GT40s.com
MK-I  MK-II  MK-III  MK-IV  GULF  MIRAGE  J-CAR  LOLA
GT40s.com
Home Forum Gallery Support GT40s.com  
Register FAQ Advertisers Search Today's Posts Mark Forums Read

Go Back   GT40s.com > >

GT40 Tech - Fueling, Electrics, & Engine Cooling Petrol, Electrons, & Water

Reply
 
Thread Tools Display Modes
Old 19th December 2017, 08:53 AM   #1
Nick Brough's Avatar
Nick Brough
Bronze Supporter
United Kingdom
 
Join Date: Apr 2006
Location: Warrington UK
GT40: SGT 351W G50
Posts: 1,761
Weber ida fire extinguisher nozzle positions

Just wondering where the best position to place my fire extinguisher nozzles in the engine bay. Not sure where the most likely place for fires to start, was thinking pointing them at the 4 gauze's between the carbs, would this be correct.
__________________
Regards
Nick
Nick Brough is offline   Reply With Quote
Old 19th December 2017, 06:20 PM   #2
wealdenengineer
10 tenths
United Kingdom
 
Join Date: Oct 2001
Location: East Sussex, UK
Posts: 1,932
Re: Weber ida fire extinguisher nozzle positions

No ! Nick, are you using carbs or FI ?
This is what appears quite a simple question which gets more complicated as you understand the issues involved. The safest answer is don't have a fire in the first place, and if you do don't panic, more damage is caused by panic reaction than the fire itself. First always dump the residual fuel pressure in the system , I do this with a built in system that reacts instantly either the pumps or ignition is turned off. You can also kill an internal carb fire by keeping the engine turning over, each induction stroke will suck unburnt fuel into the manifold, and is a well used method of dealing with a fire in the carb trumpet. What you do not want is to suck the corrosive extinguishant into the engine, that's an immediate engine rebuild if you do!
If you have fuel leak else where in the fuel system , particularly on the pressurised side of the pumps, then it is imperitive that all all possible ignition sources are immediately isolated as far as possible, this happened in my case when I realised that I had liquid fuel being pumped over the engine side of the bulkhead window while doing well in excess of 130 mph at Stavelot on the Spa circuit in Belgium, killing all ignition sources whilst continuing at high speed to the pi t lane marshalls fire post, they were surprised to see a dead engined GT40 arriving at unabated speed with a very scared driver at the wheel, but the action saved a very big potentially car destroying fire. Frank
wealdenengineer is offline   Reply With Quote
Old 19th December 2017, 06:37 PM   #3
Nick Brough's Avatar
Nick Brough
Bronze Supporter
United Kingdom
 
Join Date: Apr 2006
Location: Warrington UK
GT40: SGT 351W G50
Posts: 1,761
Re: Weber ida fire extinguisher nozzle positions

Quote:
Originally Posted by wealdenengineer View Post
No ! Nick, are you using carbs or FI ?
This is what appears quite a simple question which gets more complicated as you understand the issues involved. The safest answer is don't have a fire in the first place, and if you do don't panic, more damage is caused by panic reaction than the fire itself. First always dump the residual fuel pressure in the system , I do this with a built in system that reacts instantly either the pumps or ignition is turned off. You can also kill an internal carb fire by keeping the engine turning over, each induction stroke will suck unburnt fuel into the manifold, and is a well used method of dealing with a fire in the carb trumpet. What you do not want is to suck the corrosive extinguishant into the engine, that's an immediate engine rebuild if you do!
If you have fuel leak else where in the fuel system , particularly on the pressurised side of the pumps, then it is imperitive that all all possible ignition sources are immediately isolated as far as possible, this happened in my case when I realised that I had liquid fuel being pumped over the engine side of the bulkhead window while doing well in excess of 130 mph at Stavelot on the Spa circuit in Belgium, killing all ignition sources whilst continuing at high speed to the pi t lane marshalls fire post, they were surprised to see a dead engined GT40 arriving at unabated speed with a very scared driver at the wheel, but the action saved a very big potentially car destroying fire. Frank
Frank, thanks for the information, although unexpected it makes sense now. I have carbs fitted, I assume then the best thing to do with my expensive possible white elephant system is to have it as an absolute last resort, with the nozzles aiming as far away from the intakes as possible, to save the car or occupants, and hopefully never to be used, and above all don't panic Captain Mainwaring.

Glad to know your incident ended safely for everyone, the look on the fire marshalls faces must have been priceless.
__________________
Regards
Nick

Last edited by Nick Brough; 19th December 2017 at 06:50 PM.
Nick Brough is offline   Reply With Quote
Old 19th December 2017, 07:41 PM   #4
wealdenengineer
10 tenths
United Kingdom
 
Join Date: Oct 2001
Location: East Sussex, UK
Posts: 1,932
Re: Weber ida fire extinguisher nozzle positions

Nick, call me for more info if required, Frank
wealdenengineer is offline   Reply With Quote
Old 22nd December 2017, 01:30 PM   #5
KarlWood
Rookie
United States
 
Join Date: Oct 2014
Location: San Francisco
GT40: CAV #53
Posts: 67
Re: Weber ida fire extinguisher nozzle positions

Frank, I am wondering if it would depend on the extinguishant used. I have a fire suppression system using DuPont FE-36. It is a gas and doesn't leave any residual liquid or foam.

