Gas cap with gauge
Posted: Fri Dec 30, 2022 6:28 am
I dont like not knowing at a glance how much fuel I have.
The black gas caps with the built-in guage are ok, but a real fuel guage is what I really want.
So I've ordered one from AliExpress, for about $22, both sender and gauge itself, and I'll install it... this spring some time.
Meanwhile, I also ordered a random cap-with-gauge, new old stock, that I knew to be at least long enough, a "Rotary 12074"
Then I disassembled it and shortened its supporting wires to match the depth of my fuel tank.
Then I re-twisted the center sprial to adjust the full and empty points to match the new range of travel.
Then I tried to screw it on, but it was too large.
The Rotary cap is like 2.25" ID with a metric Modulus 5 buttress thread.
The Ingersoll cap is more like 1.738" ID with a metric Moduls 4 "normal" thread.
So I sleeved some 1 1/2 PVC inside some 2" pvc pipe, and that gave me a thick-walled base to cut a bushing out of.
PVC prbabably isn't ideal, but hopefully it'll last until the new fuel gauge is in.
My old lathe is in imperial only, but by creating a custom set of 5 or 6 bull gears and using an Excel spreadsheet to look up the combinations I need, I can cut metric threads to within 99.8% of perfect. My total cost was about $10 and a couple hours cutting some gears. See here for details if you're curious: https://www.youtube.com/watch?v=Kx5IsPdTzoc&t=2s
But as it turns out, metric Modulus 5 is 99.7% the same as 5 TPI, plenty close enough for this soft plastic to screw all the way on.
AND 6.5TPI is 99% the same as metric Modulus 4. Again, that's close enough.
So I set the lathe to 5 tpi and cut the OD threads. I kep trying as I went, making them a snug fit. I want the bushing to be tight in the cap itself, and stay stuck up in the cap.
Then I cut 6.5tpi threads on the ID.
Finally, I parted it off, and went outside and gave it a try. With about an inch in the bottom of the tank, it reads "empty", but if you shake the tractor, the needle moves. So it's an "actual" reading, it's not sitting on the bottom stop. So far so good.
Then I fill the tank up, (um... "past full" just a bit?) and now the cap reads "over full".
Perfect!
I threaded enough PVC to make two more bushings. If anyone wants me to send them a bushing, just let me know.
Bob
The black gas caps with the built-in guage are ok, but a real fuel guage is what I really want.
So I've ordered one from AliExpress, for about $22, both sender and gauge itself, and I'll install it... this spring some time.
Meanwhile, I also ordered a random cap-with-gauge, new old stock, that I knew to be at least long enough, a "Rotary 12074"
Then I disassembled it and shortened its supporting wires to match the depth of my fuel tank.
Then I re-twisted the center sprial to adjust the full and empty points to match the new range of travel.
Then I tried to screw it on, but it was too large.
The Rotary cap is like 2.25" ID with a metric Modulus 5 buttress thread.
The Ingersoll cap is more like 1.738" ID with a metric Moduls 4 "normal" thread.
So I sleeved some 1 1/2 PVC inside some 2" pvc pipe, and that gave me a thick-walled base to cut a bushing out of.
PVC prbabably isn't ideal, but hopefully it'll last until the new fuel gauge is in.
My old lathe is in imperial only, but by creating a custom set of 5 or 6 bull gears and using an Excel spreadsheet to look up the combinations I need, I can cut metric threads to within 99.8% of perfect. My total cost was about $10 and a couple hours cutting some gears. See here for details if you're curious: https://www.youtube.com/watch?v=Kx5IsPdTzoc&t=2s
But as it turns out, metric Modulus 5 is 99.7% the same as 5 TPI, plenty close enough for this soft plastic to screw all the way on.
AND 6.5TPI is 99% the same as metric Modulus 4. Again, that's close enough.
So I set the lathe to 5 tpi and cut the OD threads. I kep trying as I went, making them a snug fit. I want the bushing to be tight in the cap itself, and stay stuck up in the cap.
Then I cut 6.5tpi threads on the ID.
Finally, I parted it off, and went outside and gave it a try. With about an inch in the bottom of the tank, it reads "empty", but if you shake the tractor, the needle moves. So it's an "actual" reading, it's not sitting on the bottom stop. So far so good.
Then I fill the tank up, (um... "past full" just a bit?) and now the cap reads "over full".
Perfect!
I threaded enough PVC to make two more bushings. If anyone wants me to send them a bushing, just let me know.
Bob