When I did my coolant reroute I decided to fabricate a hard pipe for the water return from the back of the head to the radiator. That aluminum pipe gets hot and is located only a few inches away from my air intake, which undoubtedly increases my IAT values. Long term I plan to go with a cold air box. Until then, I'm running a large open element filter and am looking for ways to insulate this aluminum pipe. I'm looking for recommendations on what product to choose. Pipe outside diameter is 1.25"

Most of the heat sleeves I've seen at Summit Racing, JEGS, Pegasus, etc. are meant to protect vital components like wiring harnesses, fuel hoses, brake hoses and rubber coolant hoses from nearby radiant heat sources like turbochargers and exhaust pipes. They're typically made of either corrugated aluminum tube or aluminized fabric or silicone rubber with a woven fiberglass liner. They conform to bends with varying ability. Some are seamless, some use velcro closures. How well do these products work when the heat flux is in the opposite direction?

 

Reflective surfaces for reducing radiant heat work equally well in both directions.

Radiant heat flux increases with the fourth power of temperature, so it's much less of a dominant effect for ~200F coolant than for a turbine.

Do you have data showing high IATs as the engine and coolant heat soaks? Maybe before and after adding a Crusher-style air barrier? That might be all you need, since air on the cold side hasn't had much chance to be heated.

 

No I don't have any IAT data. Just got the car started for the first time and starting to tune and datalog. I was just planning ahead. The car is located far away and I only get to work on it sporadically, which means lots of time to think in between intense periods of activity actually working on it.

So you're saying just wrap some gold or silver reflective heat tape around the pipe? And/or fabricate a physical barrier?

 

heat shield/barrier like above looks to me like a clear winner here

 

I think logging IATs before and after adding a barrier is the best use of time. Keep the intake air from passing over hot stuff. Won't know what's effective without logs.

Air also doesn't absorb much radiant heat directly, so reflective stuff is very much a second-order effect for heating air (unless you're wrapping a charge pipe or intake tract on the outside).

 

You could polish that pipe to eliminate some radiant transfer.

The big one though is not radiant from a relatively low temp (water is what, 160F versus exhaust at an order of magnitude more) but probably convection under the hood. Stuff doesn't cool well when ambient temps are really hot. And hot air gets sucked in very easily.

 

Here's what I used for this very problem...

Cheap pipe insulator from Bauhaus. That would be Lowe's for you guys.
Works like a charm.







Obviously, I was mocking up the pipe/hose layout as I took the pics.

Thought this might help.

 

looks pretty clean, nice work. what type of claps are those on the coolant reroute? they look corrugated. never seen that before.

 

Look on McMaster. They have a huge selection of sleeve's and pupr insulators.

 

Constant Tension Turbo Seal Clamps TSS | Murray Corp

 

I'd skip the stuff we have over here, which is typically polyethylene foam, starts to melt about 200°F, NFG. We do have the white and yellow stuff which is fiberglass with a paper backing which should be fine but that **** will eventually make a mess rubbing on hose clamps and ****.

 

I actually took a heat gun to the heat sleeve I used to see if it would melt and ruin the engine bay.
It did not.
Also, it has been quite a while since I installed the heat sleeves, no problems so far.