Jack Worstell

1937 Buick Headlight Bulbs

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We are thinking about converting our 1937 Special from 6V  to  12V   by adding  an alternator.

 

Question:     are there 12V versions ( regular filament) of the original 6V head  light bulbs ?    Are  there halogen 12V   versions of the original 6V headlight bulbs ?

 

Jack Worstell       jlwmaster@aol.com

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I don't recommend the conversion but if you really think you need an alternator, why not just install a 6 volt alternator. My 1937 Century was converted to a 6 volt alternator before I bought it. It works just fine. It would certainly be easier than swapping all of the bulbs in the dash and elsewhere.

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I just drove 10 miles through the darkness here in Hershey in a '41 Buick with 6-volt electricals and original bulbs and found them to be adequate for the car's modest performance. You might look into the halogen bulbs available through several vendors (there's a thread on it here somewhere) or maybe even converting to sealed beam. I converted my taillights to 6V LEDs and had good results, too.

 

The 12-volt conversion is almost always more trouble than it's worth and will probably diminish the value of the car. If you don't like the lights getting dim at idle, then an alternator might be a good idea, but a properly regulated generator should have no problem keeping up with your headlights. It'll discharge at stop lights, but it'll top itself up again once you start driving. Don't sweat that part.

 

A 12-volt conversion is not a solution to a problem you're having. It's an invitation for new problems you don't have yet.

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  Matt and Matthew, I can not agree with you on converting being more trouble than it is worth.  To each his own, but if it is not a show car I see no negative. I did mine in 2012 and am happy. I have had no problems. Probably 10,000 miles since. 

 

  I do agree that 6 volt will work well, if all is right.  The 6 volt alternators are great, I hear.

 

  B en

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5 hours ago, Matt Harwood said:

A 12-volt conversion is not a solution to a problem you're having. It's an invitation for new problems you don't have yet.

 

Well said.

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i am aware of the pro and cons of converting to 12V         and   I'm aware of the issues when making this conversion.

 

But still........are there 12V versions ( regular filament or halogen type )  of the original headlight bulbs for a 1937 Buick ?

 

Jack Worstell      jlwmaster@aol.com

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I am very much on board with the feeling that conversion is an extreemly bad idea.  However,  as that is not what you asked here is an answer to your actual question.  Yes there are 12 volt replacements available. The website I found says that the 12 volt replacement is bulb number 1026.  I do not know if this is actually accurate. I would be very suprised to find a halogen replacement available.  These bulbs are a very special design. They are not just light bulbs. They are specially designed to be prefocused to work properly in the origional headlight housings. I very much think that the desire for halogen replacements would be so small as to make building them impractical for a bulb manufacturer. I may be wrong, so your mileage may vary.   The LED versions may or may not work properly either. My 37 has had a sealed beam conversion before my father got it in the early 50's.  They work just fine also.

 

I just saw that there is another thread talking about halogen replacements being available, so my above thoughts are wrong. Not the first time....

Edited by 37_Roadmaster_C (see edit history)

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Thanks for the tips.

Yes I know that these bulbs are sort of special   ...they are   "pre-focused".....whatever that means ????   I guess it means that the bulb is meant for a specifically designed reflector....But then again aren't all reflectors parabolic so that any bulb of correct volts/watts/mounting base should work  ???

 

Jack

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Pre-focused means the filament is at a specific location, and the base locks into the socket at a specific location, so the optics of the reflectors and lenses will always be right on target of the photons of the filament. And this is for both high and low filaments. Imagine if you got the bulb upside down, the optics would be WAAAAYYYY off.

 

A typical bi-pin bayonet does not have this accuracy. 

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Yes, 12v bulbs exist. They exist in both standard incandescent and halogen. I believe LED also exist. Offhand, Restoration Supply  https://www.restorationstuff.com/  have the incandescent ones. #2326,  #2336, and #13007-12. I cant seem to find my bookmarks for the others. The same suppliers who have 6v also have 12v IIRC.

 

Edit: Here's the 12v halogens (6v too)  http://www.lbcarco.com/cgi-bin/gen5?runprog=lbcnews&page=/halogen.html

 

3 hours ago, Jack Worstell said:

Thanks for the tips.

Yes I know that these bulbs are sort of special   ...they are   "pre-focused".....whatever that means ????   I guess it means that the bulb is meant for a specifically designed reflector....But then again aren't all reflectors parabolic so that any bulb of correct volts/watts/mounting base should work  ???

 

Jack


Well... no

 

What "pre-focused" means is that the filaments are in a specific location with regard to the base. This means you can put a new bulb in without having to focus the light. Designs like this have a ring around the base to locate the bulb.

 

Yes, perfectly parabolic reflectors are common (not on the 37 Buick, but I'll get back to that).

 

Headlight designs generally have to have the reflectors and lenses designed around where the light is. "Where the light is" includes whether the filament is oriented side to side or front to back. The lit filament is sort of a cylinder shaped spot of light. To dip the beam in a parabolic reflector, you move the filament out of focus, or off of the center point.  How this is done varies.

 

Generally speaking there are 2 common types. One has the filaments running side to side, and has the low beam filament out of focus in the up/down direction. The other type has the filaments running front to back, and the low beam is out of focus in the front/back direction. The reflector and lens is then designed around where the light is.

 

The 37 Buick, and the old American sealed beam, are both examples of the first type. The European H4 is an example of the second. I sort of cringe when I see H4 sockets behind stock lenses in old American cars. Some people have reported good results with this, but the low beam filament is nowhere near where it was when the designer designed the lens and reflector. I would expect the result to be fairly random.

 

There were 2 types of these prefocused bulbs on American cars. There was the one that fits Buicks, Chevys, Fords, etc. (#2320, #2330, etc in 6v), and one for Mopars, Nashes, Hudsons, etc (#2321 in 6v). There isn't much difference, just enough that it wont work, maybe pin orientation or something.

 

There is also a standard for motorcycles that was used well into the 70s and maybe even more recently. This one is called "American Pre-Focus" or "APF". I believe this to be directly interchangeable with the Buick-Chevy-Ford bulbs. The only obvious difference is that these motorcycle bulbs have both filaments the same size (prewar car bulbs had a dimmer low beam sometimes, but not always), and are rated in watts rather than the candlepower used on cars.

 

This motorcycle stuff comes in both 6 volts and 12 volts in a wide range of wattages, the only restriction is that the low and high are always the same wattage. I believe many vendors are selling these for Buick-Chevy-Ford. All I have bought recently have been new production, and the quality varies wildly. (I have not bought any from the link above).

 

Halogen retrofit bulbs exist with the filaments in the right place but you have to look harder. I believe the car ones are the same as motorcycle.

 

The 37 Buick uses a system called "Guide Multibeam". The reflectors are not perfectly parabolic. If you take a close look, especially around the edge, you will see it is a contoured reflector. The bulb is also probably not quite centered. The lenses have a left and a right and are designed to work with these reflectors.

 

On more modern cars, with sealed beam headlights, or H4, or basically anything else, on low beam the light shines up one side of the road further than the other to maximize visibility while not blinding the oncoming drivers. A single headlight does this as well as two.

 

The Guide Multibeam is different. The lenses and reflectors are designed so that the one on the left side has a sharp cutoff up-down(!) on the left side, and the right headlight has a similar cutoff on the right side. The lights are aimed so they cross each other (yes, really). When you beam down for oncoming traffic, only the right headlight (which is shining into the left lane) beams down.

 

The headlight switch on the dash has 4 positions. 1) off  2) parking lights  3) city beam or low 4) country beam or high.

 

The dimmer switch engages "passing beam". This is not for passing as a modern driver might suspect, it is for meeting oncoming cars, and is high beam on the left lamp and low beam on the right.

 

 

 

 

 

 

 

Edited by Bloo (see edit history)
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Bloo....thanks for your comments.    Great information !      .....I understand all of this much better now

Boy....I never realized how involved lights/bulbs are....    a lot of angles to all of this

 

You have answered my basic question about 12V bulbs for a 1937 Buick.

 

Jack

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Incredible response Bloo. Thanks. 

 

Do do you know the year range your response covers? I'm wondering if it perhaps applies to the "rounded" lenses rather than the earlier flat lenses (like on my 1929). One lens was broken, and I purchased a replacement, but now wonder if it matters left versus right. I guess I may have to go digging into my documentation. 

 

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I don"t know how yours work.  There were several possible kinds of headlights back in that period.

 

I am fairly sure that 1929 is too old to have the "Guide Multibeam" setup.

