My original thread with real pictures

I won't be making/adapting these anymore, so I wanted to share all the info I found.

I used the MechMan Alternators 150amp (Part Number: 7771150) but it's been discontinued. It's listed for a 1991 Ford F-150 5.0L motors. There are two different alternators with the same body (pictured below), the wrong one has the connector at 2:00 and the RIGHT one has the connector at 10:00. There are other options, but if I were doing another one, I would order the Bosch AL562X which is a 75A unit. There are aftermarket builders who make these up to 220A. Adaptation should be similar for all.

The image below should hit most of the major points, but here's a few extra details:

*If I were doing more of these, I would look into just making an alternate version of the upper and lower brackets to work with an unmodified Ford alternator. That way if you need one while away from home, it's possible.
*The unit I bought had an internal fan, the stock Ford units use a front mounted fan. If anyone tries this they'll have to confirm that the fan + pulley still line up with the fan pulley. Visually, it appears that the internal or external fan setup occupies the same space (compared to each other) but the internal just has extra material in the case to encapsulate the fan. So I suspect the fan will be a non-issue.
*These Ford alternators also use a ribbed belt, so a V-Groove belt would need to be sourced. I looked quickly on eBay and it appears that they should be pretty easy to come by.
*Offset drilling the upper hole is almost impossible to do freehand. You'd need to take it to a machine shop. I built a drill jig to keep my drill bit in the right place. The difficulty of this step is another reason why I'd recommend someone design new brackets -- you wouldn't need to drill this out and could simply loosen/tighten the upper bold 'from the back'. I'd be happy to loan out my drill jig. It worked for me and it should work on these, but I can't guarantee the location is perfect on all variations of this alternator.

And finally, when grinding/milling/cutting on the alternator body make sure to tape off any holes where bits of metal could enter the alternator.

If anyone wants to undertake this project, I'd encourage you to do it now. I may not notice questions or posts about this in the future.

Also, this would best be handled with the engine out of the car so you can see what you're doing (specifically ensuring the fan and pulley are inline).

So does the V-belt pulley fit right on or does one source a different pulley?

Thanks filling us in on your previous work. I do appreciate you restarting this Topic. I am going to dig deeper and see what might be out there with less mods. Might even take your advice and see what I can do about the bracket.

Here is what I found so far. Mechman has a 170amp model that looks a lot like the Bosch. This site has a nice dimensional drawing. I plan on comparing to my removed bosch this evening.... Fingers are crossed on that part.

One of Mechman's vendors has info too. https://ceautoelectricsupply.com/product/me...ent-alternator/

Before Mark mentioned the 91 ford model, I thought someone said something about a GM Alternator, so here I am with it. Mark mentioned the 10:00 connection and this one has that. the dimension of 143mm from the pulley groove to the back case is the smallest I found today.

Click to view attachment

Questions for anyone that knows more about ALT than me.... 1 wire vs. 3 wire. Differences...? Benefits...? Can either be installed on the 914...? where do the wires connect on the car..???

I did read that the 3 wire will NOT un-excite at idle. That is a benefit.

Here's the drawing of the 7771150. The one in the post above has the mounting holes closer together, and moving/drilling the top hole would get really close to the edge I think.

I guess I will keep this thread going until I make a decision about being able to upgrade. Our other member, Pete Newman is more than willing to make his HO ALT kits, but will require 10 buyers and I can't wait that long. Spring is coming and I want to DRIVE.

As time allows, I have been doing some research and I see WHY the ALT you suggest needs to have the holes modified. I found a video of an ALT being removed from a late model VW bus. I believe that is the ALT you suggested. It just did not make sense to me as to why a 79 bus ALT using a TIV engine would not be an exact fit. Now I see.

The top bracket for the ALT is different than ours. I wonder if I can find that bracket for use on the 914. The bus bracket is also anchored on the exhaust. Not that I will do that, but that is part of the difference. You can almost see the anchor bolt in this picture. It is kinda behind the red line at the btm. And you can see the bracket in question is rusty at the anchor point, no doubt from the heat of the exhaust.

Any BUS guys out there have a bracket I could buy? Know the part # or a good place to buy it?


Click to view attachment

Here is the whole video, if you are interested. It is pretty long. This screen shot is about 8 minutes in.

https://youtu.be/qwYcKWBbqjM

Well that did not take long. Here is a better view. Still no sellers found. EDIT: turns out this is not needed. The ALT i chose bolts up the the 914 OEM brackets.

Click to view attachment

An alternator with one wire has an internal voltage regulator while the 3 wire models require an external regulator. When rpms drop below some point the voltage regulator will stop the alternator from charging. Doesn't matter if it's one wire or three.

Not exactly. The Ford alternator has a built in regulator. You've got it confused with exciting. A one wire alternator will self-excite. A multi wire alternator needs external power input to excite (thus the extra wires).

Nevermind....

More to come.

McMark suggested a 75amp model and I found a 70amp alternator.

It was impossible to find a Bosch brand. But there is a brand called REMY. Part # 14062. They are all over and really not very expensive. Even found one vendor that will offer a 3 year warranty for $7.

As stated above they are used on the 75 to 79 bus type IV engines that had gasoline heaters and extra fans. Not an option that was installed on very many vehicles.

RATWELL.com has a nice write up about the differences in the 50amp and 70amp set up. There are a few parts and pieces that I am going to try to hunt down.

