Vehiclular fires and rum.

FriendlyFire · Posted: Sat Nov 07, 2009 12:06 am Post subject: Vehiclular fires and rum.

There were two fatal accidents recently where the victims were burnt (in the case of the truck it should be noted that diesel has a relatively high ignition tempreture).

Is it possible that a bottle of alcohol could have been the fuel source? (Don't bother to look for too much evidence of this after the fire though)

Just wondering.

st7 · Joined: 23 Oct 2006 Tech posts: 0 My 2NRide:

i hope u din join tuner to ask that FriendlyFire, Confused

nareshseep · Posted: Sat Nov 07, 2009 12:23 am Post subject:

wham now st7

Hook · Posted: Sat Nov 07, 2009 12:24 am Post subject:

Up to this week I was wondering this, but not along the lines of alcohol being an accelerant.

If u look at the cases thus far, these are all older vehicles (in the most recent case, it was a trunk, but we can guess from history how maintenance schedules for these can be). Over the years I've seen many threads on Tech Stuff on vacuum leaks and old/cracked vacuum lines in the engine bay etc. and at times I wondered about the condition of rubber fuel lines in these same cars, if something as simple as an aged vacuum line can be an issue.

Routinely I check my hoses for cracks/softness etc., because I've mostly only ever had older vehicles at home here. But how many of us do that?
I'm thinking that it's possible that an old worn line may have ruptured in the engine bay on impact, fueling these infernos we keep reading about in these collisions.

What y'all think?

buzz · Posted: Sat Nov 07, 2009 12:40 am Post subject:

its a good theory

i too was saying "diesel explode?" wtf Confused

Firewall · Posted: Sat Nov 07, 2009 12:55 am Post subject:

Hook, true, but to get an explosion is fairly difficult. most expected is a fire.

also it don't really matter alone about the lines, because gas in the engine, when that crumples sparks galore and it is ignited, not sure if positive pressure going to keep the flames from reaching the tank, even if it does plastics and fabric already ignite.

what you describing there don't even need an accident to cause serious trouble.

BTW.........................eh heh?

contents:

FriendlyFire · Posted: Sat Nov 07, 2009 1:12 am Post subject:

buzz · Posted: Sat Nov 07, 2009 1:14 am Post subject:

^^^

slow323 · Posted: Sat Nov 07, 2009 2:42 am Post subject:

if diesel was to fall on a hot part of the car and start to give off vapor after and accident wouldnt a spark ignite that as a possible cause

FriendlyFire · Posted: Sat Nov 07, 2009 7:17 am Post subject:

Gasoline falling on a hot part of a car is a likely source of a vehicular fire following an accident. That is because of it's relatively low ignition temperature when compared to fuels like diesel and kerosene.

Diesel would have required extremely high temperatures to ignite and when you consider that diesel engines don't use spark plugs but the pressure from compression for ignition, you have to consider other possibilities beyond diesel on hot engine parts.

hydroep · Posted: Sat Nov 07, 2009 8:12 am Post subject:

According to this Wiki article diesel actually has a lower autoignition temperature* (210 °C) than gasoline (246 °C).

So it's also possible that the diesel could have been ignited by leaking onto something hot like the exhaust.

*The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark.

TK! · Posted: Sat Nov 07, 2009 8:17 am Post subject:

ok mythbusters ... test ... i gone buy some diesel...

Hook · Posted: Sat Nov 07, 2009 8:18 am Post subject:

megadoc1 · Posted: Sat Nov 07, 2009 8:26 am Post subject:

diesel spilled onto a very hot manifold will ignite without a spark
but gasoline will not
gasoline is treated to withstand high temperatures the higher the ron rating the higher
the the resistance to heat

but diesel will vaporize and boom

megadoc1 · Posted: Sat Nov 07, 2009 8:40 am Post subject:

FriendlyFire · Posted: Sat Nov 07, 2009 8:41 am Post subject:

Hydroep - If you double check the wiki article you referred to you would see that there is a difference between the autoignition temperature and the flashpoint. The higher auto ignition temperature of diesel is used to provide safe igintion in the engine but for gasoline it's the lower flash point that is important.

I was particularly making referrence to diesel's higher flash point when compared to gasoline and not it's autoignition temperature.

Megadoc - That is to be expected because the red hot metal would quickly get the diesel up to it's autoignition temperature so no ignition source was required.

My question with respect to the truck accident has to do with the fact that the possibility of metal from that truck remaining red hot long enough for the diesel to reach it's auto ignition temperature seems remote.

nareshseep · Posted: Sat Nov 07, 2009 8:47 am Post subject:

^^ so super with it lower octane may be a culprit?

hydroep · Posted: Sat Nov 07, 2009 8:59 am Post subject:

megadoc1 · Posted: Sat Nov 07, 2009 9:00 am Post subject:

but once the truck is running the exhaust temperature will be up
and thats enough temperature for fire
since you are on possibilities the truck could have been on fire before the crash
who knows

when i was younger i tried cleaning an oil spill on a hot manifold using diesel
it just blew , yuh see the diesel becomes a vapor first the n every thing lights up
even the smoke u see at first

btw what does cause them ptsc bus to bun down so? not alcohol

megadoc1 · Posted: Sat Nov 07, 2009 9:10 am Post subject: