I know, I know. This has been talked about alot. But what I want here is something very specific. I want to know:

a) if anyone who has silicon hoses has seen ANY degredation (cracking, etc). Or,

b) if you have had silicon hoses for 5 years or more and haven't seen any degredation, I'd like to know that too.

(If you have had them for less than 5 years and have had no problems, that's great but it doesn't really tell me anything ). I'm trying to decide if Viton is really worth the $$$.

 

i used viton. i think its not really worth it.
it split as easy as silicon.
but after several months, it still looking like new in terms of shape, and feel.
the silicon feels soft the viton feels as stiff as new...
I used 70A hardness not the 60A.

reza

 

I have some hoses in my car that are over a year old, and some that are 4-5 months old, no difference in feel or texture between the two.

 

reza: when did it split? when you were installing it? Isn't the silicon a bit softer anyway?

nameless: I assume you are talking about silicone?

(Thanks for the responses by the way)

 

well within days of installing it, one hose split. I remember that I nick the rubber when installing it.
But I pull on it, and it does not split.
so several days after install, i got a high idle. So i look in, and it has split

reza

 

Here's a handy dandy chart for comparing them:

www.McMasterCarr.com

Click on Rubber Tubing.

The absolute best silcone tubing you can buy is called DuroBlu, but it is only available in 1000 foot reels. It's the only silicone tubing I am aware of that meets mil. spec standards - that means you can put it in an airplane and fly with it without worrying about it coming apart. Just make sure you don't use silicone to carry oil, it was not designed for it.

You can buy it by the foot from:

www.rxforyour7.com

Jay has spent 30 years working on rotaries - he knows what works - period.

 

RonKMiller - re the linked site for the hose:

Help me out here...for the hose job we require diff size hose correct? Does your seller offer this?

Thanks oh wise one.

 

HAHA... Oh ****, now I'm like Gandolf!

Probably the best thing about this hose is not only does it resist kinking (which is a major problem on some of the very tight, small radius turns you need to make) it is also very elastic, meaning you don't need different sizes to fit the nipples. It also has a fairly low durometer rating which means it is soft, so it "grips" well. I would still use a LITTLE 3M weatherstripping adhesive (the yellow stuff) to hold it in place. A LITTLE adhesive is ALWAYS stronger, plus you don't want any excess actually getting inside the hose. Nylon ties are not necessary, even on the pipes withought ridges.

It's that good.

So, no - all you need is 25 ft. I would get 30 since I always like to have a little extra and have been known to screw up on more than one occasion.

 

So all a person needs is 25 feet of 3.5 mm? How come the kits have 40 ft of 3.5mm , 16 ft of 4mm, 12ft of 6mm and 4 ft of 8mm? Do I need to change the bigger ones or is it the 3.5 that will be the cooked ones?

 

ronk,
your talking about the silicone hose right? i just asked on another thread why the hose techniques kit comes w/ so much hose and all diff sizes. i saw on robinette's site that all you really need is 35ft of 4mm and 15ft of 6mm. but if your saying that it stretches than i'll go w/ the 3mm hose. thanks for your help.
nick

 

I did this about a year ago I guess. I used the Hosetechniques silicon hose. I only used two sizes. There are a couple places were another size would have been nice but it works just fine.

I think this whole viton vs silicon boils down to the difference between theory and practice. One shop put some silicon hose in my car that was about .030 wall and it held up for over a year. The stuff from hose techniques is so thick I think it would take years to be disolved. Viton is about 5 times more exspensive and does not rate any higher for mechanical abrasion. Rubbing is at least as likely to take out the vac hose that oil or heat cycling. That's why Goodyear vac hose has an abrasion resistant covering.
WFIW I check the hose right by my turbos last weekend and there is not evidence of heat degradation. In theory Viton is better but in practice the actual failure mechanisms may not be related to chemical resistance.

 

For some reason, every shop around here has standard sizes. Has anyone else found this? 3mm hose is pretty much 1/8". I guess a guy could use 1/4 for the 6mm? Anybody do this or should i buy the metric?

 

About 4 years, 40k miles later, and a bit of FL heat.
I use AroSpeed hoses.
Although arospeed can commonly be associated with ricey stuff, they sell damn good silicone hoses. They have a thick side wall to prevent kicking. I can bend a 2" piece into a complete U-turn, and it still won't kink.

I've taken my UIM off about 3 times, inspected hoses each time, and all are still in excellent shape.

 

Thanks Flybye. That's one definite data point.

Anyone else?

 

If you are worried about oil causing silicone hose to break down (the reason some people use viton) the rats nest is not really the place to look. About 1/2 the hoses are behind check valves and only see vacuum. Most of the hoses that see boost only work "dead-end" acuators (i.e. CRV, ACV, ERG, Fuel pressure regulator, etc.etc.) and so the hoses will see very little "contaminated" air.

If you have good non-leaky turbos and a catch can, the amount of oil in the manifold air should be very small. In real life, you'll pull some intake pipes off, see oil covering the inside of everything, read http://www.geocities.com/MotorCity/G...5/hosetest.pdf, panic and buy viton.

The hoses that IMHO are most likely to see oil will be the crankcase ventilation hoses. The short ones the PCV value attaches to (if you still have it) and the short pieces leading to the intake elbow on the the primary turbo.
I'd like to see someone who put silicone here a few years ago pull the PCV hose and swab the inside with a Q-tip and report what he/she finds.

The second most likely will be the hoses for wastegate and turbo precontrol since boost pressure is allowed to escape by the solenoids

 

Good points flunkysama.

(sneaky bump )

 

Ok (bump), one more time. I'm just looking for a single data point; anyone who has had silicone hoses for around 5 years (or more) and who hasn't seen degrading due to oil.