Last week my son and I participated in the 2013 Michigan Jamboree in Petoskey Michigan. We did some night driving and found that the 1926 headlights are something to be desired. The last night driving we did the passenger side lamp wires fell out and this made me want to try and get the most out these lamps. At home, I started to read as many posts as I could regarding brighter headlights. I suppose that I could use better (halogen) lamps, but not wanting to spend more money, I thought I’d try some of the other suggestions. First I found that the bucket ground was rather poor. I ran a wire from the negative terminal of the battery directly to the lamp socket and found that the light became brighter. I measured about 1.5 amperes in my temporary jumper. So, I added a wire from the socket to the bucket as shown in an earlier post. This change made a noticeable improvement.
Then I wanted to know about the bulb. I have a standard bulb that has a triangle filament and a straight filament. The triangle filament draws 3.2 amperes on the bench (no wiring or switches) and the straight filament draws about 4.2 amperes. So I figure that the triangle filament is the DIM setting and the straight is the HIGH or ON. I found that I had the wiring on the car crossed, using the above assumption. I then wanted to check the focus of the lamps. I read that the triangle filament was the one that would work with the parabola shape of the reflector. I set up a wall with a ruler on it in front of the car. I operated only one headlight with the lens removed. I shined the light on this wall and took the following pictures. With the focus adjust placing the bulb the farthest away from the reflector I took the first picture. Then I took three more pictures as equidistance adjustments and one at the inner most adjustment. The triangle filament started as a 16” diameter circle,
the first adjustment reduced the size of the circle to about 14”.
The smallest circle, 12” was the middle adjustment,
as the bulb was moved closer to the reflector the circle increased in size, 14”
and then 16”.
These measurements are estimates, but you can see the circle size change. The same settings were also done with the straight filament. Here I didn’t have a circle, it appeared that there were two circles on a slight angle with vertical. As the same adjustments were done the upper circle became dimmer as the lower circle became brighter. At the middle adjustment, where the triangle filament had the smallest circle, both circles were about the same brightness. At the inner most adjustment the lower circle was bright and the upper circle dim. To my eye, I could not really tell if the HIGH was brighter than DIM. Anyway I’ll adjust the bulb to the smallest circle on the DIM setting.
I suppose the next item will be to attempt to align the headlights.
If you have clean metal ground contacts, the bulbs will be their brightest.
Clean & brighten the bucket where the new socket slides, do the same to the bucket attachment at the cross bar and the fender attachment.
The Green book shows the approved method of headlight alignment and focus.
Kinda found this interesting. My car has vertical flutes headlight lens and when they are on the circular pattern of the headlight beam is converted into a rectangluar shape.
There won't be a noticeable difference in brightness between bright and dim for the stock bulbs if they are both 32CP. The difference is filament location in relation to the reflector's focal point.
I think I have 32/50 cp. Don't reaLLy know, they came with the car. I figure that because of the current 3.2 and 4.2 amperes.