SD-8 Alternator

[GaryK]

Bill,
Here's a picture of the SD-8 on a 0-360 during installation. I didn't use the tach drive for my GRT EIS.

Gary

[mgomez]

Originally Posted by szicree

Anybody using the B&C SD-8 alternator as their only source of juice? If so, what sort of electrical equipment have you got? I'm building a Day-VFR plane and am thinking this approach might work real well.

Steve Zicree

I too was thinking of using the SD-8 to power my essential bus. I have installed two batteries, and plan on two alternators, two regulators, etc...in other words two separate electrical systems. I would like to be able to parallel the batteries for starting so the ess bus's battery will discharge a bit. The essential generator needs to be able to charge it. So I decided the SD-8 was a bit small, and was thinking of the SD-20. It's heavier, but the SD-8 was barely earning its way onto the airplane.

Cheers,
Martin

[Rick_A]

I inquired about the supplenator a while back and don't remember the exact price, but it was a lot more expensive than any of the B&C alternators.

[Bill Palmer]

Thank You, Russ and Gary, for your SD-8 install pictures!

It looks like the SD-8 orange housing is a little too close to the tach drive to install a 90-degree adapter, or sender, directly to the drive. On the other hand, it looks like there's enough clearance to install a tach cable. So that's what I'll do: run a tach cable from the tach drive to a firewall-mounted sender.

Thanks Again!

Bill

[Boyd Birchler]

On acro planes we all used the SD8. Kept everything going, never saw any problems,but we did not have much equipment.

[eaglen92ce]

I had an SD8 on my Christen Eagle and it had no problem keeping up with the electrical loads of that airplane.

SL40 comm
GTX327 Xpdr
PM3000 Intercom
Garmin 196 on ships power
Fuel flow computer
No lights

[rv8ch]

Old thread, but it seems technology is moving forward. B&C now have a much wider range of beautiful gear driven alternators.



Seems like a better way to do it, although a bit more expensive.

I'll probably go this way if my current alternator fails.

[Larry DeCamp]

The SD- on the top vac pad will not clear the tach cable signal generator supplied by Vans. I did not want a cable to the firewall so I built a short aluminum extension tube and drive cable to clear the SD-8.

Power demand flying is:
Battery contactor
Vans steam gauges 4
Mgl digital gauges 3
Fuel computor/ red cube 1
MGL V6 radio
Ifly 740 gps
Tip stobes 2

Always shows 14.2 volts at 2,300 RPM

[airguy]

Originally Posted by rv8ch

Old thread, but it seems technology is moving forward. B&C now have a much wider range of beautiful gear driven alternators.



Seems like a better way to do it, although a bit more expensive.

I'll probably go this way if my current alternator fails.

This is what I'm running for my backup alternator on my vacuum pad, and it handles all flight loads just fine at normal flying RPM. That's dual Dynon, 430W, Lightspeed Plasma, and electric fuel pump in place of engine-driven. If I bring landing/strobe/nav lights online and pull the power below 1800 rpm then my voltage drops and the battery starts to contribute.

[gmcjetpilot]

I have researched this, even the larger pad mounted alternators do not make much more than 10 amps at idle. The weight savings is not that grea,t and there is a possible issue of shearing the spline drive (which can happen apparently). Also heat in the back of engine compartment might lower longevity of alternator?

Belt driven fwd alternator will make more power at all RPM's. and the extra weight of the brackets and belt is not that much. It should also be cooler up front then off the accessory pad off the back of the engine. Also the belt absorbs the power pulses of the engine. Vibration will not help an alternator but if you have good LORD mounts and balanced prop you should be OK there.

With that said a pad mounted alternator as your only source of power is an option. It will save some weight and move CG aft. If going B&C it will be expensive, plus cost of external voltage regulator. Plane Power has a pad mounted option with internal voltage regulator. Just be aware you are not going to be making much power to charge the battery and run electronic ignition, avionics and lights and iand...