bobb

Hi Guys,

What was the deal with open faced alternators in 442s and W30s in 70-72?

I was under the impression that 70 W30s and 442s had open faced alternators, but what if the car had air conditioning or power accessories that required a higher output alternator? Did the car then get a closed faced alternator with the voltage regulator on the firewall? I've seen claimed W30s both ways and I'm confused.

I also don't know what happened in 1971.

I do know that my 72W has a closed faced alternator with the regulator on the firewall and no AC or power options.....so I assume there were no open faced alternators in 72.

If someone could clear up what came with an open faced alternator and what didn't I sure appreciate it.

thanks,
bob

stevengerard

what I have researched (which does not mean it is correct) is that in 1969 GM put internally regulated alternators on the Corvette and in 1970 they put it on the vettes and the 442s (all open-face). In 71 they went back to externally regulated alternators and in 72 they started to phase the internal ones back in. By 1973 all the alternators were back to internal. So 72s came both ways IRC.

There was a high output 1970 open-face alternator #11100890, 63 amps, my car has one and it came with lots of options including A/C. The reason they are so expensive/rare is that the vette guys have made the most in getting them for their restorations. As far as I know 70 was the only year for an internally regulated open-face alternator on a 442, but there are earlier dated alternators I have seen that are open-face.

bobb

Hi Steven,

Thanks for the info. Let me be a little more pointed with another question. If I run across a 1970 claiming to be a 442 or a W30 that doesn't have an open face alternator, or does have a voltage regulator on the firewall from the factory.......is the car a fake? What I'm asking is having an open face alternator on a 70 positive proof the car is either a 442 or a W30?

I ask because my Olds buddies at work are constantly picking my brain about how to tell if a 70 W30 is real or not if there is no documentation. I realize there is no 100% positive way to authenticate without documentation, but I've been looking for the open face alternator, no voltage regulator holes in the firewall, the rear axle code, etc, as good indicators, but not positive proof.

Then last week there was a claimed original paint Aspen Green 70 W30 on eBay in South Dakota........it looked pretty legit from the few pics, but it had a closed face alternator and a voltage regulator on the firewall. It was an AC car so I was wondering if ordering AC would negate the open face alternator.

thanks,
bob

stevengerard

The good thing about 1970 is you can easily prove its a 442 the VIN needs to start with 344, if it does it is a 442. from 68-71 442s were their own model. The only year the VIN tells you its a W30 is in 72 as the fifth digit signifies what engine the car came with. X denotes W30, but in 72 you could have a 442 with a 350, the 442 was an appearance option that year.

All 1970 442s came with an open-face alternator from what I know but it doesn't mean that somewhere down the line (even the first year after being purchased) someone didn't change it to an external alternator. The open-face was not specific to W30 or not W30, it was on all 442s. Seldom do I see openface alternators on even the best and most expensive restorations, it seems only those cars still with them or fanatics who know better make sure the car has it. I was just dumb lucky enough to keep mine when it failed (along with the master brake cylinder and a few other parts)

There is no way to really prove a W30 for 1970 or most other years as noted. The OW automatic trans is a great place to start as even though that could be considered a bolt on that's hardly an easy thing to find and replace, much easier to slap on a set of heads. The best thing to do is check all the numbers, Heads, Carb, Distributor, Trans, axle, red inner fender wells etc. W30s came with the sport mirrors and the W25 OAI hood. Most people think they came with sport wheel and ralley gauges but those were options even on a W30. I've seen a few W30s with bench seats (mostly convertibles so that doesn't prove anything either, buckets were standard on 442s but a sport split bench was an option on the convertible) Hope this helps

tru-blue 442

I don't know if this helps or hurts,
but my 69 442 has an open face
with built in regulator from the factory.
I think they all did in 69, on the 442's.

Rocketbrian

My non-W30 71 442 has an open faced alternator , just a 37 amp as it doesn't have A/C or defroster. The internal regulators were in 70 and 71 as far as I know. Interesting about the Corvette people. Was the open-face for cooling?

stevengerard

maybe 69 did as well then. I've seen 69 dated open-face alternators I have a list somewhere of what years they were available. I wonder if it was all 69s or a midyear thing. How about 68s?

Wow and an openface made in august 1970 - that would definitely be for a 71. SO see what I read was probably a generalization or maybe 71 was internal and external and 72 went back to external and 73 was all internal again. Hmmm

And yes I was told the open-face was for cooling purposes. But as you see we now have a 69, 70 and 71 open-face alternator and I thought 70 was the only year on the 442s

stevengerard

ah ha, found an image from Brian Trick I believe, this shows the back of a 69 vs 70/71 openface alternator for a 442

bobb

Hi guys,

I hear what everyone is saying about how common it was to replace an open face with a closed face .......but was it really that easy?

If were talking early 70's timeframe you'd first you'd have to get an externally regulated alternator and an external regulator......both of which I'd assume were easy to do. But then you'd have to find/make/buy/steal the wiring harness that goes to the external regulator and alternator, as those wires and the connector to the regulator are not in the engine bay harnesses for an internally regulated (ie, open faced) alternator. That sure seems like a lot of work instead of just getting another open face alternator.

