1923 23 Series 4 Cyl - Radiator Cap Question

[Guest 1923 Buick 23 Series Sedan]

I have a 1923 Buick 23 Series 4 cylinder sedan with a stock radiator.  I have a Motometer but I do not have a radiator cap for the Motometer. I measured the diameter of the radiator neck - 2.1" OD.  I have checked with traditional parts places for a replacement but everything they can get me is 2" OD.

 

Any suggestions on a cap replacement?  I  can find nothing on ebay.

 

Thank you.

 

Travis

[JFranklin]

Keep your eye on Ebay or such for a 23 Seris 4 Buick cap. You can drill a plain cap or your old one maybe.

 

[Leif Holmberg]

At the first,how do your model 23 series Buick looks like,what I know all 1923 4 cyl.models are serie 30.(exept from the trucks?)

Are you really sure you are messuring on the right way,you can`t meassure the outer dimmention on the radiator neck and the inner diameter on the radiator cap,that will be some differens?

Leif in Sweden

[Hubert_25-25]

Travis,

    Buick made a couple different sized radiator necks. and the fill nozzle for your car is some goofy "Buick sized" just over 2 inch (2.080 OD) and 16 threads per inch.  Your motometers are on Ebay, but no sellers know what they come off of.  Others have mounted them to a piece of wood or plastic and they will not check the thread size.  Here is my work around and how I have bought several correct caps.  You have to make it easier for the seller to give you the right answer.  Copy this and paste this text into the area on Ebay where you can "contact the seller".  Include these 3 photos too. 

 

They made a couple sizes of these motometer caps for Buicks.  I would like to put this back into service on my car and not on a shelf.  Ideally I would like to know the Inside diameter of the threads, and you usually need a micrometer due to the thermometer bulb sticking out in the middle.  The threads per inch are useful as well, but for this you would need a thread gauge.  Can you at least wrap a string around as shown, or better yet a tape measure and provide an outside diameter of the threaded area.   Thank you,  

So

- I look for an outside circumference of the cap in the threaded area.  (converting diameter to circumference)

      a - If the outside circumference is 7 1/4 to 7 1/2 from the seller, it is the 2.080 fill nozzle Buick cap.  (Earlier and smaller Buicks - up to 1925 Standard)

       b - If the outside circumference is 8 1/4 to 8 1/2 from the seller, it is the 2 3/8 radiator cap. (1924 6 cyl, 1925 Master, All 1926-1928)

- I only buy motometer cap combinations with Buick in the motometer.  No telling what I will get otherwise, and I can always resell, but I have not had a mistake yet.  All the parts can be purchased to fix a bad motometer. 

 

Hugh

Edited March 17, 2017 by Hubert_25-25 (see edit history)

[Thriller]

I have a 1923 4 cylinder with motometer and could verify measurements etc., but I don't know how soon I will be able to get out to where it is located. 

 

[West Peterson]

I have a cap that measures 8 7/16s od just like the one pictured above.

[Harlie123]

On 1/29/2017 at 12:31 PM, 1923 Buick 23 Series Sedan said:

I have a 1923 Buick 23 Series 4 cylinder sedan with a stock radiator.  I have a Motometer but I do not have a radiator cap for the Motometer. I measured the diameter of the radiator neck - 2.1" OD.  I have checked with traditional parts places for a replacement but everything they can get me is 2" OD.

 

Any suggestions on a cap replacement?  I  can find nothing on ebay.

 

Thank you.

 

Travis

Hi I have a 1923 original radiator cap, my uncles father had a luxury car company back in the day and after the death of my uncles last year we found it in the garage with numerous car parts