Silicone Heat exchanger pipes!

[easy]

Hi Guys n gals,

Just wondering if this is even possible due to the heat a proximity of the exhaust, but has anyone ever used the high heat silicone pipes from heat exhangers? Is this even possible? what are your thoughts? has it been done or is it just a massive no! you can get some uber high heat silicone pipes, just wondering if its possible instead of the pain in the arse aluminimum foil ones!

 

[gas1man]

Had the same problem , so sourced some aluminium flue , if I remember correctly it was 80mm.
Put on and used large hose clips that pulled them tight. I then wrapped them in exhaust wrap and I did
the heat exchangers with exhaust wrap after painting at the same time.




You can see them just ahead of the heat exchangers. May help with an idea.

J & P

 

[easy]

Cheers dood, that pretty much what i have on mine, i was just wondering if there is such a thing as silicone tubing that can handle that sort of heat i.e next to the exhaust, i guess there isnt unless its a bazillion pounds!

 

[NigelDenham]

If you’re talking about replacing the concertina connectors from the exchangers to heating ”system” (I use the word with a slight smirk), I used some temporarily whilst sourcing some originals, and it worked fine. It is the stuff used on turbo intercoolers etc. it really didn’t want to bend to shape though. However, its expensive, I think I could have just bought some repro concertinas for not much more.
I think the rubber seals used on t25 exchangers are silicon instead of the old asbestos bay types, so obviously they manage the heat. They’re not really in direct contact with the exhaust pipes themselves are they.

 

[easy]

its a good call, i may have a little looksy but i do have a feeling they would not be as flexible as they should be i guess and may start to work loose over time. hmmm

 

[NigelDenham]

They’re definitely not that flexible. Seemed ok once I did get them on and didn’t move, though they were only on for a month or so until I sorted some OE tubes with insulation inside. I don’t think I’d do it again to be honest unless I had no alternative.

 

[bmxburner]

You can see rough exhaust temps here on ratwell. Based on this I bought some of this hose from their amazon shop. Needs to be the more substantial 2-ply I think. I connect this directly to my exhaust with big hose clamps, so I can have it running inside and still route fumes out of the garage. It's very flexible and I don't see why it couldn't do what you need.

 

[easy]

Ace, will take a looksy, cheers dood

 

[purpledog07]

I replaced the OG style card/foil hoses from the heat exchanger to the fan housing with eberspacher branded heater hose, it's similar in looks, black satin finish, much tougher, but could still be shaped around my aftermarket 4 into 1 collector exhaust.
For the larger, concertina heater tubes in front of the engine going to the 'Y' piece on the van you can't really beat the originals. I am running OG's on a 1600 type 1 engined '72 and the heat at the cab vents is incredible.
Let us know what you plump for and how it works out.

 

[NigelDenham]

I replaced the OG style card/foil hoses from the heat exchanger to the fan housing with eberspacher branded heater hose, it's similar in looks, black satin finish, much tougher, but could still be shaped around my aftermarket 4 into 1 collector exhaust.
For the larger, concertina heater tubes in front of the engine going to the 'Y' piece on the van you can't really beat the originals. I am running OG's on a 1600 type 1 engined '72 and the heat at the cab vents is incredible.
Let us know what you plump for and how it works out.

I totally agree about original insulated concertina tubes, definitely the best. I might have a look at the heater hose you recommend as I have had to continue the fan hose straight to my heat exchangers and the exhaust header is right in the way, had to ‘dent‘ the tube to do it

 

[purpledog07]

Mine is fitted the same, ovalled around the exhaust pipe and straight through with some rubber edging trim around the tinware holes.
I wonder if anyone has ever managed to get the original steel tube connectors that go through the tinware to sit right and look OK. The original style seals are awful too, they just dont seal anything. It all ended up a loose fit and wonky looking when I did mine as original.
I ran the old style card/foil hose straight through and that was fine. Replaced it with the eberspacher diesel heater hose when i had everything apart fitting twin carbs and new rear tin anyway.
This hose is used to distribute the hot air from the engine room to seating in cabins or on the cockpit or flybridge on yachts.
I aquired mine from a job at work but I'm sure it's readily available to buy.
I work on motor yachts and when we need eberspacher parts/spares they are often sourced from a place called "espray" in Plymouth. They probably aren't the cheapest as luxury yacht owners aren't that frugal generally, so worth shopping around.
Hope this helps. I did consider the silicone type wire wound hoses myself

 

[purpledog07]

but I'm not sure if they can be shaped to fit like the heater hose can + the heater hose looks OG but better quality with a slight sheen. Can be wiped clean too, it won't absorb oil or fuel and won't scuff up like the card ones if wetted and wiped.

 

[NigelDenham]

Thanks for the tip. My issue was with the small, what I assume to be pre-heater cans on a standard type exhaust Not lining up at all with the tinware holes and heat exchangers (which I believe is a common problem with any of the pattern silencers?). There was so many gaps I lost most of the warm air to the cab. So I removed them completely and just run the tubes directly past the rear header pipes.

 

[purpledog07]

Ah, I know the cans you mean.
I fitted a new stock exhaust on a 1600sp beetle engine a while ago.
They were miles out from the tinware holes and could never fit without completely reshaping and welding more metal on. I did the same as you and just ran hose all the way. No more leaks.