Should I use jute or heat insulation below carpet?

[Jon #40768]

I am installing a new interior in a 67 big block coupe and would like to know if I should use jute or a heat insulator only, or install both. The side exhaust heats up my feet. I am worried that using both the jute and the insulation will be to thick.

Who makes a good insulation?

Thank you
Jon

[Mike M.]

Re: Should I use jute or heat insulation below car

jute and insulation together will disallow good fit of carpets. use the foil-faced insulation and your feet will love ya. mike

[Lee S.]

Re: Should I use jute or heat insulation below car

Use the absolute best material you can find. I have a C3 with a big block. Those 2.5" exhaust pipes running down the center of the car are hot. Here are some suggestions...

http://www.heatshieldproducts.com/index.htm

http://www.coolandquiet.com/products.cfm

I used Reflectex from Lowes. Home Depot now carries it. It worked a lot better that the standard jute backing. At some point (after flight judging), I'm going to add one of the above products (Zero Clearance) under the car and under the carpet again.

C3's have some unique issues that may not apply to your car. You may consider a hot water shut off valve to the heater core.

Between the above fixes and getting my AC operational, I cruise in cool comfort.

Again, I stress, put in the best insulation available.

[Jack H.]

Re: Should I use jute or heat insulation below car

The book 'Corvette Air Conditioning Strategies' documents the benefit of modern foil vs. jute insulation. Also, shows that MUCH of the cockpit heat is NOT the result of exhaust rather the reflection of heat radiated from the road pavement surface.

On car's that are A/C equipped, owner/operator 'cockpit' training can go a long way to reducing the 'hot Corvette' syndrome.... Point is, the hot water valve shutoff valve is only active when A/C is set to MAX and makeup air is being recirculated vs. fresh exterior sourced via the cowl. Regardless of A/C setting, when you shut the engine down for a short period (lunch break, fuel stop, grocery store run, Etc.), you lose vac and the hot water valve opens.

By fluid convection, hot engine warmed coolant migrates to the heater core and the inside of your Harrison air box gets hot. If it doesn't seal FULLY (few did), when you restart the car and drive off, ram induced flow from the cowl through the air box will 'trickle' warm air at you.

Solution: when you restart and drive off, run the A/C in MAX mode for a few minutes to 'suck' residual heat out of the heater core. Complaints of 'hot' cockpit should fall dramatically with this proceedure....

Back to foil vs. jute.... Remember, when/if the car is being Flight Judged, savvy interior judges are going to do due diligence to verify factory authenticity. Expect them to lift the carpet where it's free to move (at the front 'flaps' covering the seat rails, at the junction of the floor and the rear compartment upright member). They expect to see jute vs. bright/shiney aluminum foil!

[Michael S.]

Re: Should I use jute or heat insulation below car

The best product "I" have found is called "Dynamat". It can be purchased in a box containing 36 square feet for about $100. Not cheap but VERY good. Sound, heat, cold, road noise etc. Highly recommended by high end car audio people. It is very thin at less than 1/4 inch. Sticks like nobodies business and in form fitting to the floorboard/firewall. Just installed in a 67 convertible. Carpet fits superb and results are amazing.

I previously used the old bubble pac foil product. HUGE difference. This product IS worth the expense in a Corvette. It takes 2 boxes to do a coupe/convertible car correctly including the roof (coupe) and behind the door panels.

Mike
#11202

[Jon #40768]

Re: Thank you all very much. You have helped a lot *NM*

[John H.]

Re: Should I use jute or heat insulation below car

I agree - I used Dynamat to completely line the interior of the Cobras and the Grand Sport I built, to dampen panel drumming and reduce heat transfer, and it's extremely effective stuff. Scan below shows it being installed in one of the Cobras; conforms to any contour, and a heat gun activates the adhesive. I added foil-faced material on the Cobras - their cockpit heat issues make a C3 seem like a modern car

[Jon #40768]

Re: Should I use jute or heat insulation below car

Thank you very much. Where can I get the Danamat and the fiber reinforcing? What type of reinforcing? Is the foil faced material a form of Danamat?

Thank you again
Jon

[John H.]

Re: Should I use jute or heat insulation below car

Last time I did this was in 1996; since then, Dynamat has a new product that incorporates the foil facing on the original damping material so only one application is required (instead of two layers). Eastwood sells some Dynamat products, and a Google search should show their distributors.

Cobras are a bear for heat due to the sweep-out of the headers being about 2" from the front of the footboxes; I covered the footboxes, dash, and tunnel with Thermo-Tec, then fabricated .062" aluminum panels to completely cover those areas as well. Lots of tedious work, but it really killed the radiated heat problem that plagues Cobras. Did the same thing on the Grand Sport, minus the aluminum panels.

[Jon #40768]

Re: I used to work with two men from shelby

I used to work for Ryan Falconer Racing engines. The owner, Ryan used to run the 289 program at Shelby and Owned a real GT 40 years and years ago that he sold for $8,500. The partner Jack, used to run the trans-am mustange program. Jack had a Shelby mustang and was offered one of the daytona coups when Shelby closed down, but declined as ex race cars were not worth anything. Oh-well.

Ryan was also an original owner of a big tank midyear fual car.

Thank you again for your help
Jon