Greetings . . . more under hood details to share.
The folks at PowerGen do a great job of hiding a one wire alternator inside a case that looks very much like a Delco generator
PowerGen GM long Case image Their
#80257 is an internally regulated 6-volt one-wire alternator that puts out 54 amps at idle – 58 at cruise – and maxes out at 65 amps. The voltage regulator setpoint is 7.3 volts. So my trusty Simpson voltmeter tells me at a glance whether I am running solely on battery power (6v) or the output of the PowerGen (+7v). This always-on-tap amperage allowed me to fit a 12-volt 10amp voltage booster to power modern accessories like a stereo-radio conversion and a cigarette lighter outlet that can run & charge modern gizmos . . .
The challenge for me is that the folks at Rhode Island Wiring Service:
RIwire do an equally good job of reproducing a stock wiring harness for these old Chevrolet’s. Seemed a total waste to just ‘tape-off’ a brand new set of lugged copper conductors just because the one-wire alternator doesn’t need them. So I slept on the dilemma and decided that these ‘un-needed’ wires were perhaps candidates for re-purposing.
The installation instructions for the PowerGen unit call for a single heavy gauge charging-wire routed to the battery + post, as well as, an equally heavy gauge wire grounding the PowerGen case to the engine block. My sleep therapy suggested that the least conspicuous place to connect with the battery + terminal was the starter post. So I ordered an 8 gauge cloth covered wire from YnZs:
YNZ it runs directly from the ‘battery’ terminal on the PowerGen over to the primary starter post – with a brief visit through the passenger compartment. This is essentially a direct shunt from the alternator to the battery – completely bi-passing the dash mounted Ammeter . . .
This got me to thinking (and sleeping on) how to repurpose the stock ‘charging circuit’ wiring in a useful way. I no longer needed the old external Napa “Echlin” voltage regulator – except that my beautiful new RI wiring harness had three wires ready to attach to its terminals . . .
The answer turned out to be quite simple: gut the VR and turn it into a semi-functional prop.
These old voltage regulators contain electromagnetic relays that open and close in order to make-and-break the charging circuit between the generator and the battery. The dash mounted Ammeter tells the operator the extent & direction of current flow – i.e. whether the car is currently running-on (and thereby) discharging the battery or if the charging-circuit is magnetically engaged and therefore the generator is charging the battery.
Eliminating the relays in the VR seemed like an easy proposition at first – just drill out the rivets! The trouble is that the bus bars also depend on these insulated-rivets to affix them to the VR base and therein provide structural support to the screw terminals for the wiring harness.
Those old rivets had to be replaced with insulated screws in order to retain the terminal posts – but isolated from ground. Nylon bushings and washers do the job nicely. A short section of the old 10 gauge Ammeter wire (cut from the old harness) acts as a shunt from the GEN terminal to the BAT terminal. The BAT terminal connects to the stock-harness’ charging circuit wire that runs to the dash mounted Ammeter onto the main battery bus wire that in turn terminates on the hot starter post:
This provides two paths to the battery for the PowerGen – an 8 gauge and a 10 gauge wire – the second/stock path allows the Ammeter to function normally showing charge/discharge current flow . . .
Which leads us to the elephant under the hood . . . while the internals of the gutted VR are all hidden from sight by its metal cover: what does one do with the ARM and FIELD wires that are normally attached to threaded posts prominently visible on the generator case?
More sleep therapy suggested another simple answer: recreate the A and F posts . . .
The ‘A’ Armature post terminates the heavy wire in the stock charging circuit – it is normally attached the + insulated brush running on the generator armature. In this application it needs to be attached the ‘Battery’ post of the PowerGen – which is already occupied by the primary 8 gauge charging wire. The ‘F’ Field coil post is totally unnecessary (with a gutted VR) . . . perhaps it could just be used as an additional ground wire?
There is a case bolt in close proximity to the Battery terminal on the PowerGen. In fact I used it to ground the PowerGen to the engine block when I installed the unit.
These observations were the inspiration for an epoxy wrought case-extension that roughly recreates the A and F posts normally found on a Delco generator. A rectangular blister pack acts as the mold for the epoxy.
It starts with a hand filed brass lug to create a second ‘hot’ post for the ‘Gen’ wire in the stock harness. The flat brass stock is drilled and tapped to retain a brass screw. The head of the screw is ground off once it is secured with a jam nut. The blister pack is half filled with #7 fifteen-minute epoxy. By making the hole just large enough to thread the screw through the plastic – the epoxy cannot leak around it. Applying heat with a heat gun forces all the bubbles out of the epoxy pour and makes for a rock solid cure. The plastic of the blister pack forms the final shape/surface of the case extension.
Mounting the case extension on the PowerGen was completed using another section of flat brass with a 90-degree bend. The short end of the bend is drilled so that the upper case bolt can pass through.
The long end of this bit of brass secures the faux ‘Field’ post and provides a large area for a second pour of #7 to bond. The second post is attached by drilling and tapping the previously cured epoxy.
The second pour filled the blister pack completely. The perimeter of the bar is completed by placing masking tape around the bar and performing a third pour. Once cured the masking tape is removed and the bar can be sanded smooth for finish on top – and rough sanded on the bottom for tight fit to the PowerGen case.
The resulting terminal post bar is then primed and painted black – and then masked for base perimeter painting in sliver (to match the end case caps). With fiber washers placed over each post the case extension is complete:
To install the extension one need only pull the upper case bolt and drop the A/F epoxy bar into position with the ‘A’ eyelet on the ‘Battery’ terminal of the PowerGen. Reinstalling the case bolt snugs the extension firmly in place. The nut that secures the main charging wire to the ‘Battery’ post provides additional anchorage. The result is a three wire affair sure to invoke questions when the hood is up:
I turned 100 miles on the odometer today! Tuning and tweaking continues.
regards,
stock49
