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Auto Alternators

rapid_ascent

Well Known Member
There are lots of old threads on using auto alternators. I've read through lots of those and it's still not clear what a good direction is. I'd like a 50+ amp, external regulator alternator. Preferably counter clockwise rotation. Also, I'd prefer not to have to swap the pulley to a single groove pulley. Anyone gone down this path recently?

Another thing I'm unclear about is the mounting bracket and whether the alternators require different brackets. There seem to be some previous discussion on this. Where is the best place to find the brackets?

There is always the B and C route but I'd like to understand the auto options better before making my final decision.
 
My recommendation based on experience

I'd go with this auto alternator.
V-belt pulley is correct.
It's internally regulated but I'm ok with that.
You could be too ;)

https://www.oreillyauto.com/shop/b/charging---starting-16772/alternator-11425/f7cab2ae3cc0/1987/suzuki/samurai

Buy it once and have a lifetime warranty.
Pretty sure I got the brackets from VANS.

I'm on my third one and have 1625 hours on the airplane.
Failures were intermittent low voltage at idle, i.e. not scary!

I'd go this way again.

Mark
 
I have used these alternators to replace Plane Power alternators. They have been 100% reliable.

The spec sheet that comes with these show output above 60A.

As far as brackets go I have fabricated them and I have also modified the Plane Power bracket with a simple bushing turned on my lathe. I've also used the boss mount alternator brackets Van's used to sell but I can no longer find them on their site.

Worth mentioning I've never used a blast tube.
 
Possible alt list

I have done quite a bit of hunting to find the same thing -
  • >= 50 amp
  • Spins the correct way
  • external regulation
Probably searched through every RV alternator thread out there. Here is my list of possibilities that mostly fit those three criteria:

ND 14198 ('79 Civic) - no 2 hole mount
ND 14591 ('83 Honda)
ND 14158 ('81 Accord) 50 amp
ND 14593 ('82 Accord) 60 amp Serpentine belt
Bosch AL257X
ND 021000-982
ACDELCO 334-1555 or -1551

I'm 1-2 years from installing the alt but this is something I'm really interested in. I figure even if these are only built to 80% of the quality of the B&C items, thats ok because they are dirt cheap and you can pick them up quick just about anywhere.

If anybody knows more about the physical installation aspects of these I'd sure like to hear.
 
I have some of those same alternators on my list.

1976 Honda Accord 1.6L

Bosch AL257X (NAPA, Summit Racing)
14591 (Autozone)
14158 (Advanced Auto, O'Riellys)

Van's doesn't appear to sell the mounting bracket any more. It looks like B and C is the best option for a premade bracket. I'm not sure it will fit though.
 
Personally I would shy away from any of the older alternator designs, for a couple of reasons:

1. Local availability (don't see many 82 honda civics on the road)
2. Design improvements
3. Size (smaller)
4. Reliability improvements

The 12179 knockoffs are cheap enough you can have more than one spare shelf. I have a few but have yet to replace one thats been in-service.

Fan direction seems to have no effect on reliability in my experience.
 
I found the Vans brackets for those who are interested. Doing a search for Alternator didn't work since it's not in the title I guess. I tried ALT and that provided two different possible brackets.
 
Had a Prestolite but.....

would not fit in the cowling (for sale if anyone wants it)

After hours of reading and consulting my opinion is that if you are knowledgeable the Automotive alternators may be an option.

However, in that poll which i read long ago it was discovered that many B and C alt. go 1000+ hrs.

I went with a B and C alternator and it came with a bracket. Some things are better left alone and having an alternator failure VFR at night with a glass panel was not on my list of fun things to do.

IMHO - go B&C.
 
Why counterclockwise rotation?

snipped I'd like a 50+ amp, external regulator alternator. Preferably counter clockwise rotation. Also, I'd prefer not to have to swap the pulley to a single groove pulley. Anyone gone down this path recently?

Why do you want a counterclockwise rotation alternator? Lycoming spin clockwise. Honda's older models also spin clockwise. Just about every other car manufacturer has their engines turn counter-clockwise. External voltage regulation on automotive alternators pretty much went away after the 1983 model year.

