First time poster

[bcash4039]

glenn

The car that I am going to put this on is a 2000 Chevy metro. The exterminated MPG of the car new was 37 mpg. Which is what I got with the car two years ago. I am currently getting 46 mpg in the winter and 52 mpg summer. I switched to synthetic oil, I heat the fuel, and incoming air in the winter time. I use a scan gauge to monitor fuel mileage, air temps, water temps, voltage, etc. Also have a air fuel ratio gauge to monitor that. I would be very happy to get above 70 mpg , or at least that’s my goal.

[bcash4039]

[kumaran]

[bcash4039]

[kumaran]

[bcash4039]

[bcash4039]

[SeaMonkey]

[mrgalleria]

[bcash4039]

[bcash4039]

[glenn_aircooled]

[SeaMonkey]

Bcash4039,

Upon reflection, and with the additional symptoms you revealed regarding your alternator: It may be that the graphite brushes in the brush assembly have worn down.

With the mileage you have on your car it's probable. As the brushes wear down over the years of running, the graphite tends to build up in the vicinity of the brushes and the slip rings which may result in additional current paths. As the brushes reach the end of their lives they'll make very light and intermittent contact with the slip rings so the alternator output will be as you've described.

The brush assemblies may be replaced as a unit, or if you have electrical soldering skills, the individual brushes may be unsoldered and replaced.

Removing the brush assembly for inspection is fairly easy. Often it's a whole lot more difficult to get the alternator out.

If it's just the brushes you'll be able to repair it easily.

The diode arrays are very rugged and ordinarily do not burn out unless the alternator output has been severely overloaded or short circuited.

[bcash4039]

Seamonkey

Thanks I think that am going to replace this alternator with one of about a 100 amps, but i think i am going to have this one rebuilt for bench testing. Yes with this car it is going to very hard to get it off.

[glenn_aircooled]

Bcash4039, whilst awaiting the Alternator, could you try increasing the
concentration. From memory you are at 25% solution with Potassium Hydroxide. KOH .
You havent got much room to increase as you dont want to go above
27 % but you may as well increase it to see if you can lift the output a little.
You will hopefully find that with a good Alternator , you can squeeze just
a little more Volts through. I would expect 13.8 V. Both this slight increase in voltage and the
slight increase in concentration will up your out put. It is interesting to see
how a small voltage change at the " Knee " point of the graph can make a significant
difference to the output. The " knee " point I call it , is at around 13.4 V
. Around this voltage - the graph of Current Vs Voltage does not act linearly.
This is because the voltage per cell is at the point of moving toward an
Inefficient reaction...... but more output .
Keep us informed.
Glenn.