question about old spark plug

[boojagirl]

I found an old spark plug in the backyard where I found that other stuff, my batteries in my camera died so I can't take a photo of it right now, the thick bottom part is rusted but the thin, white, top part is ok and it says "leonard high compression, trade mark req, pat. January 26th 1932" on one side and it has the number 1 on the other side. Does anyone know when that kind of spark plug was used and what it was used for?

 

Amazon Forum Fav 👍

Minelab PRO-FIND 35 Waterproof Pinpointer Metal Detector for Experts with Tone ID & Adjustable Sensitivity - Grab it through Amazon!

[nhbenz]

I can't answer your question, but here's a link to one that has a photo, for what its worth. http://cgi.ebay.com/ANTIQUE-SPARK-P...ryZ74722QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[boojagirl]

Thanks for the link, I tried to look it up on ebay but I was'nt sure what to look under, the bottom part of mine looks like the one in the photo but the top part is different, I will try to find some batteries and take a photo of mine.

 

[boojagirl]

I found some batteries that had a little power left and took this photo, I could'nt get the glare off so you can't see all the words but you can see the shape of it, the 1 is on the back.

 

[dg39]

Looks like a model T or A vintage spark plug to me. 1920-1930's..

 

[Boobydoo]

I think these type of spark plugs are used in older tractors.

Here's a link showing this and other brands used in antique tractors. Hope this helps you naarow your search.


http://www.antiquetractors.com/Research/Spark_Plug_List.htm

BDoo

 

[Boobydoo]

lol... well, we'll see on that one.

I think these brands are also used in old Harley's too so maybe we need more info or pics to get the model number off of it.

Thanks for the nice comment anyway Angelo. You have smiled me!!

BDoo

 

[boojagirl]

I live in town so I am not sure how a tractor part would have gotten in my back yard, unless this used to be farm land before the town was built.

 

[numnydar]

I had plugs like that on a '38 Allis Chalmers Dozer I restored

 

[boojagirl]

I scraped off some of the rust off of the white part and found some more words and numbers, it says NOS 1,842.8334

 

[Boobydoo]

Thanks for the link, I tried to look it up on ebay but I was'nt sure what to look under, the bottom part of mine looks like the one in the photo but the top part is different, I will try to find some batteries and take a photo of mine.

The one in the eBay picture is missing the top screw on bit that the plug wire clips over, I believe, whereas yours has the top bit that screws on the exposed threads shown in the eBay photo. They are a match I think but the eBay seller states he doesn't know the make or model of engine it goes to... bummer.

BDoo

 

[Boobydoo]

I found some more info and now think this is a motor cycle plug, but still don't have conclusive proof.

Here's another older eBay action with a very similar but not exact Leonard plug and it says in the auction description...

"This is a pair of 2, new old stock, "Leonard" air cooled, rebuildable spark plugs, 14mm short reach, fits Vintage Indians. These are sold in the original packaging. This is a "period correct" replacement plug from the 40s."

Here's the link. If you're an eBay member you can view it.

http://cgi.ebay.com/ebaymotors/INDI...016QQitemZ260003464891QQrdZ1QQsspagenameZWDVW

good luck!
BDoo

 

[boojagirl]

Does it matter that the words on my spark plug are worded differently then the words on the spark plugs on the ebay photos? Is there a way to clean the rust off the bottom part or is it pretty much destroyed?

 

[Boobydoo]

Yours is different than the eBay one that I linked you to.
But I do think yours is an older, rebuildable style one very similar to that one in design and age. It's hard to say what it's from. We'll keep searching.

And, yes, there is maybe more lettering under the rusted area of yours but I would be careful about risking destroying your item just to find this info. Maybe someone will come up with some more info soon to get you closer to the exact use?

BDoo

 

[boojagirl]

here is a photo comparison of my spark plug and the ones in the ebay photos.

 

[boojagirl]

mine does look most like the 3rd photo except for the words, what do the letters POS stand for anyways?

 

[boojagirl]

ARGH!!!! I have been on here all day and I can't find any information about this spark plug! Sorry had to vent. Thank you for all your help Boobydoo

 

[jeff of pa]

mine does look most like the 3rd photo except for the words, what do the letters POS stand for anyways?

MABY "Positive"

 

[Boobydoo]

The number you referred to in reply #10, 1,842.8334 are the US Patent Numbers for this spark plug. There are 2 patents , 1,842,833 and 1,842,834.
Here's links to the USPTO that shows this patented spark plug issued to Calab E. Leonard. The title of the patent says "Aviation Plug", filed November 21, 1928. Patented January, 26, 1932.

http://patimg1.uspto.gov/.piw?docid...2,833.PN.%26OS=PN/1,842,833%26RS=PN/1,842,833

and

http://patimg1.uspto.gov/.piw?Docid...&SectionNum=&idkey=NONE&Input=View+first+page

So it appears that you have found an airplane plug Boojagirl.

Smiles!
BDoo

 

[boojagirl]

Thanks for the links, I did'nt know if Leonard was the first name or last name or what. That is interesting that it is an airplane spark plug, we have an airport in town but it is nowhere near my home, I will have to see if I can figure out how it got burried in my backyard, I should look some more and see if I can find anything else.