I want to be cautious and diplomatic about this, but for anyone who uses foam filters and who experiences carb backfiring or has used carb cleaner recently, be very careful.
I'll try and keep the story short. I started this at the end of another thread so I thought I'd give it its own thread. I have had ITG filter socks on my car for years. They came with the car and are very old. A recent incursion of grit into my carbs prompted me to invest in some proper backplate air filters for my SU carbs. For budget reasons I opted for the Ramair foam filters.
I had only just fitted them last weekend, and hadn't fired the car up due to a regrettable moment of idiocy with my gearbox immediately after fitting them. So they had sat on my car for about 4/5 days before I was able to fire up and give the car a drive.
My car is hard to start when cold. The quickest way to get it going is to spray a small amount of carb cleaner into the body... just a squit... and it will fire up off that and then pull in fuel thereafter. Not ideal but it's what I'm working with at the moment.
The Ramair filters can be clipped off, making it easy enough to do this. So I had done that, got the car running, then stuck the filters on. Then the car stalled again before I could get back in and give it some revs of encouragement. So I restarted again, and one of my carbs backfired. The hood was still up, thankfully, because the next thing I knew was a column of thick grey smoke billowing out from my engine bay. Running round to see what the hell was going on, I discovered that the frontmost Ramair filter had caught fire, and was not going to extinguish again. It burned fast and powerfully and the fire rapidly ate its way through all of the foam, dripping fireballs of molten foam into my engine bay and spreading the fire dangerously close to fuel lines and electrics. The fire roared quite fiercely, and I thought it was the end of my car. By the time I'd reached for my fire extinguisher and got it to work, the worst of it was over. It was a flash in the pan kind of fire and it died back down leaving me with one empty wire cage where my air filter used to be....
I was very surprised by this. I would have thought the last thing an air filter should do would be to catch fire and burn through so completely. By comparison, my ITG socks have endured numerous carb-cleaner fuelled carb backfires over the last few months and they don't show so much as a singe mark inside or outside.
I spoke to Ramair yesterday and they seemed very surprised to hear it. I asked if their foam was fire retardent and what they said, more or less, is that the foam itself isn't, but it gets coated in a fire retardant agent before (or after) construction of the filter. I asked them if it was possible that a batch of foam had missed the fire retardant application stage. They hoped not and went off to perform a fire test on some foam.
What they said when they came back to me was that they had set fire to some of their foam in the workshop, and it had burned, but it had not spread wildly it had eventually extinguished itself after burning locally. For me it's not so much the encouraging fact that their foam fire went out... it's the wholly discouraging fact that their foam burned in the first place. If one was to experience a fire while the engine is running and sucking lots of air in, that would surely be absolutely disastrous as the air intake would accelerate the burning. It seems a little crazy to me to have air filters made out of a flammable material, even if it is coated in fire retardant that can slow the fire to a stop eventually.
The upshot of this is that I haven't pushed them to provide a replacement, and they didn't feel they should offer one after reflecting on the situation. Their argument was that there was a backfire and the possible presence of a flammable agent (carb cleaner) could have promoted the foam catching fire, and that is not their responsibility. I have accepted that, because it's true, and I'm not going to try and make them responsible for the fact that my car backfired and possibly spat carb cleaner at the foam. They dealt with my call as best they could, but didn't feel obliged to offer me a replacement. Having watched my car become engulfed in the thick smoke of burning filter foam, I really don't want to put those filters on my car ever again, so I didn't feel inspired to haggle for a replacement anyway.
My ETG socks are back on and they are made of an entirely different kind of foam that is at its core, inherently fire resistant. My pockets are £80 lighter as a result of this experience, and the air filters didn't even make it into first gear, but that's life.
Anyone with carb backfires or the need to apply carb cleaner ... be careful which filters you choose. Some of them are incredibly flammable!
Having looked online I find I'm not the only one to have this experience. There are some interesting comments in various forums where this brand of filters are vilified for causing a number of disastrous engine fires, sometimes whilst the cars were actually in motion.
