Help educate me on the most likely reason these aircooled cars catch fire. Is this endemic to the design,carburation choices, sloppy engine builds. How can we avoid these events?
Original Post
Replies sorted oldest to newest
Help educate me on the most likely reason these aircooled cars catch fire. Is this endemic to the design,carburation choices, sloppy engine builds. How can we avoid these events?
I don't think it's an epidemic, but when we see a Speedster go up it hurts doesn't it? Imagining all that work into the car go up.
Issues are fuel line, backfires (bad tune), fuel pump, proper carb adjustment, leaking gasket on fuel pump, leaking line on fuel pump etc.. Because of the excessive heat, fuel is an issue, fuel line going through the doghouse and the grommet is missing. And.... here's the kicker. Many (most) of the Aircooled motors in these cars have magnesium blocks. Once that catches fire, run, run away.
So not only we do we need to check suspension bolts, steering bolts, wheel lugs, brakes etc.. in the spring. Pay particular attention to what going on in the engine compartment. If you buying a used one, even a new one I think you need to do your due diligence and look at things to make sure all is AOK.
Last year I saw 2 car fires. One was a Jetta and the other some sort of Mazda, so it happens. But you can reduce your chances easily.
Issues are fuel line, backfires (bad tune), fuel pump, proper carb adjustment, leaking gasket on fuel pump, leaking line on fuel pump etc.. Because of the excessive heat, fuel is an issue, fuel line going through the doghouse and the grommet is missing. And.... here's the kicker. Many (most) of the Aircooled motors in these cars have magnesium blocks. Once that catches fire, run, run away.
So not only we do we need to check suspension bolts, steering bolts, wheel lugs, brakes etc.. in the spring. Pay particular attention to what going on in the engine compartment. If you buying a used one, even a new one I think you need to do your due diligence and look at things to make sure all is AOK.
Last year I saw 2 car fires. One was a Jetta and the other some sort of Mazda, so it happens. But you can reduce your chances easily.
Attachments
Images (1)
Good advice Mike. I moved my coil up onto the fan shroud ,per your (and others) suggestion and I feel a little better now about my chances of avoiding an unscheduled plactic BBQ. Also you can see all that fuel related stuff and keep it clean in there. Thanks.
Always periodically check the location and condition of your fuel lines, including all junctions. Check them for leaks and cracks. Do the same for fuel filters. Make sure the lines in you engine compartment are routed as far as possible from major heat sources such as engine tin, cooling shroud, etc. Also make sure they're routed away from potential sources of spark like the ignition coil.
Just to amplify Mike's remarks:
Issues are fuel line: Make sure it is kept far away from both heat generators AND ignition wires, plugs and coil. I've mounted my coil on the driver's inner fender wall for that reason. Remember that the fuel line is usually high on these engines and gravity will want to pull it down to where the exhaust heat is. Don't let it.
Backfires (bad tune): of Special concern is popping UP through the carburetor, as it's spraying raw gas onto the inside of the air cleaner. If it coughs a few times and coughs up a fireball, well, you get the idea.
Fuel pump: Two things; a mechanical pump sits on top of the engine case. If it gets a pinhole in the pump diapraghm it can leak raw gas down into the crankcase with the potential to ignite. To prevent this, remove the mechanical fuel pump, put a cover over the hole and install a rotary fuel pump up under the gas tank in the front instead.
Leaking line on fuel pump: Just check to see that all connections are tight and leak-free and there are no pinholes along its' length.
Proper carb adjustment: In particular, make sure the floats are set at the correct height and pilot valves are not leaking, causing the bowls to overflow when the engine is turned off and run raw gas down into the cylinders - probably won't catch fire, but it's bad, just the same.
"Because of the excessive heat, fuel is an issue, fuel line going through the doghouse and the grommet is missing." also, if the fuel line goes through the engine firewall - it should have a good grommet there, too, and you should check where the hose goes through anything every Spring t make sure there is no abrasion there that might leak. Remember that the engine vibrates and moves around a lot when running and will wear anything attached both to it and something else stationary (like a firewall).
"And.... here's the kicker. Many (most) of the Aircooled motors in these cars have magnesium blocks. Once that catches fire, run, run away."
Mine's Aluminum, but either one will go up like a fireball.
Issues are fuel line: Make sure it is kept far away from both heat generators AND ignition wires, plugs and coil. I've mounted my coil on the driver's inner fender wall for that reason. Remember that the fuel line is usually high on these engines and gravity will want to pull it down to where the exhaust heat is. Don't let it.
Backfires (bad tune): of Special concern is popping UP through the carburetor, as it's spraying raw gas onto the inside of the air cleaner. If it coughs a few times and coughs up a fireball, well, you get the idea.
Fuel pump: Two things; a mechanical pump sits on top of the engine case. If it gets a pinhole in the pump diapraghm it can leak raw gas down into the crankcase with the potential to ignite. To prevent this, remove the mechanical fuel pump, put a cover over the hole and install a rotary fuel pump up under the gas tank in the front instead.
Leaking line on fuel pump: Just check to see that all connections are tight and leak-free and there are no pinholes along its' length.
Proper carb adjustment: In particular, make sure the floats are set at the correct height and pilot valves are not leaking, causing the bowls to overflow when the engine is turned off and run raw gas down into the cylinders - probably won't catch fire, but it's bad, just the same.
"Because of the excessive heat, fuel is an issue, fuel line going through the doghouse and the grommet is missing." also, if the fuel line goes through the engine firewall - it should have a good grommet there, too, and you should check where the hose goes through anything every Spring t make sure there is no abrasion there that might leak. Remember that the engine vibrates and moves around a lot when running and will wear anything attached both to it and something else stationary (like a firewall).
"And.... here's the kicker. Many (most) of the Aircooled motors in these cars have magnesium blocks. Once that catches fire, run, run away."
Mine's Aluminum, but either one will go up like a fireball.
The piddly grommet. Here's a tip I did and works great.
If you need to replace that grommet while the engine and fuel line are in the car and attached you have no choice but to cut the grommet to fit around the line so you can insert in the hole. Hmm... terrible job!
I took a piece of rubber fuel line (about 1") and sliced it open so that it will fit over the fuel line. Then push it into the hole and voila a better job!
If you need to replace that grommet while the engine and fuel line are in the car and attached you have no choice but to cut the grommet to fit around the line so you can insert in the hole. Hmm... terrible job!
I took a piece of rubber fuel line (about 1") and sliced it open so that it will fit over the fuel line. Then push it into the hole and voila a better job!
Attachments
Images (1)