Auto manufacturers All pretty much did away with external voltage Regulators after the 1983 model year. However Chrysler in the mid-90s in their wacko wisdom decided to make the voltage regulator part of the engine computer rather than being an internal component of the alternator. go to the auto parts store and ask for an alternator for a 1995 Dodge half ton van. Engine size doesn't really matter. you'll get a nice Nippon Denso 70 - 80 amp alternator that spins counter-clockwise. Best of all it's set up for external voltage regulator because Chrysler put the voltage regulator in the engine computer. If you have a half inch air impact gun it's very easy to take the nut off and change the pulley out. Can be done in under 3 minutes.

Charlie
 
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Direction of rotation may depend on how it's defined on engine vs alternator. If you define alternator rotation looking from the pulley end, it would be counter-clockwise. Anyone know which case holds?

I too am alternator shopping but would like an 80A unit (electrically dependent engine, IFR, some goodies, and I want plenty of margin). I found a potential Denso unit on Summit but I need to verify a few things. If anyone has already picked out such a beast with external regulation I'm all ears.
 
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Does rotation really matter? It's AC output. The rectifier doesn't care which way the rotor spins.

A 1g Ford alternator that's been upgraded to 55A+ internals would fit the bill. I've taken them apart and I don't recall seeing anything internally that was directional but I wasn't looking. The only thing that would be is the cooling fan. I have one sitting on the shelf I could disassemble.

I have this Powermaster on my '68 Mustang and it works. I don't have much time on it though. There are millions of Ford 1g alternators out there. They come in all sorts of cases as well.

The Aerotech and Falcon alternators are a spitting image of Ford 1g units..
 
HEAT IS THE KILLER....
Shield the Alternator for exhaust pipe heat as much as possible
Air blast tube on regulator (back) is a good idea.
Balance your prop... fixed or CS... less vibe's the better.
+1 on advice you got in this thread.
 
I have the Denso 021080-0760 with an external crowbar to shut off the field voltage. A spare in the hangar cost $90.

120 hours so far and all nominal (to use NASA-speak).
 
Direction of rotation may depend on how it's defined on engine vs alternator. If you define alternator rotation looking from the pulley end, it would be counter-clockwise. Anyone know which case holds?

I too am alternator shopping but would like an 80A unit (electrically dependent engine, IFR, some goodies, and I want plenty of margin). I found a potential Denso unit on Summit but I need to verify a few things. If anyone has already picked out such a beast with external regulation I'm all ears.

Going to be tough to find an 80A alternator with external VR. However, an IR alternator can be easily modifed to take a field from an external VR. A bit of surgery and soldering, but pretty easy and straight forward.

Larry
 
Why do you want a counterclockwise rotation alternator? Lycoming spin clockwise. Honda's older models also spin clockwise.

SAE J 824 set the standard for how we describe auto engine rotation. It dictates that in cars, you describe rotation from the point of view of looking at the rear flywheel. So the most common rotation in cars is CCW.

Engine-Turns_11.jpg


We know that our Lycommings spin the opposite direction - hence you want an alt for a CW engine if you are one of the folks that thinks the fan direction matters.

I usually find the most detailed specs for alts on rockauto.com . When you look up the Dodge alternator you mentioned (ACDELCO 3351182), it lists the "Rotation Direction" as clockwise. But when you look up a 1982 Accord, (ACDELCO 3341650), it says counterclockwise. Just about any other vehicle you lookup describes alt rotation as clockwise.

So that proves to me that despite car engines turning CCW, the alternators rotation is described the opposite way, as if you are looking at the front of the pulley.

That dodge one is definitely added to my list though. Available new, its more modern, LOTS of amps, external regulator, and many folks say fan direction doesn't matter.
 
Going to be tough to find an 80A alternator with external VR. However, an IR alternator can be easily modifed to take a field from an external VR. A bit of surgery and soldering, but pretty easy and straight forward.

Larry

Powermaster makes 1g Ford alternators that are externally regulated in 55, 90, and 125A (min) rated. There is still the issue of fan rotation.
 
Alt

We have a amazon ?one wire? alternator
60 amp? 1200 hours and just for piece of
Mind changed the belt last week.
 
I have the Denso 021080-0760 with an external crowbar to shut off the field voltage. A spare in the hangar cost $90.

120 hours so far and all nominal (to use NASA-speak).


How do you cut field voltage? Field is internal. The only thing you have access to is +B (output). The connector on back is typically the "ignition" (wake/sleep) and low volt light. Just asking. Thanks
 
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How do you cut field voltage? Field is internal. The only thing you have access to is +B (output). The connector on back is typically the "ignition" (wake/sleep) and low volt light. Just asking. Thanks

Depends on the alternator and we've had this discussion before. Many IR Denso alternators have 2 or 3 terminals. Take 12V off one external control terminal (usually marked IG) and charging stops:

https://www.youtube.com/watch?v=NvQRHuNpjss
 
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Going to be tough to find an 80A alternator with external VR. However, an IR alternator can be easily modifed to take a field from an external VR. A bit of surgery and soldering, but pretty easy and straight forward.

Any information/guides?
 
Going to be tough to find an 80A alternator with external VR. However, an IR alternator can be easily modifed to take a field from an external VR. A bit of surgery and soldering, but pretty easy and straight forward.

Any information/guides?

Well, I've found some of my own answers, at least. And finally figured out how alternators work, in an applied/practical sense.


http://www.aeroelectric.com/articles/Alternators/One-Wire_Alternator_Conversion.pdf seems to be a pretty good process for conversion and I can get my head around the mods on the case/housing, but the details about modding inside the voltage regulator aren't clear (the pic is pretty low-res). I suspect it would make more sense once I got my grubby hands on one to play with. Perhaps even a more direct means of applying field current would become apparent if one were willing to just skip the included 3/4 prong plug, but I can't tell just from a couple of pictures.

If I decide to go down this path I'll try to document it with better (and more) pictures.


Regarding an alternator itself, the Denso 210-0208 off the 1995-1996 Accord looks like it work well. 80A and counterclockwise rotation (from pulley end). I'd have to find a pulley to work with it though, and do the surgery.

Best part is Summit carries it for about $100...
(edit: $130 with the core charge...)
 
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I have used these alternators to replace Plane Power alternators. They have been 100% reliable.

The spec sheet that comes with these show output above 60A.

As far as brackets go I have fabricated them and I have also modified the Plane Power bracket with a simple bushing turned on my lathe. I've also used the boss mount alternator brackets Van's used to sell but I can no longer find them on their site.

Worth mentioning I've never used a blast tube.

Regarding using one of these to replace a PP alternator... I have a lathe and can likely figure out mechanical mounting details, but curious about what else is required for the swap. PP alternators have overvoltage protection built in, or so they say. Did you address that or that built in to these? What about the belt? As regards the latter it would be swell if the same belt could be used since I'm lazy and don't feel like pulling my constant speed prop, but I'd do so if that's what has to happen (or perhaps a pulley swap and obviate the effort). My PP is once again showing less than optimal voltage, probably once again due to the flakey connector. This alternator appears to have 1/4" spade terminals which I'm guessing will stay put a bit better. PP (Hartzell) doesn't even offer the alternator I have anymore; for what a replacement costs I could fill all the remaining shelf space in my hangar with these as spares..
 
Anyone know about the mounting of the Denso or in my case Bosch AL257X? Which brackets will fit? Any pictures of your mounting brackets and etc. I?m afraid I?m not in the weld up a bracket camp.
 
Depends on the alternator and we've had this discussion before. Many IR Denso alternators have 2 or 3 terminals. Take 12V off one external control terminal (usually marked IG) and charging stops:

https://www.youtube.com/watch?v=NvQRHuNpjss
Darn you and your facts and demonstrations and irrefutable evidence... Ha ha.

To be fair the IGN is not "direct" field power. It is through semil-conductor (transistor) that may indeed kill the field, but it's not providing field juice through the IGN lead. IGN is a sense lead. The drain on the IGN lead is tiny when it is running. Like most "one-wire" alternators the field power comes from the B-lead.

Many so called "ND" Alternators are not original ND but China knockoffs or "clones". The internal VR in the clones don't seem to be standard. Quality and reliability also seems to vary. Not all of them work the same in regards to the IGN lead (so I have been told and heard). One guy cycled his "IGN" off then on in flight and got a massive OV.... My ND is only 40-45 amps. The B-lead is going through a panel mounted 50 AMP Circuit breaker. The avionics bus is parallel feed with two OV relays. I recommend finding a genuine new ND. Cheers.
 