Edited by Bloo (see edit history)
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Bloo....now that I better understand the importance of geometery/dimensions  with regard to light bulbs/reflectors...I have a couple of more questions

 

The original bulbs for a 1937 Buick were #2330         which uses two C2V filaments and the     lcl  ( light center line.....something new I have just learned ) is 1.13 inches

 

The 2326 and the 2336 use C2V/C2R filaments  The 13007-12 uses C6/C6 filaments.       So these substitutes have different shaped filaments vs the 2330.

Question   do these differences in filaments matter when choosing a substitute for the 2330  ??

Or.............since all four  of these bulbs have  lcl spec of 1.13 inches.........is this what matters and not the filament differences ???

 

Jack

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You just found out more than I knew. In old NOS/NORS 2320 and 2330 bulbs I have seen v-shaped filaments on both filaments, one filament, and both straight.

 

I have noticed in my 36 Pontiac (which also has Guide Multibeam), that the v-shaped filaments make the cutoffs sharper and the spot of light when aiming more defined. The service manual for the Pontiac specifies ONLY 2320L. BTW the 2320 (and 2320L) is just like a 2330 but with a lower candlepower low beam. The "L" is a long life bulb. They do not specify why only these bulbs. Maybe the long life bulbs have both filaments v-shaped?

 

I have always assumed that the lights were designed for filaments  either straight side-to-side or v-shaped, (but not straight front-to-back). Now, I am not sure.

 

As far as I know, if you want v-shaped filaments you just have to look at the bulbs (they will be NOS/NORS bulbs). 12v bulbs did exist for some big trucks.

 

There are no 2320 anywhere except NOS on Ebay onesy-twosy. 2330 is easier to find. I haven't looked for the 12v numbers.

 

I bought some 2330 from a well known vendor. They were in a bag from another well known vendor. They were obviously new production, and the quality was bad. They had straight filaments and one of them didn't even have the filaments in the bulb right. The filaments were sloping at about 45 degrees when mounted in the reflector. The pattern was really wonky, so bad it prevented me from aiming the light.

 

Another vendor online was reputedly the last source of 2320, so I ordered a pair. When I got them, they were new production 2330, not 2320. They were straight filament. They were obviously much higher quality than the 2330 from the other vendor. They worked fine.

 

All of these bulbs look like APF motorcycle bulbs to me. I suspect they are either relabeled, or the vendors are having them made by whoever is tooled up for APF.

 

The 13007-12 is, I think, a Ford part number, and probably why it is different style of number. I didn't know it specified a straight filament. I think you are going to get a straight filament no matter what you order.

 

2 hours ago, Jack Worstell said:

Or.............since all four  of these bulbs have  lcl spec of 1.13 inches.........is this what matters and not the filament differences ???

 

That is a very important measurement. It puts the high beam in focus. The low beam is offset a bit up. I have never seen the measurement for how far up. All of these bulbs seem to hold the same dimension though, except the sloppily manufactured ones.

 

For what its worth,  you can get the most improvement in light output by having your reflectors resilvered, either with real silver or UVIRA, and making sure the bulbs are getting full system voltage. These 2 things make more difference than anything else.

 

c2v%7Cc2r.gifc6%7Cc6.gifc2v%7Cc2v.gif

 

Edited by Bloo (see edit history)
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Thanks Bloo.         I think I know all there is to know now with regarding choosing bulbs for old cars.....and that there is some hit-or-miss in coming up with bulbs that will really work well.

 

..........I started off with what I thought was a very simple question.......!!!

 

Thanks again   Jack

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You can buy 12v head light bulbs that are identical to the the 6v bulbs.   I like the 12v system as there is the ole 'I squared R' issue.   The old wiring was sized to handle high current.   With 12v, you run 1/2 the current  with twice the voltage and thus carry the same wattage.  I needed to go to 12v because I live in Florida.  I have a 38 coupe  WITH air conditioning.    My car  is a driving car so its fun trying to tell people that A/C in cars did not begin until the mid fifties.   Yes there were some in the very top line cars but regular A/C was the mid-fifties as I  recall.  Yea, I'm old but having fun .    

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BTW, if you go to Halogen bulbs, they require more current to give you the bighter light.  So if you go 6v  with Halogen, your wiring needs to be very good.

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A second possibility is mounting "driving lights" like many of the old cars had.  Just use modern seal beams and hook them up with a second dash switch.  That way you can drive around with the old system and not 'blind' some one and when on the road crusing at night (?) you can have nice bright lights down the road.

