Wednesday, January 25, 2012

External oil return fittings

Here I drilled and tapped for the external return line fittings on the lower case. The other end of the lines starts at the heads; instead of returning the oil from the heads to the case through a passage in the cylinder wall, it will now return via oil lines which will allow the oil to remain 20-30* cooler than the OEM set up.

Hole started with a center punch, about to pilot drilled:

Holes drilled with a letter "R" bit:

1/8" 27TPI tap:


1 comment:

  1. Hi Brad, I'm considering doing an external oil lines mod on a bike I'm working on. I am actually taking an oil cooler out of the loop. I'd really appreciate it if you could tell me where or how you got the info that says you'll run 20-30 degrees cooler using your external oil lines rather than internal.
    Thanks, great build by the way.