What's this alternator-starter brace/bracket for?

Having just learned like many others that once a Plane Power fails out of warranty that they have no interest in fixing it (even at customer expense) but instead tell you that you need to buy a new one, I've decided to seriously consider going the automotive route. (Still investigating a local repair shop to fix the PP, but not too hopeful yet that I will be confident in it even if it does get fixed. And yes, I have thought about a B&C but not ready to spend that kind of $$ now.)

However, before I make the switch, I need to know what this brace between the starter and alternator is for. Since the starter is solidly connected to the engine case by four large bolts, the brace seems like its just along for the ride.



Will I need to account for the brace and connect it the different alternator mount bracket (Van's still apparently provides these for automotive style alternators) or can I safely leave it off without ill-effect to either the starter or alternator?


Thanks.

That brace is designed to support the forward of the starter drive housing. I have seen many starters with the attachment lug broken that still function, but I wouldn't leave it off. FYI the primary cause of the starter boss cracking is due to the tie strap being loaded because it was not shimmed correctly with washers during installation.

What was the failure with the PlanePower unit?

Brace

I wouldn't leave it off. I once removed a Mooney engine for crankcase crack repair. It had no brace and a Bendix the would engage roughly. Ended up with a 7" crack that originated at a starter mounting bolt on left case half.


Don Broussard

RV 9. Rebuild in Progress.

OK. Sound like I'll plan on fabricating a new brace in the event the new alternator bracket can't use the existing one.

Mike H said:

What was the failure with the PlanePower unit?

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Over the four years the plane has been flying, I've had intermittent alt field breaker trips on startup that couldn't always be replicated enough to troubleshoot. Then last week while in flight the volts started going up and down with engine rpm. Dynon low voltage warnings on continually while in pattern at lower rpms. (Would go off if I increased rpms.) Checked plug in back of alternator (which was a previous unrelated problem) but nice and tight this time. Called PP and they said it sounded pretty much like a problem that they've seen "a few times."

I would take the alternator to an automotive alternator shop and have it repaired. Very inexpensive to repair and it should be good as new. You may want to install a new connector plug if you repair the alternator since the contacts in the old plug may be getting worn. If you do not want to repair that alternator and want to use an externally regulated unit, it shouldn't be hard to cross reference an application for a Nippon Denso alternator that uses the same size case and mounting points. I bet someone at the alternator shop could even help you with this. If you decide to go externally regulated I would suggest a B&C regulator and over voltage relay, or a Zeftronics combination regulator with built in over voltage protection.

I called up B&C to see why I didn't get the brace with my B&C alternator and ended up speaking to Bill. He explained that vibrations from an out-of-balance alternator causes premature cracking of the primary alternator adjustment bracket. He went on to say B&C is the only alternator manufacturer that dynamically balances their alternators, thus they do not require installation of the brace. That made me kind of happy to know that my gut feel about the good quality of the B&C alternator had been borne out in fact.

Canadian_JOY said:

I called up B&C to see why I didn't get the brace with my B&C alternator and ended up speaking to Bill. He explained that vibrations from an out-of-balance alternator causes premature cracking of the primary alternator adjustment bracket. He went on to say B&C is the only alternator manufacturer that dynamically balances their alternators, thus they do not require installation of the brace. That made me kind of happy to know that my gut feel about the good quality of the B&C alternator had been borne out in fact.

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Not true if you have a case mount alternator.

The hefty B&C bracket has a built-in portion (not a separate strap) that connects to the starter.



This is a side shot, but the bolt head you can see goes into the threaded "ear" of the SkyTec starter.

I currently have what I believe is a boss mount. It bolts up flat onto the bottom of the engine case. However, it is it also possible that I could use a case mount if someone had a bracket they were willing to part with?

I have to check on Monday, but Van's no longer carries at least one of the two types--I just have to confirm which it is and,if in fact, they at least carry the other style..

Mike H said:

I would take the alternator to an automotive alternator shop and have it repaired. Very inexpensive to repair and it should be good as new. You may want to install a new connector plug if you repair the alternator since the contacts in the old plug may be getting worn. If you do not want to repair that alternator and want to use an externally regulated unit, it shouldn't be hard to cross reference an application for a Nippon Denso alternator that uses the same size case and mounting points. I bet someone at the alternator shop could even help you with this. If you decide to go externally regulated I would suggest a B&C regulator and over voltage relay, or a Zeftronics combination regulator with built in over voltage protection.

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Thanks Mike. That's been part of my plan IF I can find someone willing to work on an aircraft alternator. The first couple I called said they couldn't /wouldn't work with a/c alternators.

alpinelakespilot2000 said:

Thanks Mike. That's been part of my plan IF I can find someone willing to work on an aircraft alternator. The first couple I called said they couldn't /wouldn't work with a/c alternators.

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I thought you meant to say the alternator off of your boat? hint, hint. ;-)

kevinh said:

I thought you meant to say the alternator off of your boat? hint, hint. ;-)

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Yes. It was from my "RV" but the Plane Power written on the side told them what kind!

It sounds like your voltage regulater is bad.
You can replace that yourself with out too much difficulty.
If you remove the back cover from the alternator, which is just a few screws, you can remove the VR and just get another one like it.
To get an idea of what it looks like, if you haven't seen one, Google voltage regulator Nippondenso.
The VRwill hav a part number on it that you can search the web for and order or if you're lucky a local shop will have one. Cost is typically around $30 or so.

sf3543 said:

It sounds like your voltage regulater is bad.
You can replace that yourself with out too much difficulty.
If you remove the back cover from the alternator, which is just a few screws, you can remove the VR and just get another one like it.
To get an idea of what it looks like, if you haven't seen one, Google voltage regulator Nippondenso.
The VRwill hav a part number on it that you can search the web for and order or if you're lucky a local shop will have one. Cost is typically around $30 or so.

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Try looking at the 1997 toyota paseo. It has the 100mm stator, the right plug, the right front housing clock. The internals might be the same.

On the negative, the rear housing should be reclocked to the right 90 deg, the pulley replaced, and the rear housing mount ear cut off to be a correct fit. It is sold as a 60 and 70 amp version.

Clocking and housings are off, but let us know of the regulator, stator, rotor, and rectifier bridge are the same. I "think" they are IF the stator rotates with the rear housing clock position.

Report back.

If this one works, we can have a good quick backup for the 60A PP. Although without OV protection.

Edit: http://www.wagneralt.com/products/W105-20.asp This seems to be the right stator for the 60A PP. It is certainly the right dimensions, although it says 45 amps. If you go to the shop get them to compare to the Paseo, and CAT OR4327 alternator (55A, 100mm OD stator). Being Cat it might be more durable, or being BCP selected it might not.