Daniel5691

Following Al's story today of yet another 928 fire, I wonder as a n00b if I have any true understanding of the issues leading to engine bay fires in the 928.

Fuel lines. Greg Brown. Check. Inspected regularly. Check.
Power Steering lines. Check. Regular inspection. Check.
Fire extinguisher. Check.

But now I look at 3 recent fires described here by members, etc, and I wonder if I really understand the dynamics of an engine bay fire....

Also, I find that there are "AUTOMATIC FIRE SUPPRESSION SYSTEMS" available from various "racing" vendors for around $500....

Anyway, game on, I would very much benefit from the wisdom and advice of those wiser and more knowledgeable than myself.

Thanks, guys.

jeff spahn

I have a 2.5# halon extinguisher on the passenger seat rails on a quick release. There are nozzles you can put in your engine bay for Halon that just have a ring you pull and it puts out the fire. Don't use a normal white powder extinguisher.

Daniel5691

Jeff,

Like this ? (Pegasus Racing website...)

5lb Halon Automatic/Manual Fire Suppression System

Brand: FireBottle Fire Systems

The new Automatic / Manual FireBottle brand fire suppression systems can be activated manually by a bottle-mounted pushbutton or remote pull cable, or automatically with the help of a 155 degree thermal head. When the temperature in the cockpit exceeds 155°F the system automatically triggers, dispensing all 5 pounds of Halon 1211.

Kit contains a charged aluminum cylinder measuring 14.75" long by 4" diameter, one pull cable, mounting bracket and 5 foot flame-resistant, flexible, stainless steel reinforced line with a 155°F thermal head. Includes 2 discharge nozzles,T-fitting, and 8 feet of aluminum tubing. Weighs approximately 10 lbs.

Note 1: (H) = Hazardous. All pressurized fire suppression systems are considered Hazardous by UPS and other shippers. A hazardous shipping charge of $28.50 (ground shipping) or $40.00 (air shipping) will apply.

Note 2: Halon is no longer SFI-approved. This system is only SCCA-legal in cars registered prior to 01/01/2009.

M. Requin

I think this thread is a pretty good idea. There is a lot of good stuff here, mostly contained in discussions of fires, or fire-fighting approaches, but it would be good to have a one-touch connection to all that info.

I can think of some things that would help this thread be useful:

• when reference is made to old info contained in another thread/post, the link(s) should be included;
  
• please put photographs on the RL server! lost photo links are a PIA;
  
• let's not let this turn into a discussion of which fuel line solution is the best, unless it is DIRECTLY connected with an engine fire, i.e. "I installed such and such and my car burnt up." We (should) all know this is one of the highest priorities in fire prevention, and which approach to take has been already discussed in many other threads. General experiences (I took my engine apart and all I have to show for the old fuel lines are these gnarly bits...) would be good contributions.

Cross links to and from the New Visitor thread might also be useful, but I am not sure what the protocol is for such.

I'm down to my last kopek, but that might be all these suggestions are worth...

I look forward to more discussion of this survival-level topic.

Rob Edwards

928 Classics has an excellent street car application:

http://928classics.com/fire-extinguisher-bracket.html


And Alan's solution is pretty outstanding: (See posts 23 and later)

https://rennlist.com/forums/928-foru...on-system.html




Here's what I have in the GTS:




And in the Zombie:

jwyatt8171

I have followed some of Alan's threads, I think he has an suppression system? He has a web page l........ Looking.....
Fire suppression
http://www.moore-fun.net/Porsche/fir...ion_system.htm

Fire detection
http://www.moore-fun.net/Porsche/eng..._detection.htm

I hope Alan does not mind me sharing.

Cosmo Kramer

The 928 engine bay, due to its enclosed design is not forgiving at all to a fuel leak especially on a warm day. Couple that with many cars with older leaky ignition wires and you have the recipe for an engine fire. Mine was caused by one of the injector retainer clips being installed upside down, the injector worked it's was down into the intake and popped out of the fuel rail spraying high pressure fuel in the engine bay on a hot day with old ignition wires.

To mitigate this from happening, all original fuel lines need to be replaced, as well as the injector seals. New ignition wires. Any leaks in the power steering need to be fixed too as the atf is flammable.

ltoolio

Good thread, Dan.

Every time I see a fire thread, after I am relieved to see that the owner was OK, is to wonder if I've done something to the car that is going to cause it to go up in fire & smoke.

One thing that I'd find helpful and that I've been causally searching for (an will do so more diligently before I finish my work) is a "before you close the hood, check here one more time" thread.

Although I have done zero work on the fuel system, I still have paranoia that I might have bumped something loose in my other work.

ltoolio

Which in part is why it's good to have a (relatively) clean engine compartment. Easier to see leaks when they first start...

Daniel5691

Cosmo,
Your comment is very insightful, but personally for me one of the reasons that I find the fire issue confusing...

The "enclosed nature" of the engine bay seems like it would allow "bomb-like" conditions to develop, yet at the same time it seems like tons of fresh O2 flowing through would only feed a smaller fire.
would it be better to have more fresh air circ across the engine bay, to prevent fume accumulation, or would it be better to starve the area of O2.... my head is spinning LOL...

