Saturday, two of the guys from the Sportbike forum came up to test the material. Unfortunately, we were still in the single layer mode and like me on Saturday, there wasn't a lot of difference. But we're learning as we go along. We had a blast though and they followed me around the Plant, before we ended up at the air park.



This is what the passenger side floorboard for the manual trans C3 looks like and there was a whole lot of to get it to fit!



This is the beginning layup of the driver's side, with the adhesive. It held up well.



Now we're putting the Kapton on the outside of the shield. Yesterday, I added another layer on the inside, to double down on the material.



Finished Driver's side shield:



Driver's side installed.



Part 2: Sunday, I'm adding the Kapton-Fiberglass pillow to the inside of the shield and you can see the extra layer of Kapton on the inside of the shield as well. We're at four layers, including the shield.



Pillow Detail: This is what solved the heat problem in the car. Extra layers and insulation. I remembered the linkee I put out from Dupont that detailed the 26 layers they put in the astronaut suits. That's what put me on track to do this and it was successful.



Used the BK Multimeter, with the temp sensor, because it was more accurate and after twenty minutes, it was still only 98 degrees. It topped out at 107-111 degrees and barefoot in the car for 45 minutes on a 98 degree day, I wasn't uncomfortable, roasted or dying in a rolling toaster oven and feeling the furnace blast.

 

This is what the interior firewall of my 70 looks like.
..........................
The 68 and 69 Corvettes had an extensive insulation under the floor (on the outside of the floor pans), and the insulation ran up 1/2 way on the engine side of the firewall... for whatever reason...probably money, they dropped this feature on the 70 and up Corvettes. The parts to add this insulation system are still available and it's very inexpensive to do. I'd say one of the first things to do to insulate your car is to retrofit the 68/69 insulation package. The major parts houses will have drawings of these parts. Also, of course the 68 and 69 AIMs have drawings I'd guess.
e re

 

I rarely drive my C3 on warm days, it's more of my early morning or evening driver now. It just gets too friggin hot even with the insulation installed on warm days. Luckily the winters in So Cal are mild so I put more mileage on it during the winter than the summer. I drive the C5 or C6 on the hot summer days. I know a bunch of the California Stingrays just took a long trip during this current heat wave but I refuse to drive it when it's hot. Just doesn't make for a comfortable ride.

 

Update: We're going into the Fall season and Winter's only a few months away. No hurry now, but I'm going to continue to develop the Heat Shield for the C3 Corvettes. This gives us time, if the product is successful for a Spring release and also, to make up fiberglass molds for the automatic C3's on the Passenger side.

If you want to go the DEI route, please do so and tell us how it works, I'm curious as well. I called a place here in SoCal that sells a similar product and they are either full custom, or you can buy a panel at $67 a square foot. The Driver's side measures 29" by 25" inches, so you can do the math. It is a single layer of Inconel sandwiched with a layer of insulation and is another method of defeating the heat. My approach is different, it may be no better, but it can't be worse, based on what I've tested so far.

This week, I will be making up a second blanket of the Kapton film, with fiberglass insulation and installing it on top of the shield. I will then go on a long distance test of at least an hour to an hour and a half this weekend and use the BK Multimeter to check the temps. I was happy with nearly an hour in the car on Saturday, so looking forward to seeing how it works this weekend.

The Driver's side installs easily, without removing the exhaust. It is a direct bolt on and I will be sourcing clamps for the transmission crossmember (right now, it's very heavy duty nylon 1/2" wide ties).

If the testing works out (and I'm not interested in bogus results to save face, if it fails, it fails) then next week, the first prototype driver's floor shield gets dropped and I'm making up a new one, using high temp adhesives and am making up new blankets as well.

The test blankets are made with regular fiberglass insulation, like you and I would find at Home Depot or Lowes, which has a low density. I found a far denser fiberglass insulation blankets that comes in thicknesses as little as 1/8". With thin sections like that, you can make up multiple layers (like the space suits mentioned) and get even more protection.

http://bgf.com/prodInsulSilco.asp

Another intriguing material I found is Aluminum Foam. Now that's some strange stuff, I've never seen before. And it's properties might make it ideal for something along the lines of what we're trying to accomplish here.

http://www.ergaerospace.com/Aluminum-properties.htm

Next update will be this weekend, with real-world test results from the extended test drive out in the desert.

Thanks for following.

 

F22 - Sent you a PM. Let me know if this is worth looking into.

