engine fire surpression.

[mick53]

I'm building a blown 292 for my 53 1/2 ton pickup. I'm thinking about a fire surpression system. What type and what chemicals of gas is the best? I just thought since I had a bomb 3 feet in front of me it might not be a bad idea. This is going to be street / strip /show / go. There is a lot of shiney under the hood so I was concerned about chemicals. I was thinking a split system engine / cab. Thank you for any input

[Overdriven]

If your ride is on fire, the finish on the shiny bits should be the last of your concerns. Your first consideration should be looking at rule books or just asking your local track what is required. A quick glance reveals some suppression systems aren’t certified for all sanctioning bodies. If your vehicle isn’t require by the rules to have one then obviously pick what you want.

There are different agents (proper term and is better than chemical) available for use in suppression systems and extinguishers. Clean agents such as FE36, Halotron, etc are the least likely to harm finishes. These clean agents are used in laboratories, computer rooms and other sensitive places. But put something close enough to a nozzle and the finish might be at risk because it is a chemical and when it evaporates it gets real cold. I mention evaporation because these agents are stored as a liquid and spray out the nozzle as a gas. These put the fire out by displacing or sucking out the oxygen in the environment the fire is in. If you have a well vented engine compartment the agent is going to be replaced by incoming air which brings in more oxygen meaning these types of agent only work when the vehicle is stopped or in better sealed spaces.

A quick look at vehicle suppression systems revealed a bunch of AFFF (Aqueous Film Forming Foam) systems. These are a foam that contains Sodium and Acids that can harm finishes depending on the finish and length of exposure. Stainless would be fine and I wouldn’t worry too much about chrome but anything aluminum probably won’t look the same by the time you get it off. But it’s a foam that forms a film on whatever it contacts separating the fuel for the fire from oxygen. This means it’s more effective in well ventilated engine compartments while the vehicle is moving since incoming air can’t push the agent out.

[Overdriven]

I didn’t look too deep at the suppression systems just a quick glance so I didn’t see any split systems. In my opinion there’s nothing wrong with running a split system or two separate systems, once for engine compartment, one for interior. The only requirement is that you be intimately familiar with the activation of each.

Just to provide some more info for those who may not know about fire extinguishers. Most fire extinguishers use a dry chemical (powder) agent. Whether it’s ABC, BC or purple K, these are all corrosive as well. Aluminum is most at risk but it can harm other metals and finishes as well. I keep CO2 and Halon fire extinguishers in my garage just for that reason.

[mick53]

Originally Posted by Overdriven

If your ride is on fire, the finish on the shiny bits should be the last of your concerns. Your first consideration should be looking at rule books or just asking your local track what is required. A quick glance reveals some suppression systems aren’t certified for all sanctioning bodies. If your vehicle isn’t require by the rules to have one then obviously pick what you want.

There are different agents (proper term and is better than chemical) available for use in suppression systems and extinguishers. Clean agents such as FE36, Halotron, etc are the least likely to harm finishes. These clean agents are used in laboratories, computer rooms and other sensitive places. But put something close enough to a nozzle and the finish might be at risk because it is a chemical and when it evaporates it gets real cold. I mention evaporation because these agents are stored as a liquid and spray out the nozzle as a gas. These put the fire out by displacing or sucking out the oxygen in the environment the fire is in. If you have a well vented engine compartment the agent is going to be replaced by incoming air which brings in more oxygen meaning these types of agent only work when the vehicle is stopped or in better sealed spaces.

A quick look at vehicle suppression systems revealed a bunch of AFFF (Aqueous Film Forming Foam) systems. These are a foam that contains Sodium and Acids that can harm finishes depending on the finish and length of exposure. Stainless would be fine and I wouldn’t worry too much about chrome but anything aluminum probably won’t look the same by the time you get it off. But it’s a foam that forms a film on whatever it contacts separating the fuel for the fire from oxygen. This means it’s more effective in well ventilated engine compartments while the vehicle is moving since incoming air can’t push the agent out.

Thanks for the input. I wont be doing any big time racing but might as well do it to specs. I like your point about being on fire. It makes sense that the foam might be better. They are not super expensive and could keep me and the whole truck from burning up. Thank you.

