Engine Fire Extinguishers

Point taken Emery. My concern is with the amount of heat generated in the
compartment after a long drive. All that hot steel in there has to have a lot of
heat to get rid of. The point is, don't get to low a temp. sprinkler for any
extinguisher system you install. Darren

> - if you do some measurement of the temp in the engine compartment
> after the engine is shut down you should add about 50 degrees to it to take
> care of the ambient temperature that one might encounter such as in the
> Mohave desert as some of us travel to some God awful hot places in the
> summer. Maybe you should just run over to Death Valley in August and do your
> measurement then.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM

- --

Darren Paget
76 Experimental
Another Fab Day
http://www.TZEplus.com
 
Darren, I have been operationg for about three or four years now with an
automaticly activated fire extinguisher made by Hawk, who by the way as I am
told is no longer in business, that supposedly has aa discharge temp of 200 deg
f. I can tell you that I have definetely had my coach well heated up in that
time, including running hard in great heat and then stopping at a rest area and
shutting it off. Granted, the discharge temp could be different than advertised,
but it seems like a pretty well put together unit. My point is that my temp in
my engine compartment probably been at least as high as most under normal
circumstances, and no discharge. Conclusion: 200 degrees is probably not too low
a discharge temp for an automatically operated fire extinguishing system.
Simply my thoughts and works for me.
Pat 77 Birch

> Don't forget. After driving all day in the hot sun and then stopping, the
> ambient air temp. in the compartment will climb well above 225 - 275. All
> the latent heat in the engine will still be a factor when stopped, without
> the fan running. Darren
>

>
> > Emery,
> >
> > I agree that the engine surface temps will get way above 212degF, but the
> > ambient air temp won't. Just think, would a cup of water suspended above
> > the engine boil? I doubt it.
> >
> > The concern is the abient air temp., not the engine surface temp. as the
> > fusible links would be suspend from a cable above the engine.
> >
> > Patrick
> >

> > >
> > > In a message dated 1/19/00 6:57:59 AM,
> > > Patrick.Flowers

> > >
> > > > >
> > > fine - much higher and it would delay activation too long.
> > >
> > > >>
> > >
> > > Patrick - It would be interesting if someone has any data on
> > > the temperatures
> > > that can exist in the engine box. I would guess that it gets
> > > a lot higher
> > > than 212 deg. on a hot day. The water temperature in the
> > > block is often up
> > > to as much as 250 deg. and the exhaust manifolds and pipes
> > > are way hotter.
> > > The intake manifold on mine has charred paint where the
> > > crossover by the carb
> > > mount is.
> > >
> > > Emery Stora
> > > 77 Kingsley
> > > Santa Fe, NM
> > >
>
> --
>
> Darren Paget
> 76 Experimental
> Another Fab Day
> http://www.TZEplus.com
 
It's important not to err too far on either side. The correct actuation
temperature is a balance between false activation and preventing
structural involvement. Too low and the system will operate prematurely
- - too high and the fire has a chance to spread to the structure(whether
it be a building or motorhome) before the system operates.

Patrick

>
> The point is, don't get to low a temp. sprinkler for any
> extinguisher system you install.
- --
Patrick Flowers
Mailto:patrick

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
Today, 10/19/00, Pat Moore said:

" Darren, I have been operationg for about three or four years now with an
automaticly activated fire extinguisher made by Hawk, who by the way as I am
told is no longer in business, that supposedly has aa discharge temp of 200 deg
f. I can tell you that I have definetely had my coach well heated up in
that time, including running hard in great heat and then stopping at a rest
area and
shutting it off. Granted, the discharge temp could be different than
advertised,
but it seems like a pretty well put together unit. My point is that my temp in
my engine compartment probably been at least as high as most under normal
circumstances, and no discharge. Conclusion: 200 degrees is probably not
too low a discharge temp for an automatically operated fire extinguishing
system.
Simply my thoughts and works for me."

Pat; Can't imagine temp. under 200 when shut down after hard pull. Are you
sure it's working at all? We seem to add things and hope they will work
when we need them. When they don't, they're out of warranty and we're out
in the boondocks needing it to work. Can you test the system w/o a full
discharge?

Best to know it works before you need it.