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Regarding using one of these to replace a PP alternator... I have a lathe and can likely figure out mechanical mounting details, but curious about what else is required for the swap. PP alternators have overvoltage protection built in, or so they say. Did you address that or that built in to these? What about the belt? As regards the latter it would be swell if the same belt could be used since I'm lazy and don't feel like pulling my constant speed prop, but I'd do so if that's what has to happen (or perhaps a pulley swap and obviate the effort). My PP is once again showing less than optimal voltage, probably once again due to the flakey connector. This alternator appears to have 1/4" spade terminals which I'm guessing will stay put a bit better. PP (Hartzell) doesn't even offer the alternator I have anymore; for what a replacement costs I could fill all the remaining shelf space in my hangar with these as spares..

They all have OVP built in. Supposedly. Have I verified it? No. Have I had an OV happen? Yes, on an old alternator. Haven't worried about it up to this point as all of them I've installed are not on electrically-dependent airplanes. There are many ways to skin this cat with off-the-shelf components. My rocket requires this and I have a circuit I have in mind but have not built the device yet.


I've used the same belt the PP alternator used.
 
Darn you and your facts and demonstrations and irrefutable evidence... Ha ha.

To be fair the IGN is not "direct" field power. It is through semil-conductor (transistor) that may indeed kill the field, but it's not providing field juice through the IGN lead. IGN is a sense lead. The drain on the IGN lead is tiny when it is running. Like most "one-wire" alternators the field power comes from the B-lead.

Many so called "ND" Alternators are not original ND but China knockoffs or "clones". The internal VR in the clones don't seem to be standard. Quality and reliability also seems to vary. Not all of them work the same in regards to the IGN lead (so I have been told and heard). One guy cycled his "IGN" off then on in flight and got a massive OV.... My ND is only 40-45 amps. The B-lead is going through a panel mounted 50 AMP Circuit breaker. The avionics bus is parallel feed with two OV relays. I recommend finding a genuine new ND. Cheers.

Yes, we've had extensive discussions in other threads on bad Denso clones and OEM Densos having their OEM reliability compromised by rebuilding shops inserting inferior, non-Denso regulators, brushes and bearings, which is super common unfortunately.

I recommend using the older 3 terminal (4 with B lead) Denso units.

You can watch a bench test on a one wire unit here. Removing the "field wire" stops the charging. https://www.youtube.com/watch?v=LFscQAbk5ao
 
I am running an auto alternator. For OV protection I have a relay on the B lead. The relay energizes with the master. There is a crowbar OV module in the relay coil circuit, so if I get and overvolt, the crowbar will trip the breaker for the relay and disconnect the alternator from the system.
 
They all have OVP built in. Supposedly. Have I verified it? No. Have I had an OV happen? Yes, on an old alternator. Haven't worried about it up to this point as all of them I've installed are not on electrically-dependent airplanes. There are many ways to skin this cat with off-the-shelf components. My rocket requires this and I have a circuit I have in mind but have not built the device yet.


I've used the same belt the PP alternator used.

Thanks for the info. I've witnessed two PP alternator failures (both were pre-Hartzell models, as is mine), neither in my airplane fortunately. Not a connector getting flakey, something going TU and tripping the field circuit breaker. OV protection worked in both cases on those units.
 
My alternator went bad shortly after I bought the plane 3 years ago and I went with a Duralast alternator from Autozone and couldn't be happier. Mine is a 30amp alternator. I know you're looking for a 50amp, but I'm just chiming in to say that I'm very happy with it so far.

It's paired with a Duralast voltage regulator (model number VR730) and both have lifetime warranties, and cost almost nothing compared to aviation alternators. The alternator was about $45, voltage regulator about $20.

Reliable, cheap, lifetime warranty, and almost drop in replacement (had to change the pulley - I used the one off my old alternator).
 
I went with B&C this time

My first Plane Power alternator lasted around 240 hours. It quit leaving Oshkosh several years ago. I started getting low amperage alarms on my second Plane Power just before landing at We B Smoking on the way home from Oshkosh this year. This alternator had around 510 hours on it. I bought an '87 Suzuki Samurai alternator to replace it with but it wouldn't fit my mount. So, I shelled out the big $$$ and installed a B&C and their external voltage regulator. Of course, I had to pull the constant speed prop for the new belt, (old one was eleven years old but was still in good shape with no cracks or fraying) and crawl under the panel to install the regulator. Not much fun for an old guy when it is 95 degrees out. Hopefully, I'm good to go for a long time.