[mongocanfly]

id be more worried about the "bomb'' from the gas tank than the engine...as in right behind the seat!!!!!

[BR3W CITY]

Halon is the "race" option but systems are expensive and can be a pain to maintain. The big downside with all the fire suppression stuff is that the chemical is always destructive to something. Some of the film based systems can corrode aluminum if left on, and some of the powder systems will permanently embed in interior components. If you don't require a full suppression system, its not usually something being installed optionally.

I keep an extinguisher inside the driver side front bed panel, reachable within a step from the drivers seat, and accessible to a bystander if the drive is incapacitated. I'd take a look at all the different extinguisher options (ABC, Purple stuff etc) and see if there is something that checks all the boxes you need.

[Dead Parrot]

One big downside to Halon is when exposed to fire, it can break down into very dangerous products. Bromine, Chlorine and Fluorine when breathed are rarely good for lungs.

Might give a look at a hand held CO2 unit. CO2 doesn't corrode your lungs when breathed, leave a nasty power residue to clean up and is pretty high on the list for use on petroleum fires.

The powder itself isn't bad for electronics but it does attract moisture and the resultant mess is corrosive.

[mick53]

Thanks for the input. People here are so friendly. Some people on other forums are just rude. I tend to think out of the box and there is no substitute for input. It's a ways down the road until I get to that point. Plenty of time to think about it. Thanks again.

[Overdriven]

Food for thought and info dump. All fire extinguishers and fire suppression systems need to be maintained. Maintenance intervals vary between 5 and 6 years depending on extinguisher and system type. AFFF and pressurized water are the only fire extinguishers or systems that can be maintained by non professionals but I dont recommend it. Even if you have detailed instructions from the manufacturer you’re still probably better off having a professional do it, it’s probably less expensive than you think.

Halon isn’t good for humans period. It’s bad for the ozone, superheated it breaks down as mentioned and it removes oxygen so there’s the suffocation hazard. It actually can’t be manufactured anymore but it’s replacement Halotron also removes oxygen and probably has similar hazards. I have some in my garage because I got them for free, they work well, no mess and I understand the hazards. Otherwise the chemical is expensive, the machine to recover the chemical is expensive so maintenance is expensive, if it’s a system and not a fire extinguisher that just makes it more complex and even more expensive. Other clean agents like FE36 may not break down when superheated like Halon but still have suffocation hazard and are basically as expensive.

CO2. The main hazard is it comes out cold and can form instant frost on some parts of the fire extinguisher so be sure you’re holding it correctly. Unless you discharge one in a closet you’re unlikely to suffocate. Yes they are high on the list for use on petroleum fires. My issue with them is the agent comes out of the nozzle as a literal cloud. This is great for underhood fires as the cloud will move around obstacles and reach behind them unlike powder that will just bounce off the obstacle and never reach the backside of the obstacle. The downside to the cloud is that wind moves clouds, pretty easily. The CO2 cloud disperses quickly, so it can’t shoot out of the fire extinguisher as far as other agents requiring you to be closer to the fire. CO2 needs to be stored in a pressure vessel capable of withstanding 1800psi, they are much heavier than other fire extinguishers. A 5lb abc powder fire ext is common for vehicles and weighs 9lbs. A 5lb CO2 is larger in diameter, weighs a minimum of 13lb and (in my opinion) is too small unless you’re very experienced in how the CO2 will come out and how best to direct it. I’ve never seen a dedicated (not homemade) vehicle CO2 fire system unless you count boat engine rooms or vehicles over 20,000lbs. CO2 itself is cheaper than Halon or Halotron but the cost of buying and maintaining isn’t that much cheaper.

[PGSigns]

Take a look at these guys. I had one of there systems in my Camaro. It was injected on alcohol and we had 2 nozzles in the engine bay and one at my feet. It is not Halon and they are approves by all the sanctioning bodies. http://www.firebottleracing.com/
Jimmy

[mick53]

Thanks for the reply. If I am looking at this correctly the interior is automatic and the engine compartment is manual. This would mean I would need only one pull cable? I like this idea. Trying to figure this stuff out before the internet was usually just talking to salesmen. Thanks for the info.