Dave (& Dege), '76 Royale, Santa Barbara, CA
 
Norm Karsch sold those but later he found out he could not get any more. Thus he
stopped selling them.
al

> Gentlemen, a few years back at one of the international rallies, I bought a
> fire extinguisher for the engine compartment that is automatically discharged
> when the air temp reaches 200 degrees f. It also has a warning light that lights
> when the extinguisher is activated. The name on it is"Hawk Fire System" mod-A10.
> It is a one pound liquid gas type extinguisher. Made by Hawk International Inc.
> 10421 Burnham Dr. NW #3 Gig Harbor, Wa 98335. 206 851 3444. I can't remember who
> I bought it from but it was one of the venders at the rally.
> Don't know if it is still abvailable or not, but that is the information that I
> have. Supposed to discharge 50 cubic feet of extinguishing agent. Theoretically
> will extinguish an engine fire long enough to stop the coach and open the hatch.
> Hope I never have to find out if it is effective
> Pat 77 Birch

>

> >
> > >
> > Justin's articles are posted at:
> > http://www.gmcclassics.com/tech/technical.html
> >
> > Sometimes I just need a little 'kick start". :-)
> >
> > bdub >>
> >
> > Justin - have you given any thought to having an automatic system using a
> > temperature sensitive link that would melt and somehow release the lever on
> > the extinguisher? There are times where someone could have a fire and not
> > realize it until it is too late. Perhaps the pressure could also be to the
> > heads at all times and one could use heads that opens with high temperature
> > similar to a building head.
> >
> > Anyone else have info on this?
> >
> > Emery Stora
> > 77 Kingsley
> > Santa Fe, NM
 
Now waiddaminit! I don't mind you disagreeing with me(happens all the
time), but be sure you know what you're disagreeing with. What I said
was that dry chem was a better choice than gas as an extinguishant in this
application. The extinguishant gases will dissipate while the dry chem will
adhere to wet surfaces(note in the engine compartment that the only "wet"
surfaces will probably be either oil or fuel). This doesn't take cleanup
into consideration - in our business, cleanup is a given. We wouldn't
recommend dry chemical where it might cause secondary damage(i.e. computer
equipment or clean rooms), but otherwise we know we're gonna' have to pay
for cleanup and dry chem doesn't make that any worse.

Also note that dry chem operates on the same principle as Halon - it
interferes chemically with the combustion reaction. CO2 works principally
by exclusion of oxygen along with some cooling effect. It requires
concentrations of 60-70% to be effective. Halon requires only 10-15%
concentrations, but doesn't have the cooling effect.

I have no doubt that CO2 can be effective in this application, but IMO dry
chemical would do a better job.

Disclaimer, these opinions are my own and are not those of my employer nor
its parent companies,
Patrick

> I want to disagree with you on the gas (co2) not being
> satisfactory because of wind turbulence.
 
Lanier,

You've lost me - what liquid?

Patrick

>
> My concern is: what about the mess caused by pouring liquid
> on an extremely hot engine - can you imagine the damage??
 
Dave, I agree that it would be very nice to know for sure iof the extinguisher
for sure works or not, but the only way that I am aware of to find out is to put a
flame beside the thermal link and discharge it. That, I think would be very counter
productive as then I also wouldn' have an engine extinguisher. I think that there
are many things that we take on faith in many areas of our lives. I don't see any
way for us to be sure about a lot of things, We just must do the best we can with
what we have. If I have a fire and the extinguisher doesn't work, then I guess I
will go to plan two which would have been plan one if I hadn't had the
extinguisher. But I appreciate the concern.
Pat 77 Birch

> Today, 10/19/00, Pat Moore said:
>
> " Darren, I have been operationg for about three or four years now with an
> automaticly activated fire extinguisher made by Hawk, who by the way as I am
> told is no longer in business, that supposedly has aa discharge temp of 200 deg
> f. I can tell you that I have definetely had my coach well heated up in
> that time, including running hard in great heat and then stopping at a rest
> area and
> shutting it off. Granted, the discharge temp could be different than
> advertised,
> but it seems like a pretty well put together unit. My point is that my temp in
> my engine compartment probably been at least as high as most under normal
> circumstances, and no discharge. Conclusion: 200 degrees is probably not
> too low a discharge temp for an automatically operated fire extinguishing
> system.
> Simply my thoughts and works for me."
>
> Pat; Can't imagine temp. under 200 when shut down after hard pull. Are you
> sure it's working at all? We seem to add things and hope they will work
> when we need them. When they don't, they're out of warranty and we're out
> in the boondocks needing it to work. Can you test the system w/o a full
> discharge?
>
> Best to know it works before you need it.
>
> Dave (& Dege), '76 Royale, Santa Barbara, CA
 