Now if we're talking later........when the newer one wire internally regulated closed face alternators became the norm I could see how easy it would be. Were the open faced alternators that much more expensive than their externally regulated brethren back in the day? Just thinking.

later,
bob

tomsw31

As Steven has discovered the 1969 and 1970 442 alternator is more unique than just the open face. The diamond backs are very rare and unique to Olds, Corvette, and Pontiac in 1969 and 1970. They reproduce the open face fronts and they are readily available. I have seen national show winning cars missing the diamond back and it is a detail that is often missed or not not known about.

70Post

?? - who? Corvette repro place?

bobb

Patton,

Check out the link. This auction is closed, but he's always listing them on eBay.

bob

http://www.ebay.com/itm/1968-69-70-O...item2318518159

costpenn

I remember when I was running auto parts stores years ago ocasionally seeing one of those oddball rebuilt GM internally regulated 7127 style alternators - with the front casing looking like it had been broken or was a made from a cheap casting allowing all the guts to be exposed - if I only knew then what I was looking at.

Rocketbrian

What is meant by diamond back?

stellar

look at the pics in post #8

Rocketbrian

I see the back of my open faced alternator is different than those two. Mine was built in Aug 70 for the 71 model year. Are there three different backs, a different one for each year?

pcard

Here is some info given to me by feloow CO member STELLAR (Mark). He has been rebuilding alternators and starters for 35 years and has probably seen it all. I quote:
"
I do have some knowledge, but limited. The open faced design was the first venture into the internal regulator for Delco. I think all of the early internal regulated alts were of the open face style. I had an alt with the open face design for a corvette 1100859 that was made in July of 1968 or maybe that was the olds,. This was for 69 model year. I also had a pretty early one for olds 1100853 is the number if I recall right. My past posts may show it . The pic of the rear end frames with the diamond are correct in the post you guided me to. Cadillac Pontiac and Buick also used the open faced. I have one of the Cad and Buick from 70-71 era and they use a different rear case. It is like the ones used from 73 on. I think the last open faces were mid 1971. As far as the better cooling aspect goes, it may be true, but I would think it was just part and parcel with the new design. I know the diamond with the fins was for cooling the regulator better. More than likely using less aluminum was the original goal. Since the ends were very fragile and broke easily I suspect Delco redesigned them for the 72 and on models. At that time the mechanics at the dealerships were taught to repair the alts at the dealership. The open end frame would easily break when attempting to press out the rotor for rotor or bearing replacement.Delco also rebuilt alternators and I would think it would be cost effective to use the later end which was stronger. Most models of GM were pretty straight forward as far as the alt and starter application numbers. Olds seemed to not be the same way especially when you throw Hurst into the equation. We used to joke years ago that Olds was GM's testing playground. I am pretty sure GM would put out some experimental cars using different parts at times. I have had dealers bring me OE parts to rebuild that they were unable to get or even have a listing on and they were factory installed. Little did they know a common replacement part would work, but they were afraid to use anything but what came from the factory. Of course I didn't tell them they could use a part they had on their shelf and I would rebuild the oddball unit they brought me. These are just my opinions and not known to be fact, but this is what I think. So this whole story may be useless. Mark"

stevengerard

again only what I heard, but more than one person older than me has told me Oldsmobile was used as the test mule for what eventually went on to a Cadillac especially in the 50s and 60s, would love to hear from the folks on here who were there at the time

stellar

Yes 3 different backs, but not for each year. 69 was a beast of its own. The threaded mounting hole on the back was flush with end plate and in a diferent position. See diamond back pics. 70 and 71 diamond backs had the threaded mounting hole in a different place and it had a raised boss about 3/8 of an inch extending from the end plate. Another end plate was used that looks like yours in 71 and 72 with no diamond. So your back may be correct. You see oddly enough they also used the same end in 71 and 72 with an external regulator alternator. In 73 it changed slightly having a NUB where the plug goes in to the alternator. If you have a NUB it is a 73 or later end. You must realize these were transition years where they made an external regulator alt and an internal regulator alt for the same years. So for a 71 it could have had a diamond or a back like yours. 1972 all had backs with no diamond. 1st pic is a 1971 with an internal regulator and no diamond. 2nd pic is a 1971 with an external regulator and no diamond. 3rd pic is a 1973 and has the NUB. The NUB is located just below the prongs that the plug goes into. It is a little round piece sticking up from the bottom of the case right between the prongs. The holes and complete end are identical except for that. You see with the NUB the external regulated plug can't be accomadated. It won't fit. Without the NUb the end can take both the internal and external plugs. Remember they were using both in 71 and 72. 1973 all were internal and the NUB was used to help support the plug for the internal style. 73 on have the nub. You could always grind the nub off to look OE, but it does help support the plug. Often there is a date stamped on the inside of the case too. you may look in there to see what year yours is.

stellar

I am pretty sure you are right about 72's not having the open face.
I am also pretty sure all the open faced alts had an internal regulator.
I am also pretty sure you will not get all your questions answered satisfactorily. I sure hope someone who is sure chimes in, but even then I wouldn't be so sure. I sure hope this helps, but I'm pretty sure it won't.

70Post

Those guys.....I've heard of them before. Apparently have A LOT of alternaors and on ebay all the time. A buddy of mine got an externally regulated alternator from them. Decent prices from those guys.

Thanks Bob!


Also - I THINK Olds only used the 6 spoke open face alternator....more common are 5 spoke open face front halves. Used on certain Pontiacs and Buicks in the early '70's.


EDIT/ADD: Correction - I believe '71 442 alts were of the 5 spoke open face front half.

charlierogers

good info here!