Biting The Bullitt’s Powermaster 140 Amp Alternator Upgrade


Since equipping Project Biting the Bullitt with a specially-built 427ci Dart engine, we’ve seen a lot of great things happen to our ’65 Mustang, and we’ve also hit some bumps along the road. Pushing over 500hp out of the engine naturally aspirated and 1,000 horse on 16psi of boost can take its toll on components rather fast. In our case, it was Biting the Bullitt’s alternator that gave out just a short 100 miles after the new engine went in. But, just like with every project vehicle, when something breaks, it makes room for even more improvements. That’s why this time around we opted for a Powermaster Performance race alternator.

Replacing a 1G or 2G Alternator

IMG_8502Classic Fords like our ’65 Mustang came with 1G and 2G alternators straight from the factory. However, with new technology and mass modifications, true 2G alternators have kind of fizzled out. Luckily, there are plenty of options to replace your stock alternator with an upgraded piece from Powermaster.

“The 2G Ford alternator was very revolutionary for it’s time, but as amperage loads increased on vehicles, and modifications were made, the 2G was quickly insufficient,” Brady Basner, Technical and Marketing Assistant at Powermaster, told us in a recent email conversation.

“Powermaster builds upgraded alternators to fit in the stock Ford brackets of the 1G and 2G equipped vehicles but use a one wire hookup to avoid the problematic Ford wiring of the time.”

Direct-fit 1G and 2G alternator replacement options from Powermaster include the 8-37140, 8-47140, 8-57140 and the 8-67140 series alternators. In order, these refer to chrome, natural, black and polished finishes, as well as regular, street and two race options. Each series also comes with an available pulley, like the v-pulley our Mustang came with originally. With pulleys, the appropriate part numbers are rendered with a 1 as the last digit rather than a zero.


The Perfect Fit for Biting the Bullitt

Because Project Biting the Bullitt has received a highly upgraded engine compared to its stock digs from 1965, we weren’t worried about getting an alternator with the extra pulley. But because of the amount of horsepower we’re pushing and the whole purpose behind our race-built ‘Stang, we did have to worry about choosing an alternator that would hold up to the toughest of duties. That’s why we opted for the top-of-the-line race alternator (8-67140) from Powermaster.

IMG_8497The 8-67140 race alternator offers a Powermaster-rated 140amps of power at highway speeds as well as 80 amps of power at idle. Because of this, Basner told us that the 8-67140 alternator is perfect for any pre-1994 Ford with increased power demands.

“The Powermaster 8-67140 is a completely new 140 amp alternator, made in West Chicago, Illinois with the best available copper, steel, and aluminum available,” explained Basner.

And just like all the alternators that Powermaster offers, it was developed through a long evolution process by company engineers who know and understand the vehicles that the alternators will be used on.

“When first built, it (the 8-67140 alternator) was intended to be a good looking polished, one-wire alternator for people building a street rod with a Ford engine,” Bosner said. “With the huge popularity of the Fox body Mustang in the drag racing world, the alternator quickly found it’s way to the strip. Through our tech lines and engineers, we were able to see this trend and begin building these alternators to handle the abuse of racing.”

IMG_8490So what makes the 8-67140 alternator one of the best on the market for handling the stresses of the track? Well, in addition to a one-wire design, which eliminates the pesky “catch on fire” vintage 1G and 2G designs, the 8-67140 alternator offers a custom Powermaster case, gold battery post for a better electrical connection, six-groove serpentine pulley, heavy duty 8 AWG charge wire, internal regulator system with 1-wire hookup, and 12-volt capabilities. It’s also treated to Powermaster’s unique balancing.

“Powermaster balances the rotor shafts on all alternators independent of the rest of the unit, and then balances again as an entire assembly,” Basner told us. “With this precision balancing, we are able to keep the copper and steel in the rotor that gives the 8-67140, and all Powermaster alternators, exceptional output at idle, and allow for high RPM use.”

IMG_5714Fitting Our Mustang with Powermaster’s Latest Race Alternator

Before tying our new alternator to Biting the Bullitt’s high-performance engine, we had to remove the old alternator that quit on us. By disconnecting a few wires and unbolting the alternator, we were able to complete this task in a matter of minutes.

IMG_5720Once the old alternator was out, it was in with the new Powermaster unit. After checking for anything in the way, we dropped our 8-67140 alternator in and bolted it in place. With the bolts secured but not tightened, we moved on to check for proper belt alignment. Once that was set, we adjusted the belt tension by tightening the belt tension bolt.

From there, we tightened all the alternator bolts, firmly securing it in place before hooking up the new one-wire system.

As a one-wire alternator, our new 8-67140 unit didn’t require any jumpers from the internal regulator to the alternator’s battery post. So all we had to do was run a single wire from the alternator’s output terminal to the positive post on our fully charged battery. We then reconnected our battery’s ground cable.

Using an amp meter, we finished off our Powermaster race alternator install by checking the voltage of our battery at the positive and ground posts. 

Installing the new Powermaster race alternator was one of the simpler tasks we've done to our 1965 Mustang project car.

IMG_5750Performance We Can Count On

While our 8-67140 race alternator came with a factory rating of 140 amps at highway speeds and 80 amps at idle, the Proof of Performance tag attached to our alternator reflected a slightly higher rating- one that brought the amps up at highway speeds or 7,500rpm to 153 and idle or amps at 2,400rpm to 90.

With the new alternator in place, it’s now only a matter of time before we go romp the heck out of our project Mustang. Be sure to stay tuned for our first official run with Biting the Bullitt and more upgrades to come!


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About the author

Lindsey Fisher

Lindsey is a freelance writer and lover of anything with a rumble. Hot rods, muscle cars, motorcycles - she's owned and driven it all. When she's not busy writing about them, she's out in her garage wrenching away. Who doesn't love a tech-savy gal that knows her way around a garage?
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