IIRC, there have been several testimonials in GMCMM for the Hawk
extinguishers, so their performance should not be an issue. I'm certain it
used a UL listed release device(a fusible link), so it's reliability is
assured by independent testing. There was also a letter from the
manufacturer in GMCMM explaining that they would no longer manufacture them
due to the CFC ban. Halons are chlorofluorcarbons and they are no longer
manufactured. There is some stock on hand, but by law, it can only be used
to refill pre-existing units. No new devices using CFCs can be
manufactured.

You are correct that there is no more factory support for this unit, but it
should be fine until it discharges.

Patrick

>
> Today, 10/19/00, Pat Moore said:
>
> > " Darren, I have been operationg for about three or four
> > years now with an automaticly activated fire extinguisher
> > made by Hawk, who by the way as I am told is no longer in
> > business, that supposedly has a discharge temp of 200 deg
> > f. I can tell you that I have definetely had my coach well
> > heated up in that time, including running hard in great
> > heat and then stopping at a rest area and shutting it off.
> > Granted, the discharge temp could be different than
> > advertised, but it seems like a pretty well put together
> > unit. My point is that my temp in my engine compartment
> > probably been at least as high as most under normal
> > circumstances, and no discharge. Conclusion: 200 degrees
> > is probably not too low a discharge temp for an
> > automatically operated fire extinguishing system.
> > Simply my thoughts and works for me."
>
> Pat; Can't imagine temp. under 200 when shut down after hard
> pull. Are you sure it's working at all? We seem to add
> things and hope they will work when we need them. When they
> don't, they're out of warranty and we're out in the
> boondocks needing it to work. Can you test the system w/o
> a full discharge?
>
> Dave
>
>
 
Can we design a system that has an automatic AND a manual discharge?
Just a thought.

Peter
77 Eleganza II
Colorado

- ----- Original Message -----
From:
To:
Sent: Thursday, January 20, 2000 6:45 AM
Subject: Re: GMC: Engine Fire Extinguishers

> Dave, I agree that it would be very nice to know for sure iof the
extinguisher
> for sure works or not, but the only way that I am aware of to find out is
to put a
> flame beside the thermal link and discharge it. That, I think would be
very counter
> productive as then I also wouldn' have an engine extinguisher. I think
that there
> are many things that we take on faith in many areas of our lives. I don't
see any
> way for us to be sure about a lot of things, We just must do the best we
can with
> what we have. If I have a fire and the extinguisher doesn't work, then I
guess I
> will go to plan two which would have been plan one if I hadn't had the
> extinguisher. But I appreciate the concern.
> Pat 77 Birch
>

>
> > Today, 10/19/00, Pat Moore said:
> >
> > " Darren, I have been operationg for about three or four years now with
an
> > automaticly activated fire extinguisher made by Hawk, who by the way as
I am
> > told is no longer in business, that supposedly has aa discharge temp of
200 deg
> > f. I can tell you that I have definetely had my coach well heated up in
> > that time, including running hard in great heat and then stopping at a
rest
> > area and
> > shutting it off. Granted, the discharge temp could be different than
> > advertised,
> > but it seems like a pretty well put together unit. My point is that my
temp in
> > my engine compartment probably been at least as high as most under
normal
> > circumstances, and no discharge. Conclusion: 200 degrees is probably not
> > too low a discharge temp for an automatically operated fire
extinguishing
> > system.
> > Simply my thoughts and works for me."
> >
> > Pat; Can't imagine temp. under 200 when shut down after hard pull. Are
you
> > sure it's working at all? We seem to add things and hope they will work
> > when we need them. When they don't, they're out of warranty and we're
out
> > in the boondocks needing it to work. Can you test the system w/o a full
> > discharge?
> >
> > Best to know it works before you need it.
> >
> > Dave (& Dege), '76 Royale, Santa Barbara, CA
>
>
 
Peter,

Pardon us for overlooking the obvious. Yes, you definitely want to be able
to discharge the system manually.

Thanks!
Patrick

>
> Can we design a system that has an automatic AND
> a manual discharge? Just a thought.