Engine Compartment Temperatures
- Thread starter the hamiltons
- Start date
Any body know the flash points of the various flammable materials in the
engine compartment? Fluids? Seems the correct point to set an automatic
extinguisher would be just above the lowest item's flash point. Does this
make any sense? Just thinking.
Roger
engine compartment? Fluids? Seems the correct point to set an automatic
extinguisher would be just above the lowest item's flash point. Does this
make any sense? Just thinking.
Roger
Thank you Al! Excellent post.
Patrick
>=20
> The discussions last winter about the excessive heat from=20
> headers caused me to check the temperatures over a month and=20
> a half last summer. I had headers on for two years at the=20
> time and had not noticed an increase in heat or anything=20
> burned around the engine. Our travels take us around southern
> Ontario and northern New York mostly. Those from the southern=20
> part of the continent experience higher temperatures than we=20
> do and it would be interesting to hear if engine compartment=20
> temperatures go up proportionately to the rise of the outside=20
> temperature. I suspect they do based on what I found.
>=20
> I used a digital thermometer with a probe. All temperatures=20
> are in Fahrenheit. The probe was secured in four locations over=20
> the time: a couple of inches above the header pipe of # 7 and=20
> #8 cylinder, behind the distributor, and behind the carburator=20
> an inch above the intake manifold crossover.
>=20
> The test days ranged from 75=B0 to 90=B0 with the higher=20
> temperature days having high humidity as well. At highway speeds=20
> the temperatures varied from 130 to 150=B0, slowing down in a town=20
> changed the range from 150 to 162=B0. After stopping the=20
> temperature rose slightly then dropped fairly quickly. If the=20
> engine was shut off coming off the highway, the temperature=20
> quickly rose to between 168 to 192=B0 and only started to fall=20
> slowly after about 15 minutes. This is when the heat transfer to=20
> the living area is greatest and I plan to put some fans on to=20
> remove the hot air after stopping. This was described in GMCMM=20
> a few years ago.
>=20
> The highest temperatures were recorded on the over 90=B0 days.=20
> Hill climbing would send the engine temperature up 15=B0 but the=20
> air surrounding the engine would only go up a few degrees.
>=20
> Al Hamilton
> 76 Eleganza II
> Kingston, Ont
=20
Patrick
>=20
> The discussions last winter about the excessive heat from=20
> headers caused me to check the temperatures over a month and=20
> a half last summer. I had headers on for two years at the=20
> time and had not noticed an increase in heat or anything=20
> burned around the engine. Our travels take us around southern
> Ontario and northern New York mostly. Those from the southern=20
> part of the continent experience higher temperatures than we=20
> do and it would be interesting to hear if engine compartment=20
> temperatures go up proportionately to the rise of the outside=20
> temperature. I suspect they do based on what I found.
>=20
> I used a digital thermometer with a probe. All temperatures=20
> are in Fahrenheit. The probe was secured in four locations over=20
> the time: a couple of inches above the header pipe of # 7 and=20
> #8 cylinder, behind the distributor, and behind the carburator=20
> an inch above the intake manifold crossover.
>=20
> The test days ranged from 75=B0 to 90=B0 with the higher=20
> temperature days having high humidity as well. At highway speeds=20
> the temperatures varied from 130 to 150=B0, slowing down in a town=20
> changed the range from 150 to 162=B0. After stopping the=20
> temperature rose slightly then dropped fairly quickly. If the=20
> engine was shut off coming off the highway, the temperature=20
> quickly rose to between 168 to 192=B0 and only started to fall=20
> slowly after about 15 minutes. This is when the heat transfer to=20
> the living area is greatest and I plan to put some fans on to=20
> remove the hot air after stopping. This was described in GMCMM=20
> a few years ago.
>=20
> The highest temperatures were recorded on the over 90=B0 days.=20
> Hill climbing would send the engine temperature up 15=B0 but the=20
> air surrounding the engine would only go up a few degrees.
>=20
> Al Hamilton
> 76 Eleganza II
> Kingston, Ont
=20
Roger,
Nope, it won't work. The flash point of gasoline is hard to pin down
because it's a mixture of chemicals, but it's probably down around 30degF.
