Correct Alternator for '68 Dart GTS

[charliec]

I'm going cross-eyed reading articles on the charging system for my car. '68 Dart, 340, w/PS, w/Factory AC. There are a lot of good articles on the board, but I don't have the time or patience to read all the back-and-forth about what alternator does what, and what the negative results might be if I use the wrong one. Ultimately, these discussions get around to arguing and explaining the design theory of alternators/wire size/etc., etc.

Background: I bought a PS car (without the pump), an AC car (without the compressor), and with an alternator that looked like it could have been strapped in place on the engine with a million flat washers, random odd-sized bolts and 3 rolls of duct tape. That's what I'm working with.

I've about gotten the PS pump worked out, but I'm still stumped with the alternator. The car had what appears to be the correct alternator brackets, but that's the last original part on that side of the car. The alternator was a square-back of unknown vintage or origin. I think the '68 models used round-back; I don't even know if round-back is still and option or if it's an option that I'd want to pursue. I don't give a flip about HOW an alternator works; I just want one that DOES work without having to patch and piece together a menajerie of washers/spacers other than what Mopar designed it to have.

I bought a rebuilt alternator from O'Reilly (sadly) that won't even fit the brackets. I am convinced from reviewing articles on FABO that the brackets I have or correct. The O'Reilly alternator is not. I bought a bolt set from Mancini that seems to be correct if I had the correct alternator.

Here are the photos of where I stand. I will post on the "parts wanted" thread for THE alternator for my application. In the meantime, if someone can offer some simple practical advice as to how to get this system up to reasonable standard, I'd be much appreciative.

 

[Dana67Dart]

Alt braket

Basic kit for a cast iron pre 70ish water pump small block.

Your 68 would have had a grounded field electro mechanical voltage regulator and would look like this

And be mounted to the drivers side of the master cyl on the firewall.

It has one wire that comes from the ignition and then I receive that runs to the Alternator Field terminal.

Your alternator would have been a grounded field (round back) type. Round back core are few and far between so rebuilders take an isolated field (Square back) type and ground one of the field terminals internally and it becomes a functionally equivalent substitute.

Lastly there are single pulley and double pulley alternators that will be dependent on your alt, water pump, ps pump, AC setup.

Look in your factory service manual for additional belt routing etc.

Post a photo of the alt you bought.

There are too many unknowns about what you have now to know what you need.

 

[4spdragtop]

Yes 68 would be round back. I believe squareback was 70 and up. That shouldn't make a difference to how they mount though. There's actually 2 or 3 different alternator adjustment arms.

 

[Dana67Dart]

There's actually 2 or 3 different alternator adjustment arms

And in there are the alt brackets for cast iron water pumps vs aluminum water pumps. And they do not interchange.

 

[halifaxhops]

Go into the IPB and see what your setup requires, Takes all the guess work out.

 

[Icetech]

for the voltage regulator, they make solid state ones that look like original mechanicals and they are cheap.. also much more even power, no flickering lights at idle or any of that.

My last mechanical one stuck on full charge which is not great..

1961-1969 Mopar, Chrysler Dodge Plymouth Voltage Regulator

Find many great new & used options and get the best deals for 61-69 Mopar Voltage Regulator, Chrysler Dodge Plymouth at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[HemiSSDart]

And it us a single field, the double fields did not come out until 1969, thought you can use one if you ground the second field to the body...

 

[Dana67Dart]

Go into the IPB

What's an IPB?

 

[charliec]

Hey, I found an NOS roundback 2098850 on eBay.........ONLY $2,200

NOS 1968 DODGE / CHRYSLER / PLYMOUTH ALTERNATOR 2098850 46AMP MOPAR 68 | eBay

 

[Inertia]

Maybe something like this

 

[Icetech]

I grabbed one off rock auto.. haven't had an issue

 

[halifaxhops]

What's an IPB?

Illustrated Parts Book, sorry. You can download them from Mymopar free. Will give you all the right part numbers you need.

 

[RustyRatRod]

You have the triangle bracket on flipped wrong. The "curve" goes to the bottom, not the top.

 

[charliec]

There you go!!! I'll give that a shot. Thanks.

 

[CRUZE 418]

FBO has an electronic stock looking regulator.

 

[charliec]

You have the triangle bracket on flipped wrong. The "curve" goes to the bottom, not the top.

I'll give that a look. But if I flip it to the bottom, it will be curving away from the engine, not toward it. Plus, the long mounting bolt won't line up to the threaded hole in the cylinder head, will it?

 

[Dana67Dart]

The brackets, bolts and spacers you have MIGHT be for aluminum water pump.
Post s photo of the alt you have now

 

[CRUZE 418]

With my luck, except my stock '72 318, I have had to make a spacer or two up to get the belt to align properly.

 

[charliec]

Somehow, someway...I think I stumbled across the proper fit-up.
Here is how the brackets attach. Note: cast iron water pump (as per '68). Three bolts mount to engine. The triangular bracket can only go one way for the bolt holes to line up.

Here is the set that Mancini sells. I think they must include pieces to accommodate more than one set up because I can't use some of what was in the package, and other pieces I ended up using differently than any of the photos I've seen in various posts.

I had to located the short spacer here (aft of the alternator mounting ear and fore of the bracket) in order to get the alternator cleared from the engine block and head. With that spacer in place, there is no room for the longer spacer. In most online photos I've seen, the long spacer is used between the two mounting ears of the alternator. However, the longer spacer is too short to fill the space between the two ears, and I can't figure out what purpose it would serve just to wrap aroung the mounting bolt anyway.

