishing I bought Plane Power or B&C. I give them credit for those aircraft specific components that make the difference between easy and hard. As a side note, I put a PlanePower on my Mooney years ago and have had no issues. Install was relatively easy, after you trim the baffles. 1
Ragsf15e Posted September 14 Report Posted September 14 3 hours ago, Samir13k said: Hello All, I’m at the tail end of my nightmare annual (I hope) where I’ve essentially brought a plane back from the scrapyard at this point. Engine is due back from overhaul in mid to late October and trying to get the final pieces in place. 1968 M20G (680021 Serial) The MX is letting me source parts to try to save a little bit of money, but I’m struggling to find alternator brackets. The fall-back plan is to buy the plane power, but an overhauled ALY-8520 is about $800 so I’d rather take that route if I can. The alternator that was on the plane was a CarQuest Alternator which the MX won’t put back on the plane (pictured). All of the manuals I’ve looked at show the generator, not the alternator. It should be the same as the M20C (Lycoming O-360-A1D). The alternator overhaul shop I was buying an alternator from said they have a bin full of brackets but they would need dimensions and a photo to see if they can find the correct brackets in the bin. Does anyone know where the correct brackets can be found, or can anyone share their bracket images and dimensions? (Or have an alternator and brackets they want to sell? Can be a core. (also on the hunt for an overhauled oil cooler…) As always, thank you in advance! I may actually have an aly-8520 in my hangar collecting dust. It was working as well, but could probably stand new guts. We took it off my ‘68F and installed a new plane power alternator only to find that the alternator wasn’t the problem. Eventually I found a slightly corroded connection that was causing my issue, so long story short, I have an alternator. Ill get a picture of it this afternoon. The bracket might be tricky. Have you tried BAS? I’ll look, but i thought my mechanic reused my bracket for the pp alt. 1
47U Posted September 14 Report Posted September 14 4 hours ago, Samir13k said: overhauled ALY-8520 Is the installation of the ALY-8520 accomplished with an STC? I’d think that paperwork would include the part numbers for the brackets? If I remember, @Ragsf15ehad an F model (and he’s since upgraded to the Encore) but if you can track down the STC paperwork that might help your search for the right bracket. 1
N201MKTurbo Posted September 15 Report Posted September 15 Does your engine have the mounting boss for the alternator? If not, there is a bracket that bolts to three of the case parting bolts.
M20GforMe Posted September 15 Report Posted September 15 8 hours ago, N201MKTurbo said: Does your engine have the mounting boss for the alternator? If not, there is a bracket that bolts to three of the case parting bolts. I'll have to ask the engine rebuild shop, it's out of state so I can't get a look at it easily unfortunately. I may suck it up and just order the plane power. It looks like it may be worth the money to not chase this part from others experiences 20 hours ago, 47U said: Is the installation of the ALY-8520 accomplished with an STC? I’d think that paperwork would include the part numbers for the brackets? If I remember, @Ragsf15ehad an F model (and he’s since upgraded to the Encore) but if you can track down the STC paperwork that might help your search for the right bracket. I know the STC was with the logs as there was a separate folder of documents just for the conversion. I'll see if the shop can look it up, thanks for the guidance!
Ragsf15e Posted September 15 Report Posted September 15 On 9/14/2025 at 5:14 AM, Samir13k said: Hello All, I’m at the tail end of my nightmare annual (I hope) where I’ve essentially brought a plane back from the scrapyard at this point. Engine is due back from overhaul in mid to late October and trying to get the final pieces in place. 1968 M20G (680021 Serial) The MX is letting me source parts to try to save a little bit of money, but I’m struggling to find alternator brackets. The fall-back plan is to buy the plane power, but an overhauled ALY-8520 is about $800 so I’d rather take that route if I can. The alternator that was on the plane was a CarQuest Alternator which the MX won’t put back on the plane (pictured). All of the manuals I’ve looked at show the generator, not the alternator. It should be the same as the M20C (Lycoming O-360-A1D). The alternator overhaul shop I was buying an alternator from said they have a bin full of brackets but they would need dimensions and a photo to see if they can find the correct brackets in the bin. Does anyone know where the correct brackets can be found, or can anyone share their bracket images and dimensions? (Or have an alternator and brackets they want to sell? Can be a core. (also on the hunt for an overhauled oil cooler…) As always, thank you in advance! I’m not sure if this would help you or not, but let me know. It is a Prestlite ALY 8420. It was working fine when we removed it. I do not have the bracket for it though.
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