Hard Lines Vs. Rubber Hose

Building Stainless Steel Oil Lines for Your V-Twin

This area could certainly use some cleaning up. With a little bit of brainpower and some elbow grease, we should be able to transform the looks into something more attractive.

First thing's first. We removed the exhaust system, drained the oil, and removed the existing oil lines.

Before the oil lines were removed from the bike, a sketch was made showing the origination and destination points of all the lines. This way we could be sure the new lines all ended up in the right locations.

Hotch indicated with a hex key the existing oil pump feed location. For cosmetic reasons, he moved it to the port he pointed out by his left index finger. We didn't forget to plug the hole left by removal of the fitting.

We didn't skimp when it came to the fittings. Hotch uses Swagelok brand fittings exclusively. He always has a good supply of polished fittings (90s, 45s, and straights) on hand. You will need to determine what fittings you will need and have them polished before you begin your project. Each fitting is made up of the following pieces: (left to right) straight connector, front ferrule, back ferrule, and nut.

A little bit of Loctite Pneumatic/Hydraulic Seal is all it took to keep the threads from leaking.

Prior to installing the fittings, we used a 1/8-inch pipe tap with a little grease on it to chase the threads. We didn't cut the threads any deeper than they were; we just used the tap to be sure they were clean.

Once we determined what path each line would take, we installed all the fittings so they would face the proper direction. To tighten some of the fittings, we needed to screw the nut in place in order to get a wrench on it.

Hotch ran into a problem when he got to the oil filter. The distance between the two threaded holes was too close together to allow clearance for the second fitting to spin freely.

To get around this problem, a small 90, with 1/8-inch male threads on one end and female threads on the other end, was used to allow insertion of a straight fitting to complete the line running to the oil filter inlet.

OK, on to the tubing. Hotch determined the routing of all the lines and took a measurement of the length of the vent line. He added about 4 inches to his final measurement and cut a piece of 3/8-inch 0.035 wall tubing with a cut-off wheel. Hotch does not recommend the use of a tubing cutter on stainless steel, due to the fact that the tough tubing will dull the cutting wheel very quickly.

Ahhh, tools. Did we mention we love tools? This Rigid tubing bender is designed to bend 3/8-inch tubing, and nothing but 3/8-inch tubing. It is very sturdy, has long handles for easier bending, and will give consistent results.

A piece of tubing was inserted in the case fitting while Hotch held another piece against it to indicate where it needed to be bent.

The tubing went in the bender and got an initial bend before Hotch held it in place to see if he had the proper angle.

The finished length was marked on the other end before...

..both ends got trimmed on the band saw.

This tool is used to remove the burrs from the inside as well as the outside of the tubing. Deburring can also be done with a belt sander and a countersink.

All of the additional tubing was bent to follow the lines of our first piece. Here, Hotch used a small bend gauge (in his left hand) that he made to help him determine where to position the tube in the bender so the bend would be in the correct location.

This line needed a slight offset, so the end of the tube was rotated a little in the bender.

Hotch inserted a piece of tubing in the oil pump feed fitting to help him visually align where the tube needed to be bent.

With a successful bend in the tube, the finished length was marked, and the tube was cut.

According to Hotch, this is the tough one, referring to the line connecting the oil filter return to the oil bag. It is the longest one of the bunch, has five separate bends, and needed to match up with the other lines.

Just take your time, and think about what you're doing before you do it.

Once again, we used another piece of tube to help line up our bends.

Before the job started, Hotch sent all the fittings out to Manuel Banda at Superior Custom Metal Polishing. Banda turned the dull gray finish of the fittings into a mirror-like shine.

Once all the tubing was bent and Hotch was satisfied with the fit, he sent the lines out to be polished. Just as he did with the fittings, Banda made 'em shine.

When the tubing returned from polishing it needed to be cleaned inside and out to remove the polishing compound. A little bit of brake cleaner followed by some compressed air, and everything was ready to go.

Using a flare nut wrench allowed us to tighten the nuts properly and keep us from marring the surface of the fittings.

After all the lines were tightened, they could be muscled around a little bit for final alignment.

We filled the oil tank with oil and loosened one of the oil line fittings to help get the air out of the system; then fired up the bike and checked for leaks and proper oil pressure.

When it was all said and done, these new lines looked far better than the rubber ones they replaced.

After studying the appearance of our Titan Coyote, we came to the conclusion that the engine department could use a little spicing up. The stock oil lines on this bike are of the black rubber persuasion, and while there was nothing wrong with them, they just blended in to the motor and transmission and got lost. To remedy this, we decided to do an oil line conversion to add a little visual appeal. Granted, hard lines would easily outlast their rubber counterparts, but that was not our motivation. We thought we could add to the bike's looks by adding a series of parallel and perpendicular stainless steel lines.

Since Matt Hotch, of Hot Match Custom Cycles, located in Fullerton, California, has made hard stainless steel oil lines one of the signature features of his bikes, we figured he would be just the guy to build them for us.

A couple of hints from Hotch before we get started: "Use only high-quality stainless steel fittings and tubing. Do not use copper tubing --it will break. Take your time as you bend the tubing, and check your measurements twice before you bend. This is a very visual process -- watch what you are doing. Start with about 20 feet of tubing because you will make some mistakes."