Ljet vacuum hose, Any scuba divers on this site? Options

[timothy_nd28]

In the process of re-doing vacuum lines on my 1.8L Ljet. The vacuum line that has given me trouble before is the 22mm (blue in picture) which I cobbled together with less than desirable results.


I'm toying with the idea of using a hose from most scuba setups, the BCD corrugated inflator hose. It is rubber of some type, the ID diameter appears to be very similar, and I like the idea that it looks very flexible so it can be routed to look somewhat stock vs what I had before. Question is, what is this made out of, and how will it hold up?

[wonkipop]

went through this a year ago.
porsche australia supplied all hoses to do fuel lines/vacuum lines for my 74 1.8 - except the pcv valve hose. they said unobtainable. even as hose.
no brand name stamped into hoses supplied as far as i remember or can see.
just came in a porsche bag.
(prices were reasonable and its almost impossible to source this yarn woven hose at retailers these days, aftermarket has seemingly gone over to nylon braided everywhere).

i did some research and came up with Cohline who are an oem supplier for Audi. they produce oil and vacuum hose. type 2620. NBR inside with yarn braiding. comes in DIN size 20 = 22mm ID 30mm OD.
has an internal reinforcing with steel wire.
as far as i can tell the original pcv valve hose is not internally reinforced.

there is another alternative they offer which is vulcanised yarn braided fuel line type 2122.
unreinforced internally according to website catalogue.
i've got a feeling this is the vacuum line hose that porsche supply - given the audi link?
problem is the nearest size in that has an ID 25mm. so would need to be clamped at connections. might be why porsche would not supply or claimed nothing at required diam.

i still run my original pcv hose. its ok/still sealing. the bends are 45 immediately after the pcv valve tube and before the plastic intake boot tube. i don't believe it was preformed but i could be wrong - it might just have taken the shape after 46 years - several other of the vacuum hoses removed have retained shape even off the car.

if its anything like the hose running from the charcoal can to the aircleaner, which is the next biggest hose on the engine, then its capable of doing the sharpish (45deg) bends, without collapsing and without stressing the connections into the pcv valve and the air intake boot. that new hose i put on to the aircleaner is very bendable without collapsing or kinking.

as an observation. all the original vacuum lines i pulled off were rigid with age.
the new stuff is extremely flexible. the original pcv valve hose is very rigid with age and it might be it gives the impression it is preformed. i don't think it was like that new.