Spray Foam Insulation Inside Engine Room: Bad Idea?

[Marceps]

Hi, all. I would like to apply two-part, closed-cell spray foam insulation to the walls inside my rear-engine compartment. Tiger Foam states their product is rated to withstand temperatures up to 240° F (116° C), so I suppose my question is whether or not temperatures near the surface of engine room walls ever reach 116° C. I would test this myself, but my bus is currently cribbed and unable to run.

Thank you for any help.

[family wagon]

I can't speak to temperatures in the bay, but I'd suggest verifying that the foam is compatible with oil, grease, fuel, solvents, etc. Maybe ask about its fire retardant qualities too (if any).

[BlackJohn]

A guy needs hand room to work on these beasts. I wouldn't take that away.
Parts need room to get into place without more difficulties.
How will that affect pulling the whole engine out if need be?
It might reduce noise in selected areas but those engines need air circulating in that compartment or you risk damage that way.
Not in favour of insulating that way.


John,

[magnakansas]

Thinking from a fire point of view, the foam is probably toxic in a flame. I would use rockwool

https://www.google.com/search?q=how+...TF-8#kpvalbx=1

instead. You keep it in place with something like a hardware cloth cover/cage. areas near the exhaust/turbo can go over 240 degrees. Paper auto ignites at 450 degrees.

think i will use this stuff in an attempt to quiet my bus.

william

[Marceps]

Good points all around. Where fire is concerned, however, Tiger Foam's “fast rise” insulation is Class 1 fire retardant. So I'm mostly worried about whether or not the engine bay's temperatures reach a level that will damage the foam.

Where engine service is concerned, the engine bay roof (insulated) will pop off. The insulation could also be destroyed, if need be.

think i will use this stuff in an attempt to quiet my bus.

You may want to consider ceramic batt insulation instead.

[Tango]

Rockwool holds water like a sponge.

[joeblack5]

Personally i would not attempt that in the engine bay. That stuff is pretty flammable. Having had myself small leaks from coolant, diesel and oil it seems a bad idea to combine all these factors. I have not measured it but I would imagine that with a stop after a long run with a hot turbo and no air cooling the temps above the exhaust header and turbo would easily exceed that.



In our E350 diesel the sound and heat insulation is pressed fibre with an aluminum foil topcoat.



Later J

[Tango]

If there is a turbo in there, you'll be looking at pipe temps that will easily melt lead on the pipe. From 500 to 1000 degrees at times.