I'll try and keep the story short. I started this at the end of another thread so I thought I'd give it its own thread. I have had ITG filter socks on my car for years. They came with the car and are very old. A recent incursion of grit into my carbs prompted me to invest in some proper backplate air filters for my SU carbs. For budget reasons I opted for the Ramair foam filters.
I had only just fitted them last weekend, and hadn't fired the car up due to a regrettable moment of idiocy with my gearbox immediately after fitting them. So they had sat on my car for about 4/5 days before I was able to fire up and give the car a drive.
My car is hard to start when cold. The quickest way to get it going is to spray a small amount of carb cleaner into the body... just a squit... and it will fire up off that and then pull in fuel thereafter. Not ideal but it's what I'm working with at the moment.
The Ramair filters can be clipped off, making it easy enough to do this. So I had done that, got the car running, then stuck the filters on. Then the car stalled again before I could get back in and give it some revs of encouragement. So I restarted again, and one of my carbs backfired. The hood was still up, thankfully, because the next thing I knew was a column of thick grey smoke billowing out from my engine bay. Running round to see what the hell was going on, I discovered that the frontmost Ramair filter had caught fire, and was not going to extinguish again. It burned fast and powerfully and the fire rapidly ate its way through all of the foam, dripping fireballs of molten foam into my engine bay and spreading the fire dangerously close to fuel lines and electrics. The fire roared quite fiercely, and I thought it was the end of my car. By the time I'd reached for my fire extinguisher and got it to work, the worst of it was over. It was a flash in the pan kind of fire and it died back down leaving me with one empty wire cage where my air filter used to be....
I was very surprised by this. I would have thought the last thing an air filter should do would be to catch fire and burn through so completely. By comparison, my ITG socks have endured numerous carb-cleaner fuelled carb backfires over the last few months and they don't show so much as a singe mark inside or outside.
I spoke to Ramair yesterday and they seemed very surprised to hear it. I asked if their foam was fire retardent and what they said, more or less, is that the foam itself isn't, but it gets coated in a fire retardant agent before (or after) construction of the filter. I asked them if it was possible that a batch of foam had missed the fire retardant application stage. They hoped not and went off to perform a fire test on some foam.
What they said when they came back to me was that they had set fire to some of their foam in the workshop, and it had burned, but it had not spread wildly it had eventually extinguished itself after burning locally. For me it's not so much the encouraging fact that their foam fire went out... it's the wholly discouraging fact that their foam burned in the first place. If one was to experience a fire while the engine is running and sucking lots of air in, that would surely be absolutely disastrous as the air intake would accelerate the burning. It seems a little crazy to me to have air filters made out of a flammable material, even if it is coated in fire retardant that can slow the fire to a stop eventually.
The upshot of this is that I haven't pushed them to provide a replacement, and they didn't feel they should offer one after reflecting on the situation. Their argument was that there was a backfire and the possible presence of a flammable agent (carb cleaner) could have promoted the foam catching fire, and that is not their responsibility. I have accepted that, because it's true, and I'm not going to try and make them responsible for the fact that my car backfired and possibly spat carb cleaner at the foam. They dealt with my call as best they could, but didn't feel obliged to offer me a replacement. Having watched my car become engulfed in the thick smoke of burning filter foam, I really don't want to put those filters on my car ever again, so I didn't feel inspired to haggle for a replacement anyway.
My ETG socks are back on and they are made of an entirely different kind of foam that is at its core, inherently fire resistant. My pockets are £80 lighter as a result of this experience, and the air filters didn't even make it into first gear, but that's life.
Anyone with carb backfires or the need to apply carb cleaner ... be careful which filters you choose. Some of them are incredibly flammable!
Having looked online I find I'm not the only one to have this experience. There are some interesting comments in various forums where this brand of filters are vilified for causing a number of disastrous engine fires, sometimes whilst the cars were actually in motion.
