making rocker oil lines

PTFE I thought and same as brake lines, I had the nylon until one end popped off luckily while I was tuning the idle and have been stainless braided ever since.

MikeG said:

I took it one step beyond braided lines. Drill the inlet valve rocker shafts and do away with the crossover line altogether. Use the now unused left fitting to hook up an oil pressure gauge.

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For the single line like Mike mentions use braided brake line - go to:

Paragon performance 800 270 0333 single line 26” 8mm one side straight the other bent 30 deg, 90 deg offset.

Cheap at about $30

Drill one rocker spindle - then you can eliminate the crossover oil line and plug the empty hole with the same kind of allen bolt that holds on the head steady (add alum washer).

See this video for spindle drilling:

One thing that no one has mentioned on this thread [or others I have read on this subject] is the installation of an oil restrictor. This is a common modification on light aircraft engines. A plug with a .040" hole drilled into it, is installed at the feed end of the hose/pipe assembly going to a mechanical oil pressure gauge. The purpose of this device is to slow the loss of oil, should the gauge or the hose feeding it leak. It could be the difference between a messy bike and a blown engine.
There are commercially available AN3 & AN4 fittings with a restrictor in them. See

http://www.aircraftspruce.com/catalog/eppages/oilfuelflow05-11908.php

Most owners simply insert a universal [domed head] aluminum rivet into a fitting and drill the .040" hole. Using SS braided hose and Jims "single hose" mod, this is easily accomplished. Simply press a brass/aluminum or steel plug into the left side banjo bolt feeding the gauge. Drill the .040" hole into that plug. When using a nylon hose ported to both sides of the head, you need to install a "dual line" fitting [stock on the right side] to the left side of the head. Here, you could simply braze shut the second barbed fitting of that fitting, then drill the restriction into it. Obviously, this needs to be done before the nylon tubing is installed.
Make sure that you are only restricting the oil flow to the gauge, not the rocker shafts.

Charlie

Anglophile said:

Aren’t braided steel lines simply nylon lines with a braided sleeve? If so it too could become brittle and leak. Not as fast a rate but it would, wouldn’t it?

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My guess is that the inner lining, like that of braided-stainless brake lines, is teflon, which is much better than nylon for this use.

texasSlick said:

I have some 5/32" nylon tubing in my shop since the 80's. It has not become brittle .... looks and feels like new.

Perhaps, the condition of my tubing is due to intended air use, or quality. I got mine from specialty hydraulic/pneumatic suppliers, not the local discount shop.

I would worry over the temperature rating. Perhaps those who got hot oil on their pant legs used air line stuff, while those who report no problems are using the hydraulic high temp grade. As far as I know, one cannot tell one from the other by sight. It may be the stuff is branded with a rating now-a-days.

Slick

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Air line will say it's DOT approved every foot or so. Don't know about the other stuff.