fire, anyone: where & why?

Usually it starts in the engine compartment from the failure of a rubber gasoline hose arranged in the wrong place near heat, or it gets old and cracks and leaks raw fuel.

Less often, the carburetors may cough up a small flame that ignites the paper air filters we all use inside of the air cleaners.  

Even less often a mechanical fuel pump diaphragm may fail leaking raw gas either into the crankcase or out the pump breather hole and onto the engine, or a carburetor float valve may stick open and leak raw gas either into the cylinders or possibly onto the engine.

Remember that the vast majority of these cars still use carburetors, something that fewer and fewer people understand how to operate or adjust properly as time goes on (the last carbureted factory car was built in the 1980’s) so the chance of mis-adjustment is always there.

Many found that an engine fire got hot so fast - they couldn't open the engine lid to shoot at the fire's base.  Shooting the extinguisher thru the engine grill is ineffective.  There are several engine bay fire extinguishing systems (BlazeCut) that are advertised to work - BUT I'd still have portable extinguisher available.

I had a clogged jet and the engine backfired while driving. The motor started to run very poorly so I pulled over. I happened to look in the rear view mirror and saw flames coming out the engine grill. There was another Speedster following behind me and he pulled over as well. We opened the engine lid quite easily and he put out the fire with a Halguard fire extinguisher. I pulled off the roasted air filter, pulled out the jets and cleaned them out with a straightened out staple from the route map. Put everything back together and drove back to the hotel. The next day I drove home 150 miles without any issues.

I hope there wAs not to much damage to the car

Robert M posted:

I had a clogged jet and the engine backfired while driving. 

...and that is how it almost always happens. I’ve nearly burnt twice, and both times it was a backfire caused by an ignition issue. Ignition or plugged jet, a spitting backfire is no bueno. 

In my both instances with my car, keeping the engine running saved the day. The engine stayed running, and the vacuum of the engine sucked the flame down the intake runner. Stuff high in the carb melted, and the inside of the air-cleaner elements were singed, but nothing became a flame that the vacuum could not overcome. 

If I had shut the engine off, or caught the filter elements on fire— I would have been screwed. 

IaM-Ray posted:

I hope there wAs not to much damage to the car

I didn't take pictures of the carburetor and filter, duh what was I thinking, but the damage was limited to a fully melted air filter element, the blackening of the underside of the engine lid, scorched grill badges, melted third brake light, and some light discoloration on the top of the lid.

I took the lid off and Anand buffed out all of the surface discoloration on the top of the lip and most of the blackening on the underside of the lid. I sanded down the top of the rain hat and repainted it. I redid the third brake light, and put on some new grill badges. I cleaned all of the jets when I got home and replaced the air filter element with some air filter elements that had a wire screen on the inside of the element which was supposed to add some fire resistance to them. Thankfully I never got a chance to try out that feature.

I think what helped was the filters had been freshly cleaned and properly oiled with the K&N solution. That may have slowed the fire down a bit but I have nothing scientific to back up that claim.

I'm pretty sure I took pictures of your filter and grill or at least saw pictures of them. They may have even been posted on the SOC.  I'll look for them. 

@Robert M

I was sorry to hear about your flame up...

I can see that you may be adding to your maintenance routine from now on as you can't neglect those carbs.  I often think of putting a racing filter with a higher caliber gaz filter that has a cartridge to eliminate impurities in the line.   Presently, I have one after the tank before the pump and one in the engine compartment.   Better filtration would be a better fit for injectors and carburetors. 

I wonder if that would help keep those jets clean for you. 

On my subie my issue that I do,  is I must keep my K&N filter clean and my MAF sensor cleaned as well otherwise I could be riding a bucking bronco that is no fun without the fire though.