The perfect conversion alternator!

70 amps, only needs an ignition and battery wire to run, has provisions for an indicator light and volt meter. Best of all, it has a vacuum pump mounted to run your wipers!

http://www.ebay.com/itm/NEW-ALTERNA...404-/120996580621?hash=item1c2bf54d0d&vxp=mtr

I'm going this route to convert my 56 CJ5 to 12v.

 

That's pretty cool with the vacuum pump!

I often think how to make the A1 more reliable for extended drives. The current stock mil fuel/vacuum pump has been rebuilt by Then and Now, but I find it hard to trust a complex device like that (the thing is a monstrosity). With a simpler fuel pump and this alternator, I'd reduce my chances of a breakdown stranding me somewhere. And I'd bet that vacuum pump is way more efficient than a pump with 1950 technology . Also, I may try to fuel inject that rig someday (future project) and the stock fuel pump would not work for that and if the fuel pump goes away, the vacuum pump would as well, since it's all one unit.

PO already converted to 12v.

Something to think about. Thanks for posting.

 

I feel quite differently. In my experience the military-spec stuff is 'bulletproof.' And Fifties technology was pretty well figured out. How much more "efficient" can a vacuum pump be?

On the other hand, I just bought a new alternator for my YJ. It actually came with a note from the manufacturer warning that attempting to charge a dead battery would destroy the alternator. WTF?

 

I've done it, and probably most of us have at one time or another, but charging up a stone dead battery by running the alternator is very bad practice. Puts a heck of a strain on the alternator.

 

A LOT more efficient. This pump lasts for hundreds of thousands of miles. It requires an oil line from the engine for lube to keep it alive forever, doesn't depend on a diaphragm that will eventually tear, and is a rotary vane that puts out full vacuum at idle.

 

Right. I've never had that problem with '50s technology. Or even '20s or 30s technology.

Just sayin'.

 

Interesting; I had no idea. I'm pretty sure the standard diaphragm pump achieves its full vacuum at idle also - the more pertinent question would be the flow rate or volume when in use and under demand.


Reminds me a bit of the "NASA space-pen" story.

Thousands of US dollars were spent to develop and produce a pen that would write in zero gravity, in a vacuum, upside down, below freezing, even underwater.
The Russians used a pencil.

 

This is what I had in mind.

The diaphragm vacuum pump takes a short personal hiatus every time you do any thing to drop engine manifold vacuum. It's always been one of the drawbacks to a vacuum wiper system. I live in the rainy NW and if I want to drive the rig outside summertime, it would be nice to have reliable use of the wipers.

The rebuild by Then and Now was around $150 for that stock military pump. Unnecessarily high unless you want to keep your rig original- my intent at the time. Most guys would simply be better off paying $100 for the alternator/vacuum pump combination.

Every time I jump in my jeep, I'm instantly surrounded by 1920s to 1950s tech and I own this jeep partially for this reason. But there's a good explanation for not seeing a lot of vehicles alongside the road like we used to see in the 70s- the technology works and makes for a more reliable rig. I won't change things too much on the A1 as long as it stays on the island, but if I ever venture into the big world out there with it, I'll either have to take along a bunch of spare parts or make a few changes beforehand. But that's just me

 

So, one thing that could be an issue with this alternator/pump combination is that it has an oil line to it for lubing the vacuum pump. I'm sure it could be plumbed into the F-head but these engines were never noted for high oil pressure at low RPMs. I wonder if that (and the passive filter system) is a potential problem.

 

The rotary vac pump creates enough vac to run a large truck's brake booster, all the time. The fuel pump vac can barely keep up the wipers when pulling a hill.

 

It should be fine, It just needs oil as lube, not anything under a lot of pressure. My 85 Isuzu Pup uses the same vac pump to run the booster. The oil returns to the crankcase through the pump discharge. You could pipe the return to the valve cover or the oil fill pipe. There won't be pressure if you aren't using any vac.

 

True enough as we all know and love. Condition of your wipers makes a big difference however. Most 50 year old vacuum motors are badly neglected and inefficient.

Never saw it on a Jeep, but some vehicles in that era had an accumulator tank to 'store' extra vacuum. (Although I'm not sure how you can actually accumulate something that isn't there!)

 

Old inefficient wipers are a problem, but I rehabbed mine to spec and they're still marginal. Vacuum wipers have their limitations- depending on manifold vacuum and the diaphragm pump are the big ones.