Oil line repair question

[Jens]

On my 20/2, the oil line going from the gallery to the crankshaft central bearing has cracked straight through. It appears to me that this was a metal fatigue failure. It happened at a bend in the line.
Has anyone run into this problem before with this particular section of steel line ? In other words, would it be likely to fail again if I replaced the line with a similar line .... or would I be better off installing some kind of flexible line ?
If you have replaced the line, did you purchase a replacement part or did you purchase stock steel line of some kind and make up your own? If you made up your own, how difficult was brazing the ends without blowing through the thin line ? Would standard steel brake line be suitable for this or is there a better alternative ?  Would brazing a sleeve over the break be sufficient of a fix ?

[Westcliffe01]

I suggest Monel (copper nickel) line for the best toughness.

http://store.fedhillusa.com/316475mmtubingandnuts.aspx

[mobile_bob]

there are a few options for flexible lines as well, and i would investigate using one of them

look for "parker" push lock products

they are used inside the jake heads of cummins L10 and M11 engines, where oil pressure is much higher
and temperatures are also much higher than what you will be dealing with.

they never give up, or so it seems from what i have seen.

likely the reason yours gave up is there is no adequate support for the line midway from the source to the end use.
vibration work hardens and the line breaks.

if you have room go with the push lock hose option,

another option is the plastic "synflex" line, it can take all the pressure you have and also handle the temperatures
and would be impervious to vibration, thinner id to od ratio similar to the steel line makes it easy to fit into tight places
just use "DOT" approved ferrule fittings and you will be golden.

there are the two options i would use if i were you

bob g

[cujet]

In the aviation world, there is a new method of handling motion with regard to flexible lines. Rather than use hoses that can fail, we are using coiled stainless tubing. It's 100% reliable, never seeps and will withstand a lifetime of flexure without failure.

The lister on the other hand, has components made from the worst possible alloys. They are going to fail, sooner or later, just because the quality is so low. Replacement with anything even remotely resembling American quality steel will result in long life. Brake lines would do just fine.

The oil line to the center bearing is really not necessary at all. I have been thinking about using a funnel above the bearing, as it would collect oil and provide it to the bearing by gravity. The oil pump could be used to simply fill the funnel. I suspect that it would only need to be about 1 inch in diameter.

Chris