JET951

All one has to do is prevent hydrocarbons , meaning Petrol ( Gas USA speak ) and Auto trans fluid ( power steer oil ) from spraying onto the engine , be it the hot exhaust manifolds or just around the plug leads

As cars get older ( decades older ) , basic preventative maintenance ( replacing fuel & oil hoses ) is extremely important , just look at the number of Ferrari & Lamborghini engine bay fires over the last decade alone , this stuff is very common in regards to oil or fuel spraying onto very hot exhaust manifolds etc

As an example , I remember quite clearly in the late 1970's & into the 1980's here in Australia the older ( 1960's ) VW beetles/ combi's and variants were suffering engine bay fires because these older inexpensive 2nd/ 3rd hand cars were just being driven with little or no maintenance & as the engine bay fuel hoses deteriorated , engine bay fires were quite common & this is just an example( quite preventable) , I can think of at least three or four other car makes ( in the same era) with engine bay fires as these cars became very cheap to buy 2nd or 3rd hand because in this case the cars were ( at that time ) to cheap to worry about most maintenance items

The only other item we have seen ( 928 specific ) is the 12v engine harness( starter / Alt harness) deteriorating & shorting against an earth , have only seen one of these and it mainly just caused a lot of smoke until the owner realised is was a burnt wiring insulation smell & disconnected the battery

Ever since we saw that one ( 928S4 ) about ten years ago , we have replaced quite a number of these 12v harnesses ( preventative maintenance )

Hilton

I focus more on prevention than mitigation.

Eliminate old rubber (cosmo nailed it above), and any time you work on the fuel system, test extensively for leaks by just pressurising the fuel system (jump the pump) before running the car.

Imo000

Those tiny little extinguishers poted here are useless in an engine fire. They look cool bolted to the front or the back of a seat but they will not put out an engine fire. Either have a nice big one or don't have any.

I don't agree with that the GB fuel lines are the only solution. Despite the predictions of FI lines with FI clamps over the factory fittings will result in an engine fire. I yet to hear a single case where this happened. Despite the fact a tone of them were sold as kits over better part of a decade, not a single reported case of a fire.

However R12a refrigerant leaking from an AC did cause at least one fire in a 928 that I remember but maybe there are more.

voskian

Jim's 928 Classics solution, and looks good also! You can never be too safe!

dr bob

Besides the leak-prevention/avoidance in the fuel system and the power steering, engine oil is the other flammable liquid in the engine bay. Those oil cooler hoses do leak, and of course they spray onto the exhaust manifolds and flash when exhaust temps are high (under load).

Considering a recent thread on IMS relays (in '89+ cars) and bypassing same, my feeble mind harkens back to more than a few threads that disussed car fires caused by overheated catalysts. On the 32V cars with two independent ignition systems, failure of either system risks passing unburned fuel through the engine and into the catalysts. The extra HC load on those causes them to heat, overheat to the point they are glowing red, and that heat soon ignites undercoating, ATF lines on auto-trans cars, and ultimately the sound deadening and upholstery inside the cabin. Many cars have been lost to this, so many early in the 32V model life that Porsche decided to add the IMS relays to stop fuel flow to cylinders when ignition failure is suspected.

Challenges to "manual" detection include the fact that the car uses only a small percentage of available power in most driving situations. The car reverts to 4-cylinder operation, but that might not be noticed more than just needing a little more pedal to maintain speed. You do notice when the smell of burning sound-deadening fills the cabin, and by then it's usually too late unles you have a BIG extinguisher and are able to cool off the catalysts below the flashpoint of the ATF being pumped onto them. Halon depends on displacing oxygen, but since it's heavier than air, especially flame-heated air, it will do little beyond delaying the fire long enough for you to get away. This is a case where a large dry-chemical extinguisher would have the advantage. Or a fire hose or serious hgh-flow garden hose to cool the cats.


Anyway, be religious about ignition maintenance, and be sensitive to performance changes as you drive. If you don't have a working IMS system, you need extra will to block the urge to "just get it home" when something happens. Probably a good idea to have the car flatbedded regardless. Dumping fuel into the cats is a recipe for a carbeque.


Workmanship on the fuel systems:

-- Put things back in correctly. Stupid stuff like a missing or upside-down injector retainer is just too easy to avoid.

-- ANY TIME that you work on the fuel system, pressurize and leak-check everything before you start the engine and while everything is still cold. Rob and I did the intake refresh on my car, and everything seemed to be fine, even after jumpering the fuel pump relay. I still worked my way around all the connections with fingers, sniffing them for any faint trace of fuel. There were only a couple tiny seepage spots, at the rear fuel pressure damper, small enough that they easily made it through our initial look-and-sniff process. Sometimes after a long work session, it's better to come back the next day for a second 'final' inspection, after your head and senses are refreshed some. There are a LOT of places and connections to leak fuel, ATF and engine oil, all of them potential fire-starters.


Several decades ago now, a neighbor came running to the garage saying there was a fire out on the street. Some guy had somehow started a fire while working on his tired Monte Carlo, and had decided to throw his on-board sleeping bag onto the fire to try and smother it, then closed the hood. I reopened the hood and pulled off the burning sleeping bag into the street, after shutting off the engine. Then grabbed a 5-gal bucket and started filling it from a neighbor's faucet outside. Man that guy could scream, saying not to use water on his fire. But it was all the grease and oil accumulation that was burning now, since the fuel supply was shut off. Five gallons of water all at once did a nice job killing the fire. Another load of water just to be sure. Much easier cleanup than it would have been after a dry chem extinguisher. Plus I had no faith in this guy's ability to pay for the extinguisher. And the bucket was really handy.


Coincidentally to this thread, my new garage cabinets are in and I'm in the process of loading them and getting out of the 'working from stacks of boxes' environment. Now that the cabinets are in, it was easy to mount a couple big extinguishers on the walls. The Cosmo Cramer adventure hastened that too. Extinguishers are too cheap at Costco to not have one or two in easy-access garage and workshop locations.