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Jim...there have been several posts about the current draw of halogens.     After reading them and doing some research on my own.........my belief is that halogens can  give the same amount of light as incandescents and yet draw about  30-40 percent less power..    Of course there's no reason you can't replace a low wattage incandescent with a higher  wattage halogen   (so long as the wiring and power source will handle the change)   and then really get  much more light than otherwise.

So if halogens are substituted for incandescents of the same wattage....I think a person would get  noticeably more light.

 

....I like your idea of using add-on sealed beam lights as running lights....

 

Thanks everyone for the good info.....we'll have to sit down and decide halogen/reflector/alternator/12V   and see which compromise we think works for us .    And  I realize the downside of departing from originality.......we want a car that's fun and reliable to drive without making too many changes from "factory"

 

By the way....I clearly remember when PS and PB were novelties....so I don't think you're much ahead of me Jim.     Your AC   Buick...does it also have PS ?

 

Jack Worstell

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Nah,  i need to leave as much as i can.  I’m an old guy  (almost 75) and i remember regular steering.   Today you don’t have to parallel park.  My grand daughter just got her DL .  Nothing like that anymore.  Just training  for the simple stuff and train to look ahead and prepare.  I bought my ‘38-46s’  to have a “driving car” and not a show car.   Mine looks nice as a five footer.  Looks good and with over drive, i can go anywhere.  By keeping the original 4.44 rear i can do hills  and  65 mph and up.  (2350 rpm cruise).  Nice to drive.  I installed a 1953  263ci .   Gave me a bit more hp to run the ac.  Zero timed the tranny, shocks, outboard wheel bearings.  My friend wants to buy my ‘new’ ‘38’ when i sell it  :-))

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I wrote an article about 37 and 38 headlight bulbs and tail light bulbs in a TORQUE TUBE magazine a few issues back which gave all the bulb numbers I used. I kept the 6 volt system and had the headlight reflectors restored which is imperative if you really want good lighting. We drive at night a lot here in Las Vegas and the lights in our car work great. No wiring was changed and we still run the stock generator with no problems. 

 

OLD CARS AND TODAYS PROJECT
If anyone has driven the cars made in the late thirties or forties or fifties they remember when cars had six volt batteries. Everything must be like new for the headlights to work very good. The headlights back then were not sealed beam headlights, they had a bulb and a reflector and the bulb was only 6 volts. When the cars or motorcycles were new back then the reflectors were silver plated, silver reflects about 92 percent of the light that hits it. Even today that is one of the highest reflective surfaces there is. The problem is that when air hits silver it starts to tarnish and eventually it will turn black. In the old days you would remove the headlight ring held on by one screw and the glass lens to replace the bulb and at that time you would polish up the reflector once again giving you good light. This worked good for a few years but the the silver coating would start to go away with each polishing. Reflectors are conical in shape and thats why headlights make a BEAM. We have a 1938 Buick with terrible headlights, I replaced the bulbs with Halogen bulbs which are a little better but our reflectors silver coating was worn off in spots and thin in other spots. I found a place in Oregon that puts the reflective coatings on the parts of medical instruments used in laboratories such as microscopes. In order for them to do that the object they are coating first has to be polished and nickel plated. I sent my reflectors to a chrome shop where they were polished and nickel plated. I then mailed them to the UVIRA company in Oregon where they completed the reflective coating process.  We don't have any of these problems today as the headlights are sealed (sealed beam) and no air gets to them. In any case here are some pictures of some original reflectors and after they were nickel plated. We got them back from the UVIRA company and they looked beautiful. I installed them today and I took some pictures for anyone that might be interested in doing this to their car. Its not a hard job but it requires some patience to get the socket removed from the reflector. I also used Halogen 6 vole headlight bulbs with the same base as the stock ones. These are available from THE LITTLE BRITISH CAR COMPANY, their part number is
#170-756H it has a APF Base and its 6 volt 35/35 w. If your car is anything like mine was the instrument or dash lights do not light up the gauges very well. The same company also sells Halogen 6 volt dash lights, you will need two of them. Their number for the halogen dash lights is 170-155H. They also have Halogen Taillight bulbs that replace the stock 1154 bulbs. Their Halogen taillight bulb number is
 #170-706H.  All the Halogen bulbs draw LESS current than the stock bulbs. 

 

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Do you see any greater heat from the halogen dash bulbs than from incandescent bulbs?  I would hate to melt the dash gauge plastic material from excessive dash bulb heat.

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