keeping the heat out

[John Morralee]

It was a hot/hot evening and we ( 5 other healeys ) had been fighting stop/go traffic for the last 30 mins. Keeping the heat out was the subject. One car owner said he had installed baffles around the exhaust pipes where they leave the engine and pass under the unfortunate driver, as I look at my BJ7 with an eye to installing same it does not appear apparent to me that this would be benificial . Has anyone done same or similar?

 

[Dave Russell]

Hi John,
There is little doubt that the cars get very hot inside. Some folks go to great lengths to improve on the original minimal heat barriers.

There are some very hot parts just on the other side of the firewall & floor. Fixes include additional heat barriers of various materials & constructions. These are applied to the outside, inside, or both of the cockpit surfaces. They all reduce the inside heat, some, remarkably well.

The sources of heat are both radiant & conducted. The baffles you mention could well reduce radient heating.

I hesitate to make a specific recommendation because everyone seems to have their own favorite methods & materials. A search of this website should turn up a lot on the subject.
D

 

[GregW]

Hi John,
I’m not sure how the baffles would work any better than the stock heat shields, then again I guess it could be a crafty design. Quite a few have installed heat shielding under the carpet. Some use the aluminum faced bubble wrap and others (myself included) put Dynamat Extreme down. Be warned, Dynamat ain’t particularly cheat. Here is what it looks like.

 

[AUSMHLY]

I too used Dynamat Extreme. Over that I replaced the jute with Low-e insulation. Consider the trans tunnel too. The bottom I used Pegasus heat shield and over the top I used Low-e. I also removed the heat shields under the car and glued the Pegasus under them, then reinstalled the heat sheilds.

There are threads on this site all about what members had done. Thanks to those here who help me.

click on attachment for the photo of the Dyamate/low-e inside the car. Other two photos will be a part of this post.

Cheers, Roger

 

[Randy Harris]

Yikes, Roger. That's so pretty I think I'd drive the car without carpet!

Randy

 

[judow]

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I've just 'adjusted' to Agatha and her 'hot' personality. I grin and bear it during the summer and for the rest of the year am glad for the 'heat.'

Good luck with all the solutions.

P.S. My right foot once heated to the nth level becomes numb to the sensation.

 

[suprgnat]

Hi John,
... and others (myself included) put Dynamat Extreme down. Be warned, Dynamat ain’t particularly cheat.

Not to resurrect a dead thread, but for a less expensive alternative to Dynamat try B-Quiet Ultimate:

https://www.b-quiet.com/ultimate.html

$129.00 for 50 sq. ft. ($2.58/sq. ft) vs $270.00 (list) for 36 sq. ft. of Dynamat Xtreme ($7.50 sq. ft.).

The specs are virtually identical.
B-Quiet Ultimate:
Acoustic Loss Factor ASTM E756 @ 200 Hz:
0.23 @ +0C (+32F)
0.26 @ +10C (+50F)
0.39 @ +20C (+68F)
0.32 @ +30C (+86F)
0.24 @ +40C (+104F)

Dynamat Xtreme:
Acoustic Loss Factor @ Temperature
(Using ASTM method E756 @ 200 Hz):
0.081 @ +14°F (-10°C)
0.240 @ +32°F (+0°C)
0.257 @ +50°F (+10°C)
0.417 @ +68°F (+20°C)
0.259 @ +86°F (+30°C)
0.194 @ +104°F (+40°C)
0.140 @ +122°F (+50°C)
0.094 @ +140°F (+60°C)

Dynamat is slightly better at lower temps and B-Quiet is slightly better at higher temps, at least in terms of the Acoustic Loss Factor. For all I know, It's just a statistical error and they both source from the same factory!

Installation wise, if "Dynamat" wasn't emblazoned all over their products, you'd never know the difference. I've used both, but only used the Dynamat because I ran out of B-Quiet and could get the Dynamat 4 sq. ft. Wedge Pack for the princely sum of $40.00 ($10.00/sq. ft.!!!) from the local Best Buy.

Paul

 

[Cutlass]

B-quite looks good, but what are the thermal properties?

 

[suprgnat]

Their listed withstand temperature range:

Temperature Range:
-60C to +155C (-76F to +311F)

(cut a pasted from their site)

 

[Cutlass]

I understand that, but what are the insulating properties of the material?

 

[Dave Russell]

These products were intended to be sound insulators. Any heat insulation benefit is a by-product, thus not usually specified.

We "could" assume that the heat insulating properties are similar/proportional to the acoustic loss specs. Maybe yes, maybe no.

In the real world, Dynamat Xtreme has proven to be a quite good heat insulator. In my opinion, it's exceptional adhesive qualities allow it to be tightly rolled down over clean surfaces with no fear that water will ever get under it to cause rust. The Dynamat was overpainted body color & nearly invisible.

I've found that two layers provide a lot of heat blocking & take up little space. No doubt there are cheaper ways to go & likely just as good.
Pics attached.
D