My PP failure modes were completely different. The first one lost the rear bearing. It appears the second one toasted the regulator. The bearings are smooth. No issues with the connector. I tried them with and without blast tubes. Both were pre-Hartzell units.

It seems some guys are slapping the Samurai alt. on the PP mount and not even having to change the connector. It wasn't even close to lining up the pulleys for me...
 
i have never heard of an auto having its glass panel taken out by ov but i installed one similiar to colin's. my relay on the b lead is disconnected by a domino sized unit sold by perihelion, eliminating the breaker on the coil of the relay.i also have the 50 amp breaker on the panel but like another has said pulling that may fry the alternator.
 
FWIW, when I do a glass panel upgrade the aircraft goes out with a B&C installed, period.
 
Well I decided to just order the B&C.

While this is an area of interest of mine it was becoming another time sink and beginning to look like I was creating another project. The B&C alternators are a well respected product and a good alternative even if a lower cost auto alternator may work just fine too.
 
The main reason I went with an auto alternator is field replacement. If I am AOG somewhere due to the alternator, I cancatch a ride to the nearest autoparts store and be on my way in no time.
 
The main reason I went with an auto alternator is field replacement. If I am AOG somewhere due to the alternator, I cancatch a ride to the nearest autoparts store and be on my way in no time.

The main reason for a B&C is NOT having to find an auto parts store when traveling. I doubt my wife would travel with me much if I told her our planned route has to have auto parts stores along the way :eek:
 
The main reason for a B&C is NOT having to find an auto parts store when traveling. I doubt my wife would travel with me much if I told her our planned route has to have auto parts stores along the way :eek:

Also a good point. But if it does fail, now you are trying to overnight parts and are stuck. Pro/cons both ways
 
None of my now $42.49 alternators have failed on me. But I can tell you guys a story about having to spend half a day getting a B&C fixed for a friend on the way to Oshkosh. A B&C is $720.00 with the regulator. No friggin thank you.
 
Yes there is a premium for the B&C but we each have our own considerations. Time and progress are mine. BTW Wicks has a deal on the bundle right now.

I actually purchased a Bosch AL257X from Amazon for $35 and purchased the mounting kit from B&C. They would require building spacers aligning the belt and etc. Given enough time these are simple operations with a possibly good outcome. I'm certainly not disputing that.
 
Premium? For what? Its a ND alternator. Repackaged with a little bit of proprietary sprinkled on to make you THINK its better.

I replaced a B&C starter once and called them to get a set of brushes to rebuild it as a spare. They wanted over $140 for the brush parts. Took it to a friend's starter/alternator shop. When he looked at it he said it was a Mitsubishi starter motor. Had the brushes on the shelf. Fixed it and didn't charge me so I bought him lunch.
 
Bob,

I agree with most of what you've said, but our small town hasn't had an alternator repair shop for over 25 years and I had to have O'Reilly's overnight the Samurai alternator.. they didn't stock it. So those advantages of the auto alternator choice didn't work for me. I was pressed for time as my family was having a reunion in Colorado or I might have tried harder to find a way to make the PP mount work with the car alternator. It was more than just having different bushings machined. Also, I had visited the B&C booth at Oshkosh and they had a 10% off special if you purchased at the show. Even though I had a feeling the PP was overdue for failure based on reports of life expectancy on VAF, I decided to wait. Fortunately, when I called B&C and mentioned I talked to them at the show and should have bought then, they still gave me the discount. I think I paid $648 but that included the mount and regulator.

I was a little concerned that the auto alternator did not have crow bar overvoltage protection.

Both PP and B&C are way overpriced but I believe at least they are brand new and not rebuilt. We'll see how long the B&C lasts. My choice would definitely not be best for everyone but they seem to have a great reputation, and most of my flying is cross country these days so there is some comfort in reliability.

My second choice if I'd had the time would have been to try and source a regulator for the PP and reinstall it. I did take it apart and checked the brushes and they were fine.
 
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