Article By: Wayne At Wicked Willy’s Choppers www.wickedwillychoppers.com
In part ten of the beer runner, we will build an oil tank for the trike. It is a very simple tank that will mount inside the swingarm, but it will be built just like any other tank we build for a dry sump motor. It will have a feed line, return line, and a vent line. We will be building it from 14 gauge steel since it will be mounted inside the swingarm and hopefully will not have a problem from cracking from the stress of the swingarm bouncing when the trike is ridden.
I am going to build a simple square tank that holds three quarts of oil, so I think the easiest way is to measure around three quarts of oil. From this measurement I will cut my steel plates that I will make my oil tank from. There will be no question of how much oil my tank will hold.
Here you can see where I am going to place my oil tank when it’s finished. I take the measurements for my steel making sure it will fit where I want to put it. Nothing’s worse than to fab something and then find out it just will not fit.
After I have my plates cut, I then cut four pieces of ¾ round stock to machine my oil fittings from. These will be welded in our oil tank.
Here are my oil fittings after I machined them. I drilled a number Q hole all the way through the pieces and tapped them 1/8 NPT (1/8 pipe thread). Also note I machined one end down to ½ inch in dia. and left the shoulder ¾ inch. This will give me something to weld to with out endangering the threads I cut and will also give me a good base to keep my fittings straight.
Once I have my sides tack welded into place, I drill four half inch holes in the side of my tank. One hole is for the drain, one is for the oil pick-up, one is for the oil return and the other is for the breather vent from the motor.
Next, I take a scrap piece of 1½ inch tubing and turn down one end that will go into my oil tank as a fill tube. If you use 1½ inch tubing with .120, it will fit a stock oil filler plug. There are 2 reasons I turn down the one end. The first is so I have a surface to keep my filler tube straight. The second reason is that I want my tube to go inside the tank so I’ll know not to fill past it. This way the oil will not get into your breather and return tube and bleed back into the motor.
Here is my filler tube and the top plate I will be using for the tank. Notice that I machined a hole about .020 larger than the smallest end of my filler tube. Now my filler tube will go in and rest straight on the large end, helping to keep it straight when I weld.
Next, I use 3/8 hydraulic tubing for my vent and return tube. I measure and bend these so that they are around 3/16 of the top of my oil tank on the inside. I will weld them to two of the oil fittings that I machined earlier. This will give me the makeup for both the return and breather fitting. Because this is thin wall tubing, you must be careful not to burn through and stop up your tubing. You also want to make sure they don’t leak. I plug one end, charge the other end with air and put it into water to check for leaks.
You can see that I aim one tube inside the tank one way and the other tube the opposite way. This way you don’t have your return oil blowing inside your breather tube. Also notice the tubes go all the way to the top of the tank. They are around 3/16 from the top.
Once I have my tank all tacked together, I TIG weld my entire weld with a mild steel filler rod. The reason I use a TIG is that I want to try and control my welds as not to have pin holes. This will cause nothing but leaks for you in the long run. And I hate an oil leak.
Shown here is my simple oil tank welded up. You can see my filler tube and my fittings welded in. Just like the return and breather tubes, you can plug your fittings and give a few pounds of air pressure and place into a bucket of water. If you’re interested, the two bottom fittings are a drain and the other is for oil pick up going to your oil pump. The fitting closest to the top is for the breather tube which comes from your crankcase and the middle fitting is the oil return from your oil filter.
This is our oil tank mounted inside the swingarm for our trike. It’s under the seat where one can get to the fill tube easily. If you noticed, I bolted it in just in case I get a leak or something, that way I can unbolt it and remove it for repairs. I always try to think about what’s the easiest way to get to it for repair if something goes wrong.
If you have any questions about our oil tank or need help with one you’re building, feel free to call me at the shop at 828-303-0422 or go through Facebook. We have a page there: Wicked Willy Choppers. Our Web site will be down for awhile