Thanks,
Adam

 

Adam, I got your PM and thanks!

 

Thanks for the update... Hope it works out for you!

I just ordered some tunnel shield II, Ill post some pics once it's installed. I'm a long way from done so I will not be able to report any data.

The DEI Tunnel shield II is $117.00 for a 48X42 sheet, thats about $9.00 a sq ft, If I did my math correct...Seems pretty cheap for cool feet!

 

Cool! No, that's not that expensive at all. Pretty reasonably priced too and that's about the right amount for both sides (I measured 29x25 or so for the driver's side). Good luck with the install and looking forward to hearing how it worked out. Pics and data are welcome here!

 

That looks awesome man.

I used that internal exhaust coating.... gave temps ~10 degrees cooler.
http://forums.corvetteforum.com/c3-t...ting-test.html

 

Thanks rafalc! I had mine coated too and everything helps, that's for sure!

 

F22, was thinking (that can and does get me in trouble often!), if when you make the fiberglass shields would you sell them without the fancy heat barrier? It sounds like that stuff you scored will be/is expensive and I'm not sure it will be in my budget but hopefully the fiberglass shields wont be too costly.

Thanks and I hope I'm not sounding like a cheap bastard!

 

I can sell you the shields alone. One side may be metal, esp. the driver's side, because I can't see it being too much different between the automatics and the manuals. It's the passenger side, that's a royal pita!

I've still got to get an automatic Corvette in the shop (and yes, I have access to a '72 C3, with an automatic, that the owner will let me 'borrow'), so I can put it up on jackstands and go through the process of creating a shape, that I can make a mold out of, that will fit. This is a laborious process! I think it's going to be at least a few weeks to a month, before I get that C3 in my shop.

 

Cool, I have a 4 speed (soon to have a 5 speed though), so the ones you are working on now will work for me. I just need to check and see that the original heat shield mounts are there and if not figure out mounting

 

Update: Last night, I got to work (after work!) at the shop and started on the second pillow or pad (we'll call it a pad from this point forward). I then jacked the '74 up again, so I could drop the driver's side and add the second pad. It was a tight squeeze, because of the 'potato chip bag' effect of the air in the pad, along with the low density fiberglass from Lowe's that I'm using.

Here is the process of making up the pad.

Laying it out and cutting it:



Sizing up the low density fiberglass, but leaving a 2" space all around for the adhesive:



Now we're applying the adhesive and going heavy on the edges, so I can seal it up.



Replacing the layer of the various pieces of the low density fiberglass, back on top of the glued surface. Even that, took some thinking, so I used a piece of cardboard to layup the fiberglass first, then slid it off the cardboard onto the glued surface as I pulled the cardboard out from underneath. Otherwise, it'd be sticking as I tried to rearrange the various chunks.



Gotta glue the other half. Pfffft and then step away from the cloud of adhesive spray, so I don't die an earlier death than I'm supposed to.



Fold it over and squeeze out as much air as possible, compressing it and sealing the edges. Not perfect, but not bad either. I was happy with the results.



Done!



I installed it last night, laying it under the first layer and buttoned it up. I will be testing this tommorow at noon PST, as Friday is supposed to be 93 degrees and Saturday is only going to be 84. The nights are getting chillier here and I'd rather test it at 90 degrees plus, than 84 and it's going to be at least an hour and a half.

I will make stops at each 30 minute point, take the temp with the BK multimeter and pics. I am a pessimist about these things. Until I see it work, like it's really supposed to work, then I'm a doubter, even with my own work. I was encouraged by the 45 minutes I spent last weekend and now we'll see the results tommorow.

PS: I scored a 30' foot roll of 1/8" thick, highly dense fiberglass on Ebay yesterday. If tommorow's experiment works, then I'm planning on making up new pads, using 1/8" thick material for multiple pads and layers. Maybe up to 4 layers of fiberglass, laid up with 8 layers of Kapton! And it will be thinner than the two blankets I have going now.

http://www.ebay.com/itm/360723862891...ht_3094wt_1102

 

Update: Tested today. I took the '74 with the extra second blanket and took it out for a long desert drive. Work was slow and I had it ready to go, so I went for it. Ambient temps were in the high 80's, low 90's and went out for two hours. Drove up to Mojave CA and then turned around and headed back.

It took nearly an hour to reach max. temp today of about 119 to 120 degrees on the floorboard next to the gas pedal.



