My automotive alternator has not failed in over 700 hours but have had one belt failure at 540 hours and a completely cracked through attachment bracket at 680 hours.
Both failures make we suspect misalignment issues so spent more time ensure true planar drive off the engine when I replaced the bracket. Bearings in alternator still seem good.

400 hours on my B and C 60 ampere. Zero failures.

I wish that I could vote twice because the RV-6 that I fly lost it's automotive alternator at 60 hours.

That is what convinced me into going with the B and C for the -7!

I just installed their starter. I love it too!

;) CJ

ND failure
 

ND Alternator, supplied in Van's FF kit.
Voltage regulator showing signs of failure after 7 years with 460 hours. Was displaying up to 16 volts on GRT EIS.
Installed on O-320 with blast tube.

Replacing with PP but now questioning that decision based on comments in this thread and others.

Comments on the latter welcome.

B&C 40A. No failures. 15 years/1000+ hours.

No blast tube.

B&C
 

After having tried automotive alternators on my RV-4 in the early 80's and having too many failures I have only used B&C on subsequent airplanes, with no failures. That's lover 4000 RV hours that I know of, with 1100 on the current RV-10.

Vic

my plane was born with a 87 suzuki samuri alternator and still lives with one. i have a spare one on hand that travels with me, also a starter too, and the warranty is still in effect. at times a have had one or the other rebuilt for $100 but that is the way it is. each to his own.

B&C 60A 1800hrs. Added water to the voltage regulator which it didn't like but worked after dried out. At about 1500hrs, mystery field wire issue, never found root cause. Replaced entire field wire and connector for resolution. Claiming no alternator failures.

I had a brand new internal regulated Nippondenso for the Suzuki Samuri fail at 79 hours. Had a cooling blast tube and never flown in rain. Replaced with B&C external regulated.

I realized last night that the PP 60A alternator in my plane has been the least reliable component in the plane. Not what I would have expected.
Two failures in 450 hours. (I do have a cooling blast tube on the regulator)

First failed at 85 hours.
Second failed at 365 hours.

Called PP today and they DO NOT repair their alternators. They direct you to buy another at one of their vendors...
Going to try try the local repair shop, or bust it open myself. Nothing to lose.

87 Suzuki Samurai alternator in my -9A with no failures in the ~400 hours that I flew it.