Hoodliner installed with PICS
#11
Yep, I removed mine and just rattle canned some black since it seems LR didn't paint the hood under the liner. No ill effects yet, and as interesting as the fire theory sounds I would think it would need to be quite a hot fire to melt the tabs on the outside edges allowing the entire liner to drop. I doubt that it would actually make much difference, though I have no real data to back that up.
Last edited by Alex_M; 08-20-2015 at 01:47 PM.
#12
#13
Ok, so I decided to do some research. It would seem that most plastic tabs are made of nylon. The melting point of Nylon 6 is 428 degrees F (220 C) and the melting point of Nylon 66 is 509 F (265 C). Sh*t, I've got class in 10 minutes. I'll come back and finish this mathing around 6.
#15
Ok, so this is some VERY complicated math. Well over my head and exactly why I'm no longer a mechanical engineering student. None the less, I believe the following is correct... enough; engine bay were 120 F and you had a gasoline fire that was burning at 1650 F at it's hottest point (the center), and an approximate 15^2ft of air in the engine bay (I think that's low) with a distance of ~2ft from the flame to the farthest tab. Air has an approx conductivity of .024W/(m K). I *believe* that there would only be a 71.6 degree temperature increase of the tab, pushing it to approximately 192 degrees which is still approximately half of the melting temperature of the nylon tab at the surface.
Now, be aware that all of the math that I have done is absolute bullsh*t because I used formulas used to calculate heat loss through pipes and all that kind of jazz, and I have no damn idea what I'm doing, but the numbers are so far separate that I also believe the theory that the tabs will melt for the mat to fall and save the passengers is also bullsh*t. Not only because of the numbers, but also because it will make almost no difference. The mat will not fall past the ABS/Master Cylinder/Intake/Fuse Box/Battery Box/etc, meaning that even if it did fall it would not wrap around the engine to extinguish the flames because the fire would still be receiving oxygen from all four sides and the bottom with a maximum loss of 4" with an approximate average loss of 2" of air area on the top.
Now, be aware that all of the math that I have done is absolute bullsh*t because I used formulas used to calculate heat loss through pipes and all that kind of jazz, and I have no damn idea what I'm doing, but the numbers are so far separate that I also believe the theory that the tabs will melt for the mat to fall and save the passengers is also bullsh*t. Not only because of the numbers, but also because it will make almost no difference. The mat will not fall past the ABS/Master Cylinder/Intake/Fuse Box/Battery Box/etc, meaning that even if it did fall it would not wrap around the engine to extinguish the flames because the fire would still be receiving oxygen from all four sides and the bottom with a maximum loss of 4" with an approximate average loss of 2" of air area on the top.
#16
#17
Yeah. I didn't believe it either.
Unless the mat is specifically made of some kind of melty fire suppressant material which drips all over the engine I don't buy that the nylon tabs melt, dropping the mat.
I know that certain powder fire extinguishers are designed to smother flames with the melted powder as it comes into contact with heat, but I don't think this is the case.
Unless the mat is specifically made of some kind of melty fire suppressant material which drips all over the engine I don't buy that the nylon tabs melt, dropping the mat.
I know that certain powder fire extinguishers are designed to smother flames with the melted powder as it comes into contact with heat, but I don't think this is the case.
#18
Ok, so this is some VERY complicated math. Well over my head and exactly why I'm no longer a mechanical engineering student. None the less, I believe the following is correct... enough; engine bay were 120 F and you had a gasoline fire that was burning at 1650 F at it's hottest point (the center), and an approximate 15^2ft of air in the engine bay (I think that's low) with a distance of ~2ft from the flame to the farthest tab. Air has an approx conductivity of .024W/(m K). I *believe* that there would only be a 71.6 degree temperature increase of the tab, pushing it to approximately 192 degrees which is still approximately half of the melting temperature of the nylon tab at the surface.
Now, be aware that all of the math that I have done is absolute bullsh*t because I used formulas used to calculate heat loss through pipes and all that kind of jazz, and I have no damn idea what I'm doing, but the numbers are so far separate that I also believe the theory that the tabs will melt for the mat to fall and save the passengers is also bullsh*t. Not only because of the numbers, but also because it will make almost no difference. The mat will not fall past the ABS/Master Cylinder/Intake/Fuse Box/Battery Box/etc, meaning that even if it did fall it would not wrap around the engine to extinguish the flames because the fire would still be receiving oxygen from all four sides and the bottom with a maximum loss of 4" with an approximate average loss of 2" of air area on the top.
Now, be aware that all of the math that I have done is absolute bullsh*t because I used formulas used to calculate heat loss through pipes and all that kind of jazz, and I have no damn idea what I'm doing, but the numbers are so far separate that I also believe the theory that the tabs will melt for the mat to fall and save the passengers is also bullsh*t. Not only because of the numbers, but also because it will make almost no difference. The mat will not fall past the ABS/Master Cylinder/Intake/Fuse Box/Battery Box/etc, meaning that even if it did fall it would not wrap around the engine to extinguish the flames because the fire would still be receiving oxygen from all four sides and the bottom with a maximum loss of 4" with an approximate average loss of 2" of air area on the top.
That's a great answer. Given the fact that the hood blanket doesn't do much except muffle the ticking, wheezing, clunking, and whining sounds from my engine, I would rather have dynamat. That's next on my list. Thanks, OP for showing everyone how to do it!
Now for a reverse mod (mod request). A bright, automatic, hood light, preferably LED, so I don't have to eat oil and antifreeze from mouthing my flashlight.
#19
Thanks Charlie, really appreciate that. I actually considered law for a time but decided it was a lot of writing and researching. As much as I'd enjoy the actual court room time and perhaps even some of the mulling over documents to find loopholes, I don't think I could do it long term.
As for your engine bay light, I think that would be simple. You could most likely go to walmart and buy one of their simple LED kits that people install inside their cars, then just wire it up through a relay which is activated by the hood switch next to the air box (or where the airbox used to be) and perhaps a switch between the hood switch and the relay so you have the ability to turn it off while the hood is open if you so desire. I'd probably mount it to the underside of the hood with double sided tape if you could find a tape that would withstand ~200 degrees. If you couldn't then you could screw it into some of the hood framing with short screws just like the hood prop.
As for your engine bay light, I think that would be simple. You could most likely go to walmart and buy one of their simple LED kits that people install inside their cars, then just wire it up through a relay which is activated by the hood switch next to the air box (or where the airbox used to be) and perhaps a switch between the hood switch and the relay so you have the ability to turn it off while the hood is open if you so desire. I'd probably mount it to the underside of the hood with double sided tape if you could find a tape that would withstand ~200 degrees. If you couldn't then you could screw it into some of the hood framing with short screws just like the hood prop.