I drove barefoot the whole way, just to let the tootsies test out the area. It never got burning, blazing, gotta-get-outta-there hot, but it was never heat free either. I don't know if it ever will be! But we're working on it. I'm seeing a ten degree drop, but that's not enough. I want to see it closer to 100 degrees, like my Ford Focus, which would be tough, but I'd be OK with 110 degrees, considering what it is, versus the Focus



I'll call this 'inconclusive'. I'm not going to BS any of you and go rah-rah-rah, sis-boom-bah, no. You're gonna get my honest impressions. It wasn't bad, but it wasn't great either.

I think we can do better. I've got the roll of 1/8" thick, very dense fiberglass cloth coming in next Wednesday and I will be making up a multi-layer pad of at least 6 to 8 layers of fiberglass and Kapton Film. It won't be two separate pads either, with lightweight 'fluff' fiberglass. It's going to be one pad and a lot of dense layers (like the astronaut suits) and then, I'll hope for one more hot weekend this year to really test it out.

If I have to, I WILL be trying different materials, processes or whatever. I've got other ideas I'm exploring too, that have been kindly suggested by other forum members, including the guy who started this thread, Adam (thanks!, I'm looking into it!).

 

Earlier, tested the handheld IR gun against the BK, 123 vs 122.8! Just got back from a good litte run, let sit in the shop for 30 minutes. Popped the hood and just for giggles , shot the temp on the windshield wiper motor...beep, 155 degrees and deeply imbedded in the firewall, the coil was 153, and this after 30 minutes...

Shot the inside, corner of the gas pedal 111 and as I moved the gun up, the temp increased, 119, 125 and stopped at 134 degrees. It's not just the exhaust, it's that powerplant, with the heads an inch away! God, I was looking at Four Channel Thermocouple recorders or better yet, how about a IR image or map of the dash, cowl, floors, engine compartment so you get a picture of where exactly all this heat is eminating from and why.

As I drove back earlier, I thought of how hot the pedals are, so I leaned over and started reaching up and feeling up the dash, grabbing the upper brake pedal and surprised at how hot it was. Even the parking brake release handle and the cable behind it, was hot. And both of those are nowhere near the exhaust system. The brake pedal, hanging there off the mid to top part of the cowl.

 

I have a 68 bb and until I fixed the trans tunnel and floor with reflextic and the tunnel foam and sealed all the holes in the firewall the heat in my car was melting. I mean my wife and I drove 51miles one way in Aug. in Texas {102} and by the time we got home when she got out of the car and went to take off her flipflops the shoe on the left foot in a small spot was stuck to her foot. Melted, not all the way but wrinkled. So now after the reflextic and foam its very nice. I still need to put on some good hedders and that will make it even better. Try it.

 

Wow... that's bad. Is the reflextic on the inside? And I wonder too, if the close fitting factory exh manifolds put some distance from everything else,.versus the headers. I think you have a lot less radiating surface area too, with a straight drop down and out versus the thin wall, long tube headers, that too are a larger diameter as well.

That would be an interesting side-by-side IR signature pic, that's for sure. You might just better keeping the factory manifolds, just sayin.

 

I remembered something I read about headers, in David Lewis's "Chevy Small Block Interchange Manual" so I found the passage about them in the exhaust manifold section, and besides rusting out and scraping on the ground, they create excess engine compartment heat too. Makes sense now.

Looking at the shield covering the front lower and angled floorbord tonight, I can see where I could easily add a good five inches more upwards on the drivers side, nearly to the bottom of the steering column. Ditto for the passenger side as well. There's a lot of uncovered area too, up in the outside corner of the fender.

 

I have stock manifolds on my car along with sidepipes. Compared to a stock, under-car, exhaust, my pipes are quite far from the firewall. My car is no less hot though...my wife and I rarely drive it over 40 - 50 miles one way as it becomes unbearable. Quite a shame really.

I have read that an extraordinary amount of heat comes through the seams in the area behind the passenger side vent door behind the kick panel. I do agree that the engine heat seems to come right through the firewall though. Another thing I noted during one of our more brutal excursions, was that opening the car up, with windows down and t-tops off, the heat seemed to be even more intense which makes me think that the negative air pressure in the cockpit is actually sucking the heat from the engine compartment into the car. It would be interesting to do a comparison of the temperature increase after an hour drive in a closed up car versus wide open...starting from stone cold.

I still maintain that we should be working on them in the summer and driving them all winter...a perfect cold weather car!

John