Engine insulation for hybrids to improve fuel economy

[Phase]

Originally Posted by Isaac Zachary

Refelective surfaces reduce radiant heat loss. They do basically nothing for convection heat loss.

so cheapest and best solution is wrap the fiberglass in alumunim? my overall budget for insulation is 100 bucks for my hood. i care about performance and safety

[Isaac Zachary]

Originally Posted by Phase

so cheapest and best solution is wrap the fiberglass in alumunim? my overall budget for insulation is 100 bucks for my hood. i care about performance and safety

I don't know if cheapest and best can go in the same description, but if you mean best bang for buck, then probably yes. The aluminum foil would also help keep air from blowing through the fiberglass, which would also be bad.

The only problem is fiberglass works best when fluffed up. Putting anything on it to hold it down compresses it and makes it lose its R value. Maybe thick aluminum foil could cradle the fiberglass just well enough it stays fluffed up but doesn't fall off the engine.

Mineral wool would be better IMO as it tends to hold its shape better. It is also non-flammable, whereas fiberglass can catch flame after a certain temperature. Of course, if you get any oil on either and you now got a wick.

[freebeard]

Why not Dynamat or similar?

[Isaac Zachary]

Originally Posted by freebeard

Why not Dynamat or similar?

Looks like Dynamat Dynapads can only withstand temperatures up to 225°F. So you could possibly use them on the engine, but not near the exhaust parts. I'm not sure how well the insulate against heat since their main use case is for noise reduction.

[hayden55]

Boys yall are over thinking this. Just slap insulation down and see what you think first. Its $20 for a roll of R-13 and a 4' section that you will use is about $4.
I bet my piece of insulation will last the life of the car no problem from what i see so far. Underhood temps are not that high even in the summer on a v8 car which is typically the worst case scenario.

[Phase]

Asked my car buddy who works on cars this. Excuse his language. But it got me a bit worried and concerned.

I’m just looking for the safest, most stable and least messy way to insulate the top

If we just flat out ignore prices, what’s the best solution possible? What would an OEM automaker put who specializes in winter vehicles in Alaska do?

What material is not flammable? Apparently fiberglass, mineral wool, and ceramic are all bad now?

[Piwoslaw]

Something mentioned on EM are... fire blankets.
By definition non-flammable.
But does anyone know the insulation value?

[Isaac Zachary]

There is a fiberglass material on the top of the Avalon engine under the plastic decorative thingy with the engine displacement written on it.

[freebeard]

Originally Posted by Phase

If we just flat out ignore prices, what’s the best solution possible? What would an OEM automaker put who specializes in winter vehicles in Alaska do?

Do what NASA do -- Hollow glass [vacuum] microspheres.

Insulating Painting Additive Ceramic Microspheres
Cenosphere is a lightweight, inert, hollow sphere filled with inert air or gas, typically produced as a byproduct of coal combustion at thermal power plants.

www.seppe.cn/Insulating-Painting-Additive-Ceramic-Microspheres-pd6723479.html

[Isaac Zachary]

Originally Posted by Phase

If we just flat out ignore prices, what’s the best solution possible? What would an OEM automaker put who specializes in winter vehicles in Alaska do?

This:

https://www.amazon.com/Lynn-Manufact...a-870211061173

Take and make a quilt out of this stuff with either foil or space blanket material on both sides. The foil/space blanket will keep oil from wicking into the mineral wool (or ceramic fiber). The mineral wool (CF) will hold its shape and it and the foil will not ignite or melt against the exhaust. Mineral wool also tends to repel water instead of adsorbing it like fiberglass does. Just get it in there in a way that doesn't puncture it so oil doesn't get to it, that would be the trick.