I did have the case to use it once! It was a most surreal experience. It was before I had the webers setup properly (they were a mess!). The car was hot after a spirited drive. I went to restart it to move it. It spat back and ignited a small fireball in the rear view. Your suggestion of keeping the engine turning over would have been the best approach, but that thought didn't go through my mind in the next few milliseconds! My initial though was "should I pull the cord on the fire extinguisher"...."no, I then have to get it refilled and that will be a pain... and what happens if something occurs before then"...."it will probably just quickly burn out and disappear".... "what the hell am i thinking..... this is exactly why you had the system installed you dumb ass!!!!". So I pulled the cord! All that thinking was in a very very small amount of time. The fire went out very quickly, nothing was damaged, just a faint amount of soot on the rear window above the carbs. My wife appeared a couple of minutes later and I was still sat there with a rather bewildered look on my face. I told her, "nope I am not going to move the car over" as she had suggested a couple of minutes before... "I think I am just going to leave it there, I quite like it there while it cools down!!".
Since then I have had the carbs rebuild, I have set the timing properly and set the fuel pressure. All is good! Quite the experience, and I was VERY glad I had the fire suppression system put in only about 2 weeks before!
KarlWood is offline   Reply With Quote
Old 22nd December 2017, 04:15 PM   #6
wealdenengineer
10 tenths
United Kingdom
 
Join Date: Oct 2001
Location: East Sussex, UK
Posts: 1,932
Re: Weber ida fire extinguisher nozzle positions

Good one Karl, I like the story . If running carbs, particularly Webers, it is, in my experience, essential to dump all residual fuel pressure from the system immediately you turn off the engine, and most particularly when the engine is very hot, and just as importantly to be using phenolic spacers between the inlet manifold and the carbs to reduce heat soak penetration into the carbs from the engine. Fire extinguishers are a last resort, but as you know yourself are the first thing you think of in this situation, so, as I said, first don't have a fire, then don't panic.
wealdenengineer is offline   Reply With Quote
Old 23rd December 2017, 04:39 AM   #7
Nick Brough's Avatar
Nick Brough
Bronze Supporter
United Kingdom
 
Join Date: Apr 2006
Location: Warrington UK
GT40: SGT 351W G50
Posts: 1,761
Re: Weber ida fire extinguisher nozzle positions

Quote:
Originally Posted by wealdenengineer View Post
Good one Karl, I like the story . If running carbs, particularly Webers, it is, in my experience, essential to dump all residual fuel pressure from the system immediately you turn off the engine, and most particularly when the engine is very hot, and just as importantly to be using phenolic spacers between the inlet manifold and the carbs to reduce heat soak penetration into the carbs from the engine. Fire extinguishers are a last resort, but as you know yourself are the first thing you think of in this situation, so, as I said, first don't have a fire, then don't panic.
Frank,

It was great talking to you the other day, really interesting thank you. I have ordered a set of the phenolic spacers you suggested. I was also very interested in what you said about having up to 1/2 inch of petrol sat on top of the butterfly after switch off due to the residual pressure, as I had seen this happen on one off my carbs and was one of the reasons for buying a fire extinguisher system. I will now be turning off the pump a good way before I get to any destination or before switching off the engine, to hopefully avoid it happening.
__________________
Regards
Nick
Nick Brough is offline   Reply With Quote
Old 23rd December 2017, 11:05 AM   #8
wealdenengineer
10 tenths
United Kingdom
 
Join Date: Oct 2001
Location: East Sussex, UK
Posts: 1,932
Re: Weber ida fire extinguisher nozzle positions

Nick, there is another solution, instant fuel pressure dump back to the tanks via a solenoid valve, this takes away any residual pressure from the incoming fuel lines to the carbs, much safer!
wealdenengineer is offline   Reply With Quote
Old 23rd December 2017, 11:45 PM   #9
BenL's Avatar
BenL
9 Tenths
United States
 
Join Date: Apr 2004
Location: USA
Posts: 975
Re: Weber ida fire extinguisher nozzle positions

Years ago, I remember being told if there's a backfire to stomp on the gas pedal to draw the flames back into the carbs.

When driving normally, I'll try to remember to switch off the fuel pump before turning off the car (ignition and fuel pump are separate switches).

I've been thinking about phenolic spacers for the webers to prevent vapor lock, does anyone have a particular recommendation?
BenL is offline   Reply With Quote
Reply

Tags
extinguisher, fire, fires, place, thinking


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 06:25 PM.