You want to base the release temperature on ambient. AAMOF, NFPA 13, the
standard for installation of automatic sprinkler systems, has a selection
chart for sprinkler heads which is based on maximum ambient ceiling
temperature. It's assumed that when "normal" ambient temperature is
exceeded by a given amount, there's an abnormal condition requiring system
activation.
You may be confusing "flash point" with "autoignition temperature". Flash
point is the temperature at which a liquid will evolve sufficient vapors to
support combustion. Autoignition temperature is the point at which the
substance will spontaneously ignite.
BTW, I erred earlier when I said that CO2 required concentrations from
60-70%. The actual range is 34-77% depending upon the substance involved.
For gasoline fires, the minimum design concentration is 35%, but keep in
mind this is for a closed environment(total flooding).
Patrick
>
> Any body know the flash points of the various flammable
> materials in the engine compartment? Fluids? Seems
> the correct point to set an automatic extinguisher would
> be just above the lowest item's flash point. Does this
> make any sense? Just thinking.
>
> Roger
>
Nope, it won't work. The flash point of gasoline is hard to pin down
because it's a mixture of chemicals, but it's probably down around 30degF.
You want to base the release temperature on ambient. AAMOF, NFPA 13, the
standard for installation of automatic sprinkler systems, has a selection
chart for sprinkler heads which is based on maximum ambient ceiling
temperature. It's assumed that when "normal" ambient temperature is
exceeded by a given amount, there's an abnormal condition requiring system
activation.
You may be confusing "flash point" with "autoignition temperature". Flash
point is the temperature at which a liquid will evolve sufficient vapors to
support combustion. Autoignition temperature is the point at which the
substance will spontaneously ignite.
BTW, I erred earlier when I said that CO2 required concentrations from
60-70%. The actual range is 34-77% depending upon the substance involved.
For gasoline fires, the minimum design concentration is 35%, but keep in
mind this is for a closed environment(total flooding).
Patrick
>
> Any body know the flash points of the various flammable
> materials in the engine compartment? Fluids? Seems
> the correct point to set an automatic extinguisher would
> be just above the lowest item's flash point. Does this
> make any sense? Just thinking.
>
> Roger
>
Now if we could also get readings from regular exhaust manifolds, thorley
uncoated headers, Thorley headers using Jet hot and Thorley headers coated
with Swain white lightening we would have information to based a sound
decision on.
I will install my Thorley headers with White Lightening in the spring so
will provide that data.
> The discussions last winter about the excessive heat from headers=
caused
>me to check the temperatures over a month and a half last summer. I had
>headers on for two years at the time and had not noticed an increase in=
heat
>or anything burned around the engine. Our travels take us around southern
>Ontario and northern New York mostly. Those from the southern part of the
>continent experience higher temperatures than we do and it would be
>interesting to hear if engine compartment temperatures go up=
proportionately
>to the rise of the outside temperature. I suspect they do based on what I
>found.
>
> I used a digital thermometer with a probe. All temperatures are in
>Fahrenheit. The probe was secured in four locations over the time: a couple
>of inches above the header pipe of # 7 and #8 cylinder, behind the
>distributor, and behind the carburator an inch above the intake manifold
>crossover.
>
> The test days ranged from 75=B0 to 90=B0 with the higher temperature=
days
>having high humidity as well. At highway speeds the temperatures varied
>from 130 to 150=B0, slowing down in a town changed the range from 150 to=
162=B0.
>After stopping the temperature rose slightly then dropped fairly quickly.=
If
>the engine was shut off coming off the highway, the temperature quickly=
rose
>to between 168 to 192=B0 and only started to fall slowly after about 15
>minutes. This is when the heat transfer to the living area is greatest and=
I
>plan to put some fans on to remove the hot air after stopping. This was
>described in GMCMM a few years ago.
>
> The highest temperatures were recorded on the over 90=B0 days. Hill
>climbing would send the engine temperature up 15=B0 but the air surrounding
>the engine would only go up a few degrees.
