Engine Plumbing: Oil Lines

I built up the oil hoses that connect between the engine oil returns and the oil tank. Per the build manual, these hoses are to be covered with a heat shield, and then secured with lock wire.

I briefly talked about the heat shield with Shawn during a recent trip to Torrance, but didn’t really get into specifics, so I had to figure some of the following for myself. First, the heat shield comes as a big sheet that’s roughly 1×2 yards. I cut some 2.5 inch-wide strips for the hose wrap, which is wound around the hose in a spiral fashion. To make it easier to wrap tightly, I used a small wooden block to spool up the heat shield.

Spiral wrapping heat shield around oil hoses

Next was figuring out how to wrap the lock wire. The wire secures the heat shield and should be spiraled around at the opposite angle to the heat shield – easy enough. However, I wasn’t too sure what to do at the ends of the lock wire. Normally when lock wire is installed, the two wire ends meet up and get twisted together. But in this case, I had only a single end to work with at each end of the hose. My solution was to pass the lock wire through one ear of the hose clamp, double the lock wire over itself, and then twist it together – this seems to secure it nicely.

Spiraling the lock wire over the heat shield
Looping one end of the lock wire through the hose clamp ear
After twisting the lock wire
Completed hose assembly

To install the left side hose the build manual states the #4 exhaust tube must be temporarily removed, then the hose can be attached to the oil returns on the bottom of the engine block. I suspected, but didn’t know for sure that oil was going to spill out when I removed the cap from the engine, that was a bit of a surprise.

Access is tight even with the exhaust tube removed. The hose end is tightened with a 22mm spanner to 25nm torque. A while ago I bought a set of SAE crows feet for my torque wrench, but none were the correct size to fit over the nut of the hose end. I didn’t have the patience to order and then wait for a metric set, so I just modified a 3/4” foot with my bench grinder to open it up to 22mm. Access for the right side hose was even tighter, though it was not necessary to remove anything.

Hose end attached to the left side oil drain
3/4 inch no longer, this is now a 22mm crows foot
Routing of the right side oil return line

I have a few more hoses to build, including the turbo supply line and radiator lines, then I can build up the stand-offs to secure these hoses.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.