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Bryan Irons photos
Stinky Jeep - MSD
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Bryan Irons photos
Stinky Jeep - MSD
1. The overachievers at MSD actually managed to belt out 170 Amps from a 160 Amps unit. We wish this trend would continue in other places in life…
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Bryan Irons photos
Stinky Jeep - MSD
2. A standard V belt pulley or a 6-rib serpentine version is available. Apparently, the show chrome we ordered here is optional. Doh!
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Bryan Irons photos
Stinky Jeep - MSD
3. With a simple visual inspection, you would be hard pressed to guess the new alternator is rated for an extra 40 Amps over the old one. We could tell just by looking at the rear bearing part number that it is an easily sourced unit should anything happen.
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Bryan Irons photos
Alternator Autopsy
4. Our alternator autopsy showed that everything was destroyed. The electronics package including the rectifier, brush holders, regulator and man terminal connections were melted… and stunk.
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Bryan Irons photos
Alternator Autopsy
5. The spinning rotor assembly and slip rings are supposed to be a nice copper colour with the rotor windings having an insulating varnish on them. What varnish that hadn’t oozed from the bottom of our rig was flung around the engine compartment… think “Manure Spreader.”
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Bryan Irons photos
Alternator Autopsy
6. Somehow, the insulation on the stator coils got to go on a vacation and left the windings to short out wherever they pleased. FYI, this is bad.
Story & photos by Bryan Irons
Where There’s Smoke … Stinky Jeep gets some extra Amps thanks to MSD
The line “some days you’re the dog, some days you’re the fire hydrant” came to mind on a sunny afternoon while taking Stinky Jeep (our trail rig) in for a forced windshield change. We noticed our battery voltage running on the low side of normal; this means fewer than 12-volts. The Dakota Digital instruments are normally rock solid and have been exceedingly accurate in the past, so not likely the culprit. The battery was a fresh Odyssey unit and our prior experience tells us that they are as reliable as an anvil – again - probably not the cause of our concern. However, the issue would become clear with a single sniff of the nose. Anyone having the experience of sampling the wretched stench of burning varnish would gladly drink bleach to wipe the odour from their memory banks. At our destination, the flaming alternator under the hood attacked our olfactory senses with that bouquet. Awesome, it must be a fire hydrant kind of day.
After disconnecting the smoldering wreckage and charging the battery (thanks 1st Class Auto Glass) we limped the Jeep with a new windshield home to find the man in brown had been by with a box from MSD containing an alternator. HOT DOG! Things were looking up. The MSD DynaForce alternator was originally slated to get strapped to the Merican Metal Menace engine build you have read about in previous issues of 4WD. With the Holley EFI system, three Maradyne electric cooling fans, DUI ignition, lights, radio equipment, winch and loads of other electrical gizmo’s to power, the upgrade was required, but we were hoping to hold off installing it for a while yet.
Many older Jeep and AMC vehicles use standard GM style alternators and mounting brackets. Stinky Jeep started life with a 37 Amp “10si” unit. It was then swapped for a more potent, but still junkyard fresh “CS144” unit capable of 93 Amps. The CS144 had been rebuilt in its past, but had an unknown history beyond that. In a blaze of glory, we killed that one too and swapped it for the now DOA 120 Amp that we scored from the boneyard as well. Although all these units are slightly different in size, their basic design and mounting bracket locations are very close to the same and are adjustable. The main difference being the connector wiring clip, which can be changed, but the MSD’s “One Wire” setup made changing ours a four wrench affair.
“One Wire” or “Self Exciting” alternators have a distinct advantage when it comes to a custom engine setup, or when trying to keep simplicity king in a trail rig. It really is as easy as it sounds; there are no external regulators, exciter wires or other superfluous connections. All you have to do is connect the positive battery lead to the alternator with the proper gauge cable, and forget about it. The unit determines when the alternator starts spinning at a high enough RPM to start charging the battery, and switches itself “on”. Other connections are present for more modern installations, as well as for other makes and models, but we chose to keep it simple, ‘cause we’re simple too. Just ask mom.
MSD’s DynaForce alternators are not a reconditioned or remanufactured unit like many others on the market. The have all fresh and made-in-North America components. This means that no worn or warped castings or other high mileage wear items will make their way into your hands. With the hot, high vibration environment they must live in, as well as the large loads it will likely see in the future, we took no chances and ordered up a 160 Amp unit with an old school V-groove pulley setup.
Please try to ignore the chrome cladding on our unit seen here. We went through the paperwork and realized we goofed and got this one instead of an “as cast” finish. It makes no difference to output capacity, but Stinky Jeep is no show rig and the chrome is just more lipstick on the pig. The handwritten tag hanging from the battery connection post was more important to us as each unit is tested after being assembled. Our unit belted out 110 Amps at idle and 170 Amps once it got moving. All this is with a peak voltage of 14.8 volts. The voltage aspect is important because some lesser units on the market are tested at a higher voltage to get big current numbers and applying too much voltage to charge a battery can cause it to boil. This is all bad for the charging system as a whole.
After installing the new ball-o-chrome under the hood in an hour, the rig fired up and went right to 14.5 volts… sans stink. The one wire setup allows for a less cluttered under hood area and makes troubleshooting an electrical system on the trail that much easier. It’s likely that we will never need to push the MSD unit to its 160 Amp capacity, but it’s nice to have the buffer. MSD has units for other applications as well as finishes, and output amps. For now, we’re moving from hydrant status to Augie Dog thanks to MSD.
MSD - www.msdignition.com