>
>
>
>Al Hamilton
>76 Eleganza II
>Kingston, Ont
>
>
>
uncoated headers, Thorley headers using Jet hot and Thorley headers coated
with Swain white lightening we would have information to based a sound
decision on.
I will install my Thorley headers with White Lightening in the spring so
will provide that data.
> The discussions last winter about the excessive heat from headers=
caused
>me to check the temperatures over a month and a half last summer. I had
>headers on for two years at the time and had not noticed an increase in=
heat
>or anything burned around the engine. Our travels take us around southern
>Ontario and northern New York mostly. Those from the southern part of the
>continent experience higher temperatures than we do and it would be
>interesting to hear if engine compartment temperatures go up=
proportionately
>to the rise of the outside temperature. I suspect they do based on what I
>found.
>
> I used a digital thermometer with a probe. All temperatures are in
>Fahrenheit. The probe was secured in four locations over the time: a couple
>of inches above the header pipe of # 7 and #8 cylinder, behind the
>distributor, and behind the carburator an inch above the intake manifold
>crossover.
>
> The test days ranged from 75=B0 to 90=B0 with the higher temperature=
days
>having high humidity as well. At highway speeds the temperatures varied
>from 130 to 150=B0, slowing down in a town changed the range from 150 to=
162=B0.
>After stopping the temperature rose slightly then dropped fairly quickly.=
If
>the engine was shut off coming off the highway, the temperature quickly=
rose
>to between 168 to 192=B0 and only started to fall slowly after about 15
>minutes. This is when the heat transfer to the living area is greatest and=
I
>plan to put some fans on to remove the hot air after stopping. This was
>described in GMCMM a few years ago.
>
> The highest temperatures were recorded on the over 90=B0 days. Hill
>climbing would send the engine temperature up 15=B0 but the air surrounding
>the engine would only go up a few degrees.
>
>
>
>Al Hamilton
>76 Eleganza II
>Kingston, Ont
>
>
>
>Now if we could also get readings from regular exhaust manifolds, thorley
>uncoated headers, Thorley headers using Jet hot and Thorley headers coated
>with Swain white lightening we would have information to based a sound
>decision on.
>I will install my Thorley headers with White Lightening in the spring so
>will provide that data.
Remember we will need 30 data points. what I can't remember is if it should be
30 temperature readings from one set of headers or one reading off 30 sets
of headers ;-)
Jim
'73 Canyon Lands
Aurora, CO & Havre, MT
>uncoated headers, Thorley headers using Jet hot and Thorley headers coated
>with Swain white lightening we would have information to based a sound
>decision on.
>I will install my Thorley headers with White Lightening in the spring so
>will provide that data.
Remember we will need 30 data points. what I can't remember is if it should be
30 temperature readings from one set of headers or one reading off 30 sets
of headers ;-)
Jim
'73 Canyon Lands
Aurora, CO & Havre, MT
Emery,
I have a small set of vents and they help a lot, I think. I used a set of
the Volvo grills suggested by someone about six years ago in GMCMM or the
GMCMI Newsletter. I saw someone using 1950's Buick fender vents and wished
I'd waited until I could find some of those.
The heat coming out of them at idle is quite high. I've had trouble
checking them while moving though!
Sorry about that. It may be that
cabin fever is starting already.
Al Hamilton
I have a small set of vents and they help a lot, I think. I used a set of
the Volvo grills suggested by someone about six years ago in GMCMM or the
GMCMI Newsletter. I saw someone using 1950's Buick fender vents and wished
I'd waited until I could find some of those.
The heat coming out of them at idle is quite high. I've had trouble
checking them while moving though!
Sorry about that. It may be thatcabin fever is starting already.
Al Hamilton
I remember and it will be interesting when I get mine installed what the
difference will be if any.
Whats your opinion of them so far?
>Tom,
>
> You may recall, my headers are Thorley uncoated.
>
>
> Al Hamilton
>
>
>
difference will be if any.
Whats your opinion of them so far?
>Tom,
>
> You may recall, my headers are Thorley uncoated.
>
>
> Al Hamilton
>
>
>
