Splitdorf porcelain spark plugs

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2015: Splitdorf porcelain spark plugs
Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Blancard, Fredericksburg Va on Thursday, March 05, 2015 - 04:42 pm:

I have some splitdorf white porcelain spark plugs, some are marked "1" and others "775". They look nearly identical. I've seen references to the "1" plug being for a model T. But I've found nothing definitive about the 775s. Has anyone run the 775s or tell me more about them? Here are two of each.

plugs


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Thursday, March 05, 2015 - 04:56 pm:

Maybe contact these folks?

http://www.spcoa.net/

If they send you something really cool, like a Splitdorf heat range chart or a Model T spark plug cross reference chart, please post it here, thanks!

:-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Fielding on Thursday, March 05, 2015 - 05:13 pm:

Steve,
775 refers to the quality of porcelain that was used. My guess number 1 is the plug number.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Blancard, Fredericksburg Va on Thursday, March 05, 2015 - 07:18 pm:

If 775 is the type of porcelain of the one so marked, is the plug marked "1" a different porcelain? Are they essentially the same plug? Has anyone run either of them?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Blancard, Fredericksburg Va on Thursday, March 05, 2015 - 08:28 pm:

I found this catalog listing for Splitdorf porcelain plugs. It lists the #1 for the model T. But no mention of the 775 type porcelain.

plug1
plugAe


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Thursday, March 05, 2015 - 09:15 pm:

Paydirt, way to go Steve! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Thursday, March 05, 2015 - 09:26 pm:

Steve's document says that the Splitdorf plugs have a "Semi-Petticoat" design, what is that?

The table says that an AC1075 plug is equivalent to a Splitdorf #1.

Now, if we could find a similar table for other plugs, life would be good! :-O

Is anyone running either Splitdorf #1s or AC1075s in their cars? How do they compare with Champion X's?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Fielding on Thursday, March 05, 2015 - 09:28 pm:

Steve,
here is a short history of 775 porcelain

www.spcoa.net/quick-history-of-the-spark-plug/


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Blancard, Fredericksburg Va on Thursday, March 05, 2015 - 09:34 pm:

Thanks Kevin, very interesting reading.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Blancard, Fredericksburg Va on Thursday, March 05, 2015 - 09:51 pm:

The above catalog pages are from 1930. I just found this ad from 1926 showing a 775 Splitdorf plug. Perhaps they used 775 when these porcelain plugs first came out to capitalize on the new material, but dropped it by 1930 in favor of marking for specific applications.

nuther plug


Top of pagePrevious messageNext messageBottom of page Link to this message  By Verne Shirk on Thursday, March 05, 2015 - 10:49 pm:

A spark plug collector friend of mine said there was a porcelain manufacturer back east in the early days. Probably the Frenchtown Porcelain Co. mentioned in the link above. He said you could get any porcelain you wanted from them. You could apparently even get one with your name on it. The porcelains from that company were all marked "775". Here's some more "775" plugs. I know I've seen lots of other "makes" with the "775" on them. The one on the left is a B & B Air Cooled, Pat. Sept 1928; the middle is a Porter #3 KeepKleen with pat. dates of 1914 & 1917; and the Splitdorf with the "775" on it. I've been trying to collect up sets of the Splitdorf's for my early T's


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Blancard, Fredericksburg Va on Friday, March 06, 2015 - 06:47 am:

Thanks Verne, that 775 porcelain must have been something very special.  I found an ad for 775 Splitdorfs for the model T.  So I'd say the 775 and 1 plugs are about the same.

775ad


Posting is currently disabled in this topic. Contact your discussion moderator for more information.
Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration