OK Fellows, someone out there has to know what the thread size is on a standard model T gas tank filler hole, say 1913-20. I know its a straight running thread and it's not 1 1/2" or 2" NPT (1 1/2 to small and 2" to big. I'm working on a custom project and need to screw a pipe nipple into the tank so I can put a fill hose on and route it out of a custom body. no guessing, either you know or you don't!
Yes I don't know. I measured 2 new brass caps. One measured 2.06 the other 2.10. Looks like 14 threads per inch but 16 also looks close as there are not enough threads to be sure. This rules of a pipe thread as they are not close to that diameter and they are both 11 1/2 TPI (threads per inch). It looks like a special and not a standard size.
Until someone comes up with better info (or if they slipped in while I was looking this up) that's the best I can do.
P. S. 2"-16 is a NEF Extra Fine Thread which would probably work but might be hard to find a tap and die for. Might be tight.
Correction. Might be loose.
i have a Two inch,#17 thread die. It is common plumber's thread
I see they are sold by Victor if you want to pony up the bucks.
The '2-1/8"-16 HSS Special Die, 4" OD' Looked to be the closest to what I measured. I didn't see the 2"-17's. Are the bungs they use in barrels close to this size?
Sorry Robert if we aren't giving you the answers you want.
55 Gal. drum bung is the first thing that hit me too. If you get no where here try one of them. If it fits there's plenty of adaptors that'll thread on. Don't know if it's actual pipe thread though.
Get a brass recessed gas cap from Lang's for $8.75 part number 2910BR and make it into an adaptor
OK fellows, 2" barrel bung is 2" NPT which I already knew, tooooooo Big. You would think everyone that makes the tanks would know what they buy, but what I'm finding is everyone subs the work out and don't know. I'm just going to buy another solder in bung and replace the one in the tank. Just for info the ODM of the cap is 2.093 and the threads measure 17 or 18 TPI. the only thing I've been able to come up with is possibly an old New York City fire hose thread, but the TPi is a little different. thanks for trying, Bob
What Fred said. I hate screwing with gas tanks. Flame & tanks don't mix well.
I wish you luck. For me, I use original gas tanks, and original gas caps, so I don't need to worry about that stuff!
Measure the outside diameter of the cap. Then using a vernier caliper measure the distance across several threads,crest to crest, then count the threads and divide by the distance. You now have the outside diameter and threads per inch. Chuck your part up in the lathe and machine the threads. Test fit in the tank.
Thanks Ted, I was hoping to just buy a premade pipe nipple, but nothing is ever that easy. I sold my lathe so I'll have to run it by the machine shop. Thanks, Bob
A machine shop can measure the threads over wires that fit in the thread v of your part and the gas cap. If these measurements are the same your new part should fit the tank.
I measured a cap I have and it is 2 1/8" x 16 TPI KBC tools has the die @$200 a pop.
Ted & Dave, thanks for taking the time to respond. I'm dropping it off at the machine shop later this week. I'm sure they will make me a short pipe nipple with the matching tread. Happy Holidays to all!