Peel's OIF frame is to gain room for other stuff and open up the view thru bike. Removed about 6 lb of stuff under seat -replaced with less than a pound of fittings and oil mass shifted forward. By using the lower frame tubes as feed and return routes - eliminated ugy hoses by a few inches of steel oil tube silver soldered up snug to frame. Only the red handle manual fail safe shut off valve sticks out from frame to reach towards oil manifold. Room to place pre-filter too. Holes made in spots already braced by over lapping gussets and being silver soldered in add back their own support not take away.
Venting w/o a mess on various bike angles is tricky part, plus to get enough volume to cool in time to recycle. I know Peel's OIF surface exposed to wind is greater than tank tucked up under behind plates/cover.
I had hard time to get oil over 130'F, illegal ridding speeds and throttle and took life risking angry wild Squid Spanking WOT Redlining over 45 min 75 miles in mid day mid summer swelter to see max of 195'F with oil tank set up. I may have to insulate spine tube or run less oil if can't hit like 160'f on hot high way runs.
Ran back home at mild 80-90 mph on 55 hwy and saw 125' F again in 90 seconds.
Here's two views of Peel in the raw OIF.
Oil fill near stem Al cap with one way in gold MX gas tank vent to relieve low pressure and prevents crash spills.
Oil drains bottom center of spine via a steel tube elbow that cleaves to the rear gusset then pierces RH down tube above where gusset down curve lands on frame.
Oil descends to triangle gusset level where steel tube with valve exits frame.
This feed tube must miss Z plates and fasteners and manifold hoses. Handle gets in way of both kicker and foot peg when out. Folds forward inside of engine cases. Fail safe anti-sump fix.
Oil leaves engine manifold to go thru filter between rear verticals, 4" under the check valve seen sticking out in triangle gusset level. [That's an Al bar/nut seen between frame tubes as the filter/air station support brace, not oil path tube]
Oil goes through LH frame up into spine via 2" steel tube welded on L stem.
A two way flowing 2nd connection is made to LH feed tube via a sight tube on brass barb fittings. Allows nose low oil flow to engine, unless upside down and then too till a quart or so leaks out somewhere like exhaust maybe.
Set up should allow vertical states and climb outs with plenty of oil head over pump. Only exit of blow by to ambient is via exhaust eductor.
There are two unsealed areas in Peel '72 frame, worse at the hidden junction of the under tube and mid spine gusset. Patch of Iron Putty is seen as light area there. Other pair of leaks are at tops ends of tubes between the shock mount plates, needed Iron Putty stuffed hard in the top. Hold tongue to valve now with some suction till tongue gets a hicky. Will pressure test before painting.
Check valve is just hung in place in photo, later JB cold Welded in. IS Gas tank had to be mounted 3/4" to rear - just as it fouls the mid tube flair, but just right luck out again for filler size I had found in light Al. Shiny thing at bottom of carpenter square rust piece is a super magnet. It may stay there to pull ferric particles away from oil out let on other side of tube. Oh yeah drains at bottom of each rear bend just above hi center snags. No mess if a tray put under and left alone. I won't miss that part of Commando oil tank.