Aircraft CCW alternators

[Paul Lee]

I am using a mini Denso 45A alternator that just went on me when I put
the whole load on it. The load is not more than about 30A but is
continuous. Had another similar size alternator quit under load. What
is the problem/solution?

Since these automotive alternators are CW rotation (the cooling fan,
not the rest of the alternator) is this the problem - or does it
matter much? Or where can I get a lightweight CCW alternator or a
replacement fan for it? Or the rated load capacities are peak and need
bigger alternator for continuous 30A?

----------------------------------
SQ2000 canard: www.abri.com/sq2000

[Jerry J. Wass]

You're probably not driving it fast enough to cool itself--They'll put out
their rated amps at a low speed, but they're used to turning quite fast in
long time operation.
Calculate the cruise rpm from the auto it came from, then on your plane---

I drove one on my lathe as fast as I could, both fwd & reverse & could
find
hardly any difference in cooling air output.

Paul Lee wrote:

> I am using a mini Denso 45A alternator that just went on me when I put
> the whole load on it. The load is not more than about 30A but is
> continuous. Had another similar size alternator quit under load. What
> is the problem/solution?
>
> Since these automotive alternators are CW rotation (the cooling fan,
> not the rest of the alternator) is this the problem - or does it
> matter much? Or where can I get a lightweight CCW alternator or a
> replacement fan for it? Or the rated load capacities are peak and need
> bigger alternator for continuous 30A?
>
> ----------------------------------
> SQ2000 canard: www.abri.com/sq2000

[Drew Dalgleish]

On Thu, 30 Sep 2004 07:06:42 -0700, "Jerry J. Wass"
> wrote:

>You're probably not driving it fast enough to cool itself--They'll put out
>their rated amps at a low speed, but they're used to turning quite fast in
>long time operation.
>Calculate the cruise rpm from the auto it came from, then on your plane---
>
>I drove one on my lathe as fast as I could, both fwd & reverse & could
>find
>hardly any difference in cooling air output.

I thought they went really fast because of the large pulley on the
flywheel. ASS sells an oversize driven pulley to slow them down. Some
people throw away the fan and instal a blast tube from the pressure
side since the fan has nowhere to draw cool air from anyway.
Drew


>Paul Lee wrote:
>
>> I am using a mini Denso 45A alternator that just went on me when I put
>> the whole load on it. The load is not more than about 30A but is
>> continuous. Had another similar size alternator quit under load. What
>> is the problem/solution?
>>
>> Since these automotive alternators are CW rotation (the cooling fan,
>> not the rest of the alternator) is this the problem - or does it
>> matter much? Or where can I get a lightweight CCW alternator or a
>> replacement fan for it? Or the rated load capacities are peak and need
>> bigger alternator for continuous 30A?
>>
>> ----------------------------------
>> SQ2000 canard: www.abri.com/sq2000
>

[Paul Lee]

Searching the web, I found that the 1983-1987 Honda Prelude 1.8L
alternator
is CCW and turns out 60A. This is the right rotation for a aircraft
engines, better capacity than my previous one and much better price
than FAA PMA stuff. I have ordered one and will try it.

----------------------------------
SQ2000 canard: www.abri.com/sq2000

(Paul Lee) wrote in message >...
> I am using a mini Denso 45A alternator that just went on me when I put
> the whole load on it. The load is not more than about 30A but is
> continuous. Had another similar size alternator quit under load. What
> is the problem/solution?
>
> Since these automotive alternators are CW rotation (the cooling fan,
> not the rest of the alternator) is this the problem - or does it
> matter much? Or where can I get a lightweight CCW alternator or a
> replacement fan for it? Or the rated load capacities are peak and need
> bigger alternator for continuous 30A?
>

[Rich S.]

"Paul Lee" > wrote in message
om...
> Searching the web, I found that the 1983-1987 Honda Prelude 1.8L
> alternator
> is CCW and turns out 60A. This is the right rotation for a aircraft
> engines, better capacity than my previous one and much better price
> than FAA PMA stuff. I have ordered one and will try it.

Will you please weigh it and let us know the result?

Rich S.

[Paul Lee]

I went this morning to get it at the auo parts store.
1. It had the wrong fan on it (CW) - guess they ran out of the correct
one and figured nobody would notice. 2. the shaft was bent so the fan
"wobled". That kind of quality turned me off and I decided to get the
60A unit from Van's.
My guess is that it weighed about 10-12lbs - plus a few oz for the
regulator.
You could probably get a decent unit if you get it from different
sources and return it until get one thats OK. But I lost my patience.

Here is a website that sells the CCW alternators.
http://replacement.autopartswarehouse.com/parts/autopartswarehouse/wizard.jsp?year=1985&make=HO&model=PRE--002&category=F&part=Alternator
and a photo showing the CCW fan:
http://img.autopartswarehouse.com/live/F4000106964ATX.JPG

"Rich S." > wrote in message >...
> "Paul Lee" > wrote in message
> om...
> > Searching the web, I found that the 1983-1987 Honda Prelude 1.8L
> > alternator
> > is CCW and turns out 60A. This is the right rotation for a aircraft
> > engines, better capacity than my previous one and much better price
> > than FAA PMA stuff. I have ordered one and will try it.
>
> Will you please weigh it and let us know the result?
>
> Rich S.

[Leon McAtee]

(Paul Lee) wrote in message >...
> Searching the web, I found that the 1983-1987 Honda Prelude 1.8L
> alternator
> is CCW and turns out 60A. This is the right rotation for a aircraft
> engines, better capacity than my previous one and much better price
> than FAA PMA stuff. I have ordered one and will try it.

You may find that there are other Honda alternators that will work as
well. Honda motors turn backwards from most FWD cars since they have
the trans on the other side. Just about any Honda alternator not run
with a serpentine belt should turn the "right" way.
====================
Leon McAtee
Still looking for Aeronca C-2/3 factory drawings......

[Rich S.]

"Paul Lee" > wrote in message
m...
>I went this morning to get it at the auo parts store.
> 1. It had the wrong fan on it (CW) - guess they ran out of the correct
> one and figured nobody would notice. 2. the shaft was bent so the fan
> "wobled". That kind of quality turned me off and I decided to get the
> 60A unit from Van's.
> My guess is that it weighed about 10-12lbs - plus a few oz for the
> regulator.

Thanks, Paul. Doesn't look like one would save enough weight to be worth the
trouble, if you already have a working stock setup.

Rich S.

[Paul Lee]

I have been playing around with several alternators before finding
which work. I now have an extra Honda (Denso style) nearly new alternator
which has the correct CCW cooling and I converted the pulley to single
grove. It is just under 10 lbs and puts out 70A. I would let
it go for $120.

--------------------------------------------------
SQ2000 canard: www.abri.com/sq2000


"Rich S." > wrote in message >...
> "Paul Lee" > wrote in message
> om...
> > Searching the web, I found that the 1983-1987 Honda Prelude 1.8L
> > alternator
> > is CCW and turns out 60A. This is the right rotation for a aircraft
> > engines, better capacity than my previous one and much better price
> > than FAA PMA stuff. I have ordered one and will try it.
>
> Will you please weigh it and let us know the result?
>
> Rich S.