* REMY rebuilt 14062 delivered w/ 3yr warr. $114
* The cooling elbow is slightly different and I found several sources $15
* I need a pulley with a fan. Some Samba guys get frustrated in searching for the exact part and go without, so there is that. Found a BUG one and a CHEVY one for $15. Might need to modify, but hey, it's cheap.
* Might need a special top bracket. Found a Samba seller that wants $35 for the long bracket. Screw that. I think I can make one.
* Ratwell and others say that the Wire harness is different since the back plate is not there to protect the connector from HEAT. $92

Up to $271 total with the bracket
might need some additional BUS cooling tins I don't expect them to take me much over $300.

So I am going to buy all this and keep posting.

Front looks exactly like our 50amp model. The back has a built in cooling tube and similar if not the same electrical connection. What I would really like to see is a dimension drawing. Can't find one of those for our 50amp model either.

Click to view attachmentClick to view attachment

This is a great thread with a lot of great ideas! Keep it coming!

AFAIK, the Type4 bus alternator is a direct drop in. They were impossible to find new and pretty uncommon used, but if someone started remaking them that's the best solution. The bus upper bracket is just a longer version of our bracket. The alternator should still mount up to our bracket just fine.

I am dry fitting my 70 amp alt. I have a spare fan housing so that makes it easy to play with everything on the bench.

Click to view attachment

The silver alt cooling tin came off of my car. The black one came from Garold. Turns out my silver one had been cut by a PO. Garold's looks like factory. The main hole is smaller on his. And the flat plastic piece is also from my car. It also fits.

So the alternator is a direct fit, as McMark stated. I used both 914 mounting brackets too. I have not fit it all up with the black tin, but I will. As it goes now, a slight mod (making the hole bigger) is probably a good thing. Making belt adjustment easier, I guess.

Click to view attachment


More to come on the rest of the fit. still have to deal with the cooling elbow, the pulley and the front fan ( if I use it)

I can confirm that this unit is a direct fit, I installed one last year. No issues powering my HID headlamps and stereo

Let me ask you a couple questions then....

Did you use the cooling air elbow for the 914 or a VW bus?

Did you use the pulley with a fan on it.... also from the VW bus?

Did you have an issues with the belt lining up?

Clark can you post the source for the boot?

As far as the fan goes, I don't think you need one if you have the boot hooked up. With the boot air will be circulated out the front of the alternator by the impeller. The amount of additional cooling provided by a fan on the front is likely non existent.

Also I have found a few of the 7771150 Alternators out there.

Also if you want to look at some of the other options like the 10SI, or 12SI GM Alternators there is some good information here.

Not sure of any modifications required to make them work but I have found them as cheap as $60.

+1 ... I would like to know the above as well

I bought this one from aircooled.net $20
https://vwparts.aircooled.net/Alternator-Ai...022-903-655.htm

022 903 655 part number I got from this thread on the samba. I googled the part #
and got several vendors
https://www.thesamba.com/vw/forum/viewtopic...ight=alternator

VW made a few different ones. This one is for a BUS. The part that attaches to the fan housing is larger than the fan housing hole for the 914. Not sure if the bus fan housing is exactly like ours. But this elbow does not fit perfectly. The end that goes on the built in tube of the alternator fits perfectly. I don't know if the 914 elbow will fit the built in alt tube. I am going to have to remove my elbow and check.

Samba photo shows the differences. Funny thing is my car is a 75 and the fan housing I have on my bench is a 71. So I may be dealing with 2 different animals.

Click to view attachment

FAN: That is what the Samba guys have been doing, just leaving the fan off. You have to wonder why the VW engineers included it in the '79 70amp alt. I assume they were expecting extra heat from all the camping accessories and heater fans.... which the 914 does not have.

I think I mentioned that I found some fans that slide on the shaft with the existing key. Your link shows a photo of just that. Maybe GM models for about $15, so it might be simple to attempt to install and get a bit more cooling.

The 7771150 is the Mechman one that I really wanted to try. McMark used it. With 7" hole-to-hole dimension, it should bolt right into the 914's brackets. And IIRC the Over all diameter is smaller than our Bosch Alt. But it is now discontinued. I found a few are remaining out there. But they are $250-ish.

I ended up putting this project on hold.

The Alternator arrived damaged by UPS. I rotate the shaft and there is a sticking place 1/2 way around. Huge hole in the inner and outer boxes where the shaft poked thru in transit.

I called CarID and they said keep it, we will send you a new one. 2 days later they say they are on back order and it will be at least 30 days. I checked around and several other vendors are out of stock. This might be the end of the Remy 70 VW alternator.

So I installed my spare 50amp cause I want to drive. So 50 amp mounted, new belt adjusted, tins and exhaust re-installed, test drive complete. 13.3 volts at idle with the lights, hazards, radio, wipers on. 13.9 at 3000 rpms.

Going for a Sunday drive. I will pick this back up in April, I guess.

I think Mark said in his initial post, but I’m not sure.
Can I take my stock alternator to a rebuilder and have them make it higher amp in the same body? With a built in VR?

You can have it rewound to higher amperage, but there's a limit and you need to find an alternator shop that can rewind the armature (amps are increased by changing the number of turns, and more turns take thinner wire to fit in the same space). But you can't have an internal VR added.

wondering about the cooling boot - I got a new one from a vendor, correct part number but the part that goes into my fan housing it loose, the fan housing hole is too big - which boot did you end up getting that fit correctly?

My car is a 75. The test fit fan i am using might be a 71. I bought the boot that samba or ratwell said would fit. Turns out the housing hole might be smaller on my test housing cause that boot squeezed in but did not seat. I could not get the spring in.

I did not want to remove and measure the boot from my car. I was afraid it would be hell to get back in with the spring and all.