Silicone Oil Hoses?

Happy New Year to You Roger,

Just curious; Teflon hose - what are the advantages, over regular hose?

I get that the cost is prohibitive, so likly not cost effective.😈

Hi Sean,

Happy New Year to you.

Well it can go ten years and then on condition. Just like the fuel hoses to the carbs from Rotax. I can do a lot of fuel and oil hose changes for the cost of Teflon hose, but some like and to each his own. It's just money.  😏

I have Teflon hoses on all oil and fuel lines, all with AN fittings. I fail to see why the perceived high cost. I just purchase them from high quality race car outfits, (there are even some good manufacturers in Australia, and I feel better about supporting local manufacturers) and the cost is quite reasonable and comparable to the Rotax stuff. 

Hi friend Murray,

"...the cost is quite reasonable and comparable to the Rotax stuff."

Comparing a similar functioning product, acquisition cost to the Rotax equivalent, will nearly always go against Rotax. If you compare the price from other vendors, less likly to be so well defined.

There are are two parts to my curiosity about Teflon hoses;

Benefits ?

So far, the only benefit, I have deduced from the "proponents" is that they last longer than the traditional rubber.

Are there other significant benefits?

Cost ?

I have not explored this product, however many allude to high cost.

I  am always interest in  the Cost : Benefit ratio of any product. That doesn't mean that I wont purchase an item, where the cost out ways the benefit but its pretty unlikly.

😈

Reading this thread reminds me of how some SLSA manufacturers did not even get the basics correct when it comes to hoses. Forget whether they were silicone, rubber or teflon, they often came with an array of mismatched fittings that were incompatible or over / undersized for the hose used. 

This was quite apparent with the early 912iS powered aircraft as manufacturers struggled to understand and build hoses for the high pressure fuel systems.  I’ve seen factory aircraft with AN6 braided fuel line that has an AN6 connector on one end and a metric DN10 connector stuffed on the other - not with an adapter, just mounted directly to the hose. Yes it worked, but now you have a hose that is impossible to replace since those connectors don’t belong on the same hose.

So as an owner you we’re stuck with an engine that has fuel rail and fuel pump connectors set up for DN, and everything in between (fuel filters, check valves, selector valves) set up for AN.  The only proper fix for USA based aircraft is to replace the fuel rails and fuel pump hardware with those with AN fittings. Rotax sells them, but for the injected engine that cost can be over $1,000, plus technically you need a letter of authorization from the aircraft manufacturer.  To me this is one of the biggest downfalls of the ASTM process - the manufacturer can build something wrong and that somehow passes, but then you need their permission to fix it.  

Later on manufacturers realized they could order engines from Rotax set up with AN fittings, but still some manufacturers did not and kept building aircraft with a mix of AN and DN fittings. Seeing this stuff does not inspire confidence in the ASTM process.