So, now I still need another short spacer to go between the aft mounting ear of the alternator and the cylinder head.

I accomplished that with a couple of spacers from Ace Hardware. There was only one short spacer in the Mancini kit.

With everything spaced as above, the tensioning bracket lines up perfectly.

Here is the spacing between alternator and engine block.

All that done, it looks like I'll get a pretty good lineup of the belt in the balancer and water pump grooves.

Now, I'll just have to take some measurements and try to find a belt the correct width and length. Thanks, everyone, for your help.

 

[4spdragtop]

No offense Charlie but that doesnt look right. The purpose of the long spacer is so you dont crank the long bolt down and collapse the alternator ears onto each other. Ill get pics of my setup ASAP.

 

[4spdragtop]

Now im not saying mine is 100% factory correct, but this is mine. Measure thickness of triangle plate, add the length of long spacer, that should = space between alt ears. The short spacer goes between alt ear and cyl head. Is there a spacer pressed into the rear alt ear?

 

[charliec]

I understand what you're saying about the spacer between the mounting ears to keep from crushing. That occurred to me also after my last post. I can use the longer spacer from the Mancini kit and cut it down to fit.

As for the short spacer I inserted between the fore alternator ear and the bracket, I believe that it has to be there in order for this alternator to fit; it moves the alternator foreward far enough for it to fit without contacting the engine. If you look at the photo I posted, there appears to be a "correct" gap between the engine and the back of the alternator body with the spacer the way I have it.

Yes, there is a short spacer pressed into the aft ear of the alternator. It protrudes slightly, but doesn't fill the gap between the alternator and the cylinder head.

All of this is subject to correction if I've got it all wrong. I'm just saying that after beating my head (and my knuckles) on this for a couple of days, it seems that I've come up with something that works. Is is as Mopar intended??? I can't say. In my research of this, I've seen several different setups and uses of spacers, washers, bolts, etc., all/any of which could be "correct" depending on how well they work for the user.

Thanks for responding. That's what makes this hobby fun.

 

[4spdragtop]

I agree, use what you can, where you can. My alt is the same with a spacer pressed into rear ear. That spacer can be moved in/out to take up or remove slack(somewhat).
I also bolted the end of the slotted alt arm to the "middle" threaded bolt hole in triangle. My reasoning for that was I didn't want to loosen/tighten the bolt that goes thru timing cover into block possibly causing coolant leaks if i ever needed to tighten.
There are several types of the slotted arms, some have a bend, some dont. Also your triangle has a bend as well, some do some don't. The infamous Ma Mopar puzzle lol. But looks like you are pretty much there!

I understand what you're saying about the spacer between the mounting ears to keep from crushing. That occurred to me also after my last post. I can use the longer spacer from the Mancini kit and cut it down to fit.

As for the short spacer I inserted between the fore alternator ear and the bracket, I believe that it has to be there in order for this alternator to fit; it moves the alternator foreward far enough for it to fit without contacting the engine. If you look at the photo I posted, there appears to be a "correct" gap between the engine and the back of the alternator body with the spacer the way I have it.

Yes, there is a short spacer pressed into the aft ear of the alternator. It protrudes slightly, but doesn't fill the gap between the alternator and the cylinder head.

All of this is subject to correction if I've got it all wrong. I'm just saying that after beating my head (and my knuckles) on this for a couple of days, it seems that I've come up with something that works. Is is as Mopar intended??? I can't say. In my research of this, I've seen several different setups and uses of spacers, washers, bolts, etc., all/any of which could be "correct" depending on how well they work for the user.

Thanks for responding. That's what makes this hobby fun.

 

[Dana67Dart]

Plain and simple .... You have the wrong alternator brackets for a cast iron water pump.

This kit is for 70 and later Aluminum water pump
MRE - Alternator Mounting Kit

This is the kit you need
MRE - Alternator Mounting Kit



Note the triangular bracket is flat.

The spacers are numbered as in the photo i posted in post #2

The adjuster bar goes into the lower of the 3 bolts that hold the bracket to the water pump. Like you show in post #1

Something to note.....

Some of those bolts if too long can crack the front cylinder wall, and use Thread Sealer on them, at least 2 go into the water passage

 

[charliec]

Plain and simple .... You have the wrong alternator brackets for a cast iron water pump.

This kit is for 70 and later Aluminum water pump
MRE - Alternator Mounting Kit

This is the kit you need
MRE - Alternator Mounting Kit



Note the triangular bracket is flat.

The spacers are numbered as in the photo i posted in post #2


View attachment 1716481742


The adjuster bar goes into the lower of the 3 bolts that hold the bracket to the water pump. Like you show in post #1

View attachment 1716481754

Something to note.....

Some of those bolts if too long can crack the front cylinder wall, and use Thread Sealer on them, at least 2 go into the water passage

The brackets that you say i need are the ones I have. They are correct for a '68 Dart with a cast iron pump according to everything I've found in articles on FABO. The plate piece has 2 holes to mount through the water pump into the block and one hole to mount to a threaded boss on the water pump. This bracket piece has a curve in it that curves toward the engine when its mounted. There is a short spacer that goes between the bracket and the water pump boss with that short bolt. The only other hole in that plate is where the alternator mounting bolt goes through and into the chlinder head. The adjuster arm bolts on top of the plate bracket, and it has a crook in it to space it around to the front of the alternator where the adjustment bolt goes in.

Given all that, I don't know why you say I have the wrong brackets.