I replaced the headlight bulbs with a new set from langs the bulbs have one V shaped filament and one straight bar, the old bulbs were #1158s with two straight bar filaments, which I think are model A bulbs ? they both had the top of the bulb base marked, the replacements have no marking, after checking the current draw on both bright and dim Fil I couldn't see much difference Right now I have the V shaped filaments on the side facing the radiator and the straight bars on the outside facing the fenders since the V shape seemed to be just a little bit brighter, which way should they be installed both filaments are vertical when inserted in the stock model 26 touring headlight socket.
What answer did Lang's give you on their product and bulb installation ???
Don't really matter as the filaments should be horizontal not vertical. But, the off set filament would be on top. The majority of modern bulbs are wrong for the Model T head light socket/lens orientation and are sold to give you light not to drive at night with.
I have old stock 1158's in my '25. The DIM is only a parking light, 2cp. On is 20cp, which isn't too great. I think probably all they have now is made in China. Perhaps someday I'll order some of Langs bulbs that are 32-50cp, and use the 32 for around town, and the 50 for out in the country. As I recall, the generator can't keep up with the 50cp.
I recently picked up some "vintage" American Made 6 volt bulbs - headlamp, tail & stop and spot light - not too keen on the "imported" bulbs !
There were no instructions from lang's with the bulbs, no part number on the bulbs just 12v 50/32 CP. they have the filaments in the same direction as the two contacts on the bottom of the bulb, and same as the fluted vertical ridges on the 26 headlight lens, which when installed in the headlight socket on the 26 Touring makes the filaments both vertical. same as the contacts but the lock pins are horizontal, I wonder if the filaments are supposed to be vertical with the fluted lens ? I have a moped that uses a A3606 headlight bulb both filaments are V construction and are mounted horizontal, and there is a definite difference in light angle between high and low beam, while on the T, no difference in vertical angle but the light spread is less on low beam, But the lights are Bright and throw light a long distance out in the field, My observations, I have a call into Lang's to see what they say. Thanks Jim
Mark is correct as to how the filaments should be. The top filament would be low beam, and the bottom one high. It is possible to re-orient the socket by drilling a second hole 90 degrees from the original (I placed mine at the top to be able to focus easier) you can then remove and re-install the socket holder to align with the new focus screw hole.
Up Date. Snyder's has Model T light bulb's "Made specifically for the model T" so the filaments are horizontal when installed. 6 volt 50-32 CP $2.50 each. I Don't know if their 12 volt bulbs or Horizontal or not. but the 12 volt bulbs I just bought from lang's are vertical filaments when installed in a stock T, I can drill another hole in the light can to make them Horizontal,as was suggested.