Thorp Air Command - T18.net

I am trying to extend my knowledge from zero to something I can make a decision with. I find lots of experts being very vociferous either for or against automotive or aviation alternators. I think I just about understand some of the issues but am having a hard time. I wondered if there was any concensus amongst the T18. I am running an 0-290 and intend to have minimal electrics, small radio mode S couple of instruments. (UK daytime VFR only)

Thank you Dave

David,
I had a lead brick Prestolite on my airplane for a year or so, it was nothing but trouble. Prestolite's are just fine, I just had several bad experiences with mine the final being the start of a cross country with the Mrs. and a burned up alternator causing (in her mind) an "emergency landing". ... She hasn't flown with me since.

After that episode I installed a 1991 Suzuki Samaria Nippon Denso unit which I have been more that happy with. Lightweight small etc. This is the unit that Vans used to sell before they made a deal with Plane Power. They still sell the mount and plug for it though I believe. I picked up mine at the local Auto Part store for $96 (USD).

On another note, I did build up a 0-290 powered airplane a couple of years ago. It was a solid day VFR only airplane and a 55 amp alternator was just plain overkill so I went with the B&C SD-8 spline driven unit. It runs off the vac pump pad and is really slick. The B&C guys were extremely helpful and have great service. It's not cheap ($450) but it's simple in design, weighs 3.7 lbs, and is rock solid.

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Dave,

I have been running a Nippon Densu for many years. Very minimal problems. One note, however: For aircraft use, I recommend a field switch that will allow you to turn the alternator off in case of run away voltage. This situation can be bad as an overcharged battery in flight is a fire hazard. A simple switch for the field wire in the cockpit gives you the means to shut the alternator off.

_________________
Bob Highley
N711SH
SN 835
KLAL

I've got one of those large automobile alternators. I keep it because my battery box is behind my "luggage" area and I have a wood prop. I need the weight in front when I carry a couple of suitcases.

I have an electronic whine in my headset and someone told me that is an indication that the alternator is apt to have a bad diode. Anyone able to confirm that?

I believe so. The first link goes into a lot of possible causes for noise. These links may help you with your noise issues.
http://www.avionicslist.com/articles/ce ... -noise.php
http://www.flightcom.net/pdf/403mcManual.pdf
Scroll down to trouble shooting:
http://www.flightcom.net/pdf/IIsxManual.pdf

You might also have a antenna shielding issues.
Some alternator filters:
http://www.aircraftspruce.com/menus/el/ ... lters.html

_________________
Victor J Thompson
C-GIRQ
"In Memory Of Dad"

Thank you for the input
I found the following links and threads

Looks like japanese automotive is the way to go

Dave


http://www.periheliondesign.com/lovm.htm

Linear Over-Voltage Protector

monitors the voltage on the main bus (or anyplace), lights a panel-mounted warning LED when the monitored voltage rises above 16.2V for more than 200 mS and politely opens (disconnects) the alternator field circuit or B+ contactor (or whatever). A user-supplied over-ride switch (wired to E-BUS+ or battery bus) will reconnect the circuit, and if held in will even keep the circuit on

http://www.plane-power.com/

http://www.bandc.biz/index.aspx

http://www.vansairforce.com/community/s ... 510&page=3

http://img116.imageshack.us/i/altwiring5cm.jpg/

http://www.nflite.com/

http://www.vansairforce.com/community/s ... hp?t=32831

http://www.vansairforce.com/community/s ... php?t=5841

http://thorp18.com/forum/topic.asp?ARCH ... IC_ID=5928

http://vansairforce.com/community/showt ... hp?t=45843

http://www.vansairforce.com/community/s ... php?t=2884

http://www.aviationbanter.com/showthread.php?t=1171

www.matronics.com

Nipon-Denso Alternator Modifications
The following paper was submitted to the
AeroElectric.com for consideration of a technique
that reconfigures an automotive alternator to
conform with traditional aircraft philosophy for
alternator control and over voltage protection.

David,
I've got a Nippon Denso on "another" experimental as well. Cessna type switch for the master and field, and no OV relay. Is fine in what it's in, but I'd probably put in an OV relay if I had a lot of expensive avionics.

The alternator turns "backwards" from the direction in a car. Electrically it makes no difference. It turns faster than in a car, most likely, since the other pulley is larger than in a car. Also the fan turns backwards. So, the fan might better be removed, I think. I didn't worry about any of that, and don't think you should. The alternator doesn't put out much in a VFR day only ship with a good battery, so it's unlikely to cook itself, they last 100,000 miles in a car, and they're somewhat self-protecting anyway - as temperature goes up, field current goes down. There may even be overtemp protection in the built-in regulator - don't know.

It works fine.

_________________
Rich Woodcock
N114RW - T18CW

Jack,
Assuming you haven't already done this, see if you can make the whine increase and decrease with engine speed, if so, it's engine related. Turn alternator field off (assuming you have a switch) if it goes away it's alternator related. Hook a voltmeter to the main buss and with the engine running at above 1300 rpms and the battery charging, you should see no more than about 200 mvAC (.2V) on the meter. If you see more than that, most likely you've got an open diode.

P.S. -
(I just read one of the links above and they say 1 volt, not .2 volt, but they are referring to Peak to Peak, which would translate to .35 volts. I like their method better - if you have an oscilloscope)

_________________
Rich Woodcock
N114RW - T18CW

Whine in the headset ? Probably your co-pilot !

RB

Mark Landoll

I've come across this gentleman. he sells a complete package for a very competitive price. Has anybody any experience of his products?

Dave

I have bought several alternators from Mark. Very satisfied with his products. He also sells the dampener ring for you guys using a wood props.

I had one of his dampeners on my bird. Picked up a vibration. Removed it and it went away. Called him and was very unhappy with him blowing me off. I hope to have a dynamic test of my bird with and without the dampener done soon.

** admin posted for Cubes ***

_________________
Forum Administrator

I replaced the generator on my aircraft, O290, with an alternator from Mark Landoll. It appears to be a Nippon Denso unit from an 87 Suzuki Samuria. It has an internal regulator, with the field wire run from a switch on the panel and can be shut down in flight. I am very happy with this upgrade, 55 amps is more than I need but the price, $80.00usd, was right. The same unit from the local auto parts places was $140.00 with out a core. Mark also had a case mount bracket so that I just had to bolt it on and go, not to mention the "minor" wiring changes needed. [:)]

_________________
Bruce Finney
N18JF T-18C #262
Yelm, WA USA

Re B&C Spline driven alternator

I have an 0-290 G4 ex GPU, the conversion was made with (I think) an accessory case from an 0-320 (it was done in the early 1960's)so I do have the blanked off vacuum pump drive. I don't have the adaptor pad and drive gear assembly and would need to fit this. Are there any gotchas associated with putting this drive into a converted engine such as this. I am still in the process of examining all my options this is expensive but would be quite light and neat.
Thank you
Dave