Can anyone tell me what this fitting is ? It is on the left front lower engine{see pics}
It's for an accessory external oil line that brings oil from the mag post to the front of the engine. Lots of folks install them to keep the front lubricated when going uphill.
By the way, I see you're new to the forum. Welcome. If you're also new to Model T's, you need this:
http://dauntlessgeezer.com/DG80.html.
Thanks for the response. I have a 1923.
Walter, I also have a 23 and have that fitting on the engine. It's got a hollow bolt and an outside oil line from usually the hogshead magneto pick up goes to it. When climbing a hill, more oil is in the transmission and is kicked up to the mag post where it is directed to the front of the engine. Some work well enough to supply a cup of oil a minute to the front bearing. As the T has no pressurized oil system, the front bearing sometimes gets dry especially on a long uphill pull and burns out the babbit. This tends to prevent that from happening.
If you want to re-install an external oil line, the vendors sell a kit, this is an example from Lang's, but the other vendors carry them as well:
http://www.modeltford.com/item/3082OL.aspx
The line has to pass through some tight quarters at the front of the engine, be careful to route the line so that it doesn't chafe against anything. Be sure to have someone move the spark advance through its full range while you watch to make sure that the spark advance linkage doesn't rub and eventually saw its way through the line.
Walter, installed one on my 25 a few weeks ago, here's a short vid of what it looks like installed.
https://www.youtube.com/watch?v=GiFkkQtsxVU&list=UU-iWqNXjszxjQ3W01xWvDiQ