Problem with auto alternators

One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.

On 23 Jul 2006 21:21:19 -0700, "abripl"
wrote:

One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.


Are you telling me that all the aircraft versions of alternators have
left hand threads? Or even that alternators on engines that run
"backwards" or have the alternator on the back of the engine(like on a
Renault R12) have left hand threaded rotors?
I'm afraid I'd have to dissagree. Not ALL do. Perhaps SOME.
On counter-rotating marine engines, both alternators are the same.

--
Posted via a free Usenet account from http://www.teranews.com

clare wrote:
On 23 Jul 2006 21:21:19 -0700, "abripl"
wrote:

One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.


Are you telling me that all the aircraft versions of alternators have
left hand threads? Or even that alternators on engines that run
"backwards" or have the alternator on the back of the engine(like on a
Renault R12) have left hand threaded rotors?
I'm afraid I'd have to dissagree. Not ALL do. Perhaps SOME.
On counter-rotating marine engines, both alternators are the same.

--
Posted via a free Usenet account from http://www.teranews.com

They're all right-hand thread, even when used on a Lycoming and
turning "backwards." The fan has straight fins rather than the angled
fins found on some auto alternators.
I ran an alternator backwards on my inboard boat for years,
since there was no room alongside the engine for it and it had to go
out front and sit backwards and therefore turn the "wrong" way. The
thread never came loose, and the fan had straight fins that I got off
some alternator in the junkyard. Some cars had them that way.

Dan

clare at snyder.on.ca wrote:
On 23 Jul 2006 21:21:19 -0700, "abripl"
wrote:


One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.



Are you telling me that all the aircraft versions of alternators have
left hand threads? Or even that alternators on engines that run
"backwards" or have the alternator on the back of the engine(like on a
Renault R12) have left hand threaded rotors?
I'm afraid I'd have to dissagree. Not ALL do. Perhaps SOME.
On counter-rotating marine engines, both alternators are the same.

Corvairs do--both the old generators and the newer alternators. some
loc-tite goes a Loong way in these situations..Jerry

On Mon, 24 Jul 2006 21:42:43 GMT, jerry wass
wrote:

clare at snyder.on.ca wrote:
On 23 Jul 2006 21:21:19 -0700, "abripl"
wrote:


One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.



Are you telling me that all the aircraft versions of alternators have
left hand threads? Or even that alternators on engines that run
"backwards" or have the alternator on the back of the engine(like on a
Renault R12) have left hand threaded rotors?
I'm afraid I'd have to dissagree. Not ALL do. Perhaps SOME.
On counter-rotating marine engines, both alternators are the same.

Corvairs do--both the old generators and the newer alternators. some
loc-tite goes a Loong way in these situations..Jerry

Corvair has left hand thread on alternator????? None that I've seen,
and the manual does not mention it - and the rotor is the same as any
other Delcotron.


--
Posted via a free Usenet account from http://www.teranews.com

clare at snyder.on.ca wrote in message
...
On Mon, 24 Jul 2006 21:42:43 GMT, jerry wass
wrote:

clare at snyder.on.ca wrote:
On 23 Jul 2006 21:21:19 -0700, "abripl"
wrote:


One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.



Are you telling me that all the aircraft versions of alternators have
left hand threads? Or even that alternators on engines that run
"backwards" or have the alternator on the back of the engine(like on a
Renault R12) have left hand threaded rotors?
I'm afraid I'd have to dissagree. Not ALL do. Perhaps SOME.
On counter-rotating marine engines, both alternators are the same.

Corvairs do--both the old generators and the newer alternators. some
loc-tite goes a Loong way in these situations..Jerry

Corvair has left hand thread on alternator????? None that I've seen,
and the manual does not mention it - and the rotor is the same as any
other Delcotron.


--
Posted via a free Usenet account from http://www.teranews.com


I really doubt that there were any left hand threads on small alternators,
but there were a number of auto engines that rotated in the opposite
direction. IIRC rear drive Chryslers used to rotate backward of GM, and I
believe that Honda currently rotates the reverse of most other front drives
due to the reversed position of the engine and drive train.

I hope this helps. It should at least net an appropriate fan.

Peter

"Peter Dohm" wrote in
t...

I really doubt that there were any left hand threads on small alternators,
but there were a number of auto engines that rotated in the opposite
direction. IIRC rear drive Chryslers used to rotate backward of GM, and I
believe that Honda currently rotates the reverse of most other front
drives
due to the reversed position of the engine and drive train.

Majority of the world's automotive engines rotate clockwise then viewed from
the accessory end. Chrysler and GM engines (small and big blocks) as well as
AMC, Ford etc. do rotate the same direction. In fact I don't know any auto
engines running counterclockwise, but that doesn't mean they don't exist.

JP

On installations with rear mount alternators like Cont io/o 470s
in Skylanes, and such, the alternator turns backwards. There
is a special pulley with the fan fins in the opposite direction.

If you use automotive stuff, you will find that the fins are
backwards and the centerline of the belt is about 1/8" farther
from the alternator case than it is on the aircraft one.

Needless to say, the alternator could care less which
direction it is turning.

Bill Hale A&P

abripl wrote:
One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.

I had a ski buddy in the 50's that had a 2-cycle Saab. He liked to park
uphill and coast backward in a forward gear and pop the clutch. Then he had
several reverse gears and one forward.

It reminds me of my favorite episode on "Candid Camera." They had a
beautiful buxom blonde trying to park a big car in a supermarket parking
lot. She was having problems and would ask men to help her park. Well, these
guys would swagger up to help the poor miss out, except, the crew had
reversed the steering somehow......so left was right. It was hilarious.

Karl
"Curator" N185KG


" wrote in message
oups.com...
On installations with rear mount alternators like Cont io/o 470s
in Skylanes, and such, the alternator turns backwards. There
is a special pulley with the fan fins in the opposite direction.

If you use automotive stuff, you will find that the fins are
backwards and the centerline of the belt is about 1/8" farther
from the alternator case than it is on the aircraft one.

Needless to say, the alternator could care less which
direction it is turning.

Bill Hale A&P

abripl wrote:
One known problem is that aircraft engines turn CCW looking at the prop
but auto alternators have cooling fins optimized for CW. But thats not
apparently as much a problem as the pulley nut potentially comming
loose. For CW rotation the engine torque will tend to tighten the
pulley nut but for CCW it will tend to loosen it. It happened to me
today )on the ground) after 60 hours of use and the alternator was not
charging just spinning the pulley. Make sure you check your pulley nut
tightness ocassionally if you are using an auto alternator.