I wouldn't jump to any conclusions... Some cars have fiberglass bonnets,
yes, but are they as close to the engine and manifolds as the MGB bonnet?
And are their engine compartments as restricted ventilation-wise?
I can get a fiberglass hood for my 1967 Barracuda, but there must be a foot
of air space between the cylinder heads and the underside of the hood, and
it has a full-width insulation pad. Not to mention a relatively enormous
amount of room for air circulation.
I think you would have to assume at least 200 degree temps for the underside
of the bonnet. But if it's really a concern, an empirical test is in order.
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires
on 2/19/05 1:09 PM, Barrie Robinson at barrie@look.ca wrote:
> James,
>
> No - no variables! I just want the highest temp reached, - how, when and
> if, is of no concern - just the hottest. But you have solved my problem -
> I think! Do some cars have fibre glass bonnets? If so then the bonnet
> temp must be below 150 deg F ????? The real way to find out is to tape a
> thermometer under the hood and see what it registers after a long run - and
> after standing for a few minutes! Would anyone in a warm clime like to
> perform this experiment?
>
> At 08:36 AM 2/19/2005, you wrote:
>> Barrie,
>> There are too many variables out there to come up with an answer to
>> that one. Having said that, I'd suggest that you investigate a
>> reflective surface on the engine-side of the dampening material, or a
>> combo of insulating matereal atop a deadening compound. Dynamat and
>> others do this. Let me throw out someunrelated numbers that will be of
>> absolutely no use to you: Engine exhaust manifolds can easily reach
>> ~1200 Deg F, if they are uncoated or unwrapped. Resin-based Fiberglass
>> panels will soften at ~150 Deg F. Some OEM paints blister or discolour
>> on the hoods of really hot engines. Assume a heat gun can do the same
>> thing at ~600 Deg F. Also, if the car is painted a dark color (or
>> colour) like BRG or black, the sun, itself, can heat the material to
>> nearly boiling (or higher). For this reason, many fiberglass panel/body
>> folks recommend against painting their products black.
>> JJJ
>>
>>
>> Barrie Robinson wrote:
>>
>>> Can anyone tell me with authority, the maximum temperature reached under
>>> the hood - at the hood? I need to know to check out what adhesives will
>>> stick sound deadening stuff under the bonnet (hood)
>>>
>>> Regards
>>>
>>> Barrie Robinson
>>
>> Regards
>> Barrie
>>
>> Barrie Robinson
>> (705) 721-9060
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