Plane power alternator cooling

I searched, No Joy.
Can someone tell me which end of the alternator to direct the blast tube cooling? Some talked about the note on the installation drawing. I couldn't find any note on my drawing.
It would make sense to put the tube on the front side since PP's cooling fan rotates in the correct direction. Email sent to PP, but its Saturday, no answer expected till Monday.

Note on drawing from Plane Power's website says:

"2. Install alternator per included drawing. Supply outside ram air to rear of alternator by the use of 1? scat tube or other suitable ducting."

Hope this helps...

My plans had the note quoted above. I went so far as to call PP to ask specifically where on the rear to aim the tube and was told pretty much anywhere is fine. I aimed my blast tube toward the heat sink. FWIW, I decided that 3/4" corrugated plastic tubing was "suitable ducting".

DUH!!! I was looking on the drawing.
Thanks. Just what I needed.

Alton,
The newer ND alternators have internal fans at both the front and the rear. The front will get "some" air from the cowl inlets. It's impractical to try to supply air via a duct to that area anyway. Supply it to the rear. The fans draw air in at both the front and rear. The air is expelled via the slots around the circumference in the middle of the unit.
I've got a few photos of a very nice composite duct that David Brand made for his RV. If I can find them, I'll post them for you.
Charlie Kuss

Thanks Charlie. I am getting down to the small details and this is one of them.

David Brand's solution

Alton,
Here are four photos of a very nice duct that David Brand designed for his alternator. The installation looks unusual because David has a Franklin 6 cylinder in his RV. That said, it's the same style Nippon Denso alternator.









Charlie Kuss

Blast tube

Hi.

I contacted PP about this awhile ago, and they told me the blast-tube wasn't really necessary.

I wrote them because I was concerned about the water-spray the cooling hose will direct into the alternator when flying through rain.

They also told me the rain was no problem.

To be on the safe side, I installed a blast-tube (I used the black Vans tube) per drawings but placed the blasttube in a "U"-shape below and before entering the alternator.
In the bottom of the "U", I cut a small hole so the water can flow out.

Heat shield on exhaust!

ao.frog said:

Hi.

I contacted PP about this awhile ago, and they told me the blast-tube wasn't really necessary.

Click to expand...

You can find a lot of discussion about this subject here on the forums. A lot of members will remember good old "George", who would love to go in discussion about this.

I looked at my Lexus and did not see a blast tube. Since it is in quite a hot area as well, I figured if the alternator in my car can stand the abuse of me running with the headlights on day and night, aircon on all the time, electric heated windows, mirrors, seats, GPS, Radio-DVD, etc. etc. for over 290.000 km, it will be fine in the plane as well. I do not intend to run it as hard as the one in the car either. I have a back-up alternator as well, anyway.

What I figured would help a lot, is the heat shield that I installed on the exhaust pipes that are righ behind the alternator!

You are the builder, do what you think is necessary.

Regards, Tonny.

Just to update

Here is what I got from Plane Power:

Hello Alton,

Thank you for purchasing one of our Experimental Alternator Kits.

The blast tube is not necessary for operation as long as your maximum continuous load is not the maximum rated output of the alternator. If you plan on pulling a constant 60 amp load then I would suggest running the blast tube, otherwise the alternator will cool fine without any additional cooling.

Best Regards,
Billy Jowers
[email protected]