hood insulator?
- Thread starter jbracing
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it won't hurt your paint with no insulator....that was mainly put there to deaden the engine noise...
here's a test they did sometime after 2005 of hood insulators so i think the hood insulators installed in the G bodys were not part of the 5 of the 20 of insulators they found to be fire retardant...I think the ones on our cars would fit into the category of contributing to the fire..
Twenty vehicles were selected for further testing of the fire properties of underhood materials in
the fleet. The 20 vehicles represented a convenience sample of various manufacturers and classes
of SUVs, passenger cars, minivans and pickup trucks. Coupons cut from the insulating liners
were tested to assess their fire retarding properties with a cone calorimeter according to the test
procedures of ASTM E 1354-03. The mounting hardware used to affix the liners to the under
side of the hood was also tested to determine if their materials would melt or distort sufficiently
to allow the insulating materials to fall.
The cone calorimeter test subjected a 10 cm x 10 cm material coupon to a constant radiant heat
flux of 35 kW/m2 for 20 minutes. From the materials behavior under the heat load the
ignitability, heat release rates, mass loss rates, effective heat of combustion and visible smoke
development of materials were determined and documented. Of the 20 insulating underhood
liners tested, 5 did not ignite. An additional 7 insulation samples that did ignite exhibited a short
Page 6 of 7
time to flameout with comparatively low peak heat release rates. These samples with the
inclusion of the non igniting samples show the most potential for retarding an engine fire. There
was a wide range of weight loss and heat release rates among the group of samples tested.
Several of the insulation materials would have contributed fuel to an underhood fire rather than
acting to retard it.
The cone calorimeter testing indicated that the application of a metal foil to the engine facing side
of an underhood insulting liner can significantly enhance the fire resistance of an insulating
material by preventing ignition.
If an underhood insulation liner is to smother a fire the mounting clips affixing it to the hood
must disengage from the hood under high heat conditions of an engine compartment fire. The
mounting clips for the underhood insulation from the twenty different vehicles tested disengage
from the supporting structure at temperatures ranging from 133 °C to 268 °C. The results seemed
to indicate that the design of the mounting clips may have an influence on the deformation pattern
and the temperature required for the insulating sample to disengage.
Given that fire resistant underhood insulating liners were identified amongst the small sample of
vehicles examined, the possibility of the liners acting to retard engine compartment fire is
plausible . However, the effectiveness of such a system can not be determined strictly from the
component tests that were performed. Several of the underhood insulation materials in current
use would contribute fuel to an underhood fire.
Twenty vehicles were selected for further testing of the fire properties of underhood materials in
the fleet. The 20 vehicles represented a convenience sample of various manufacturers and classes
of SUVs, passenger cars, minivans and pickup trucks. Coupons cut from the insulating liners
were tested to assess their fire retarding properties with a cone calorimeter according to the test
procedures of ASTM E 1354-03. The mounting hardware used to affix the liners to the under
side of the hood was also tested to determine if their materials would melt or distort sufficiently
to allow the insulating materials to fall.
The cone calorimeter test subjected a 10 cm x 10 cm material coupon to a constant radiant heat
flux of 35 kW/m2 for 20 minutes. From the materials behavior under the heat load the
ignitability, heat release rates, mass loss rates, effective heat of combustion and visible smoke
development of materials were determined and documented. Of the 20 insulating underhood
liners tested, 5 did not ignite. An additional 7 insulation samples that did ignite exhibited a short
Page 6 of 7
time to flameout with comparatively low peak heat release rates. These samples with the
inclusion of the non igniting samples show the most potential for retarding an engine fire. There
was a wide range of weight loss and heat release rates among the group of samples tested.
Several of the insulation materials would have contributed fuel to an underhood fire rather than
acting to retard it.
The cone calorimeter testing indicated that the application of a metal foil to the engine facing side
of an underhood insulting liner can significantly enhance the fire resistance of an insulating
material by preventing ignition.
If an underhood insulation liner is to smother a fire the mounting clips affixing it to the hood
must disengage from the hood under high heat conditions of an engine compartment fire. The
mounting clips for the underhood insulation from the twenty different vehicles tested disengage
from the supporting structure at temperatures ranging from 133 °C to 268 °C. The results seemed
to indicate that the design of the mounting clips may have an influence on the deformation pattern
and the temperature required for the insulating sample to disengage.
Given that fire resistant underhood insulating liners were identified amongst the small sample of
vehicles examined, the possibility of the liners acting to retard engine compartment fire is
plausible . However, the effectiveness of such a system can not be determined strictly from the
component tests that were performed. Several of the underhood insulation materials in current
use would contribute fuel to an underhood fire.
There were no factory cowls so you have to make one . Gm discontinued according to 3 GM dealers these so an after market one is all to be found and they r flat not formed .
Definitely won't hurt the paint - I never installed one after it was painted for the shaker and even the paint on the underside looks new. Remember most cars never came with one from the factory.
I'm sure it was almost strictly for sound deadening, and even if it was intended as a fire retardant - years of oil would negate that in a hurry! LOL
I'm sure it was almost strictly for sound deadening, and even if it was intended as a fire retardant - years of oil would negate that in a hurry! LOL
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