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MG MGA - Cockpit Heat
|The comment about Transmission tunnel heat reminded me of something I have been intending to post about.|
When discussing cockpit heat we hear about insulating the fire wall a great deal. If I were to prioritize the sources of heat into the cockpit I would list.
1. the entry holes in the firewall
2. radiant heat from the exhaust pipe under the floor board
3. radiant heat from the firewall
4. radiant heat from the transmission tunnel.
No one ever seems to comment on #2. I have carpet insulation under my carpet on the floor board but I'm here to tell you that sucker just radiates heat anyway.
I just went out about bought a 5 foot long sheet of 16 gauge aluminum. I'm going to mount studs along the bottom of the floorboard along the length of the exhaust and put the aluminum on there as a heat shield. I'll leave a 1/2" or so gap between the aluminum and the floor board for air circulation.
I'll report back. Anybody have any comments or experience with this?
|Don't forget the gaps between the firewall and the body skin. Usually largest in the upper corners behind the dash. e.g. upwards and outwards from the bonnet opening handle between the reinforcing rib and the skin. I had a veritable hurricane of hot smelly air through small gaps there.|
|It may just be easier to mount the aluminum shield to the exhaust pipe using regular exhaust clamps. Point the screw ends upwards and mount the aluminum on top of the flat side of the clamp. I've never done this but it sounds pretty easy (if you say it fast). And you don't have to remove any carpeting.|
|I'm planning to use Dynamat type insulation under the carpet and fire wall etc. How well does this work and will it cope with exhaust heat?|
|I found cookie baking sheets that were two layers with an air gap between the layers. It took three sheets to do it, but they cover the whole floor board area. I left an half inch gap between the sheets and the floor so air can pass over the sheets as I drive down the highway. One might say that I am three sheets to the wind.|
|S E Bryan|
What is wrong with the "heat shield" that I see sold in Moss and other sources? It seems to be designed for the purpose and should have a better result than cookie sheets? Cheers!
|I've just finished restoring my A coupe and took every measure I could to reduce the heat and noise. I did everything from 1 thru 4 and them much more. I drove 150 miles last weekend in 75 df and it was cool and quiet. This weekend will be the real test when I attend a car show in Woodland Ca and it will be 105 df. I'll let you know how it goes. For the exhaust heat I installed 6" wide by 1/8" thick aluminum sheet bolted through the angle iron frame/floor. I turned the edges over to add stregth and stop vibrations. Works great so far.|
Andy 60 coupe
|I used Dynamat. It helped some, but still gets hot. I also used heat exhaust shields like T. McCarty talked about before that.|
|I'm very tempted to use Lizard skin ( a ceramic spray on heat and sound insulation) on my roadster. Id like to coat the inside of the transmission tunnel and not the out side of it (although I will probably use a carpet pad and carpet over it.) Dynamat also makes "Xtreme Dynamat" quiet and cool. Another very expensive product is koolmat some distributors actually have it custom fit for the MGA http://www.koolmat.com/main.htm I'm just not sure it's worth the cost. I have also purchased the Under dash pad set that was made for the Coupe offered by Moss .|
|What about using a header wrap on the exhaust pipe from the manifold to the muffler? I haven't tried it and don't know if there would be any problems in doing so. Anybody ever tried it or know of any reason why it wouldn't work? It seems that if it can block the heat radiating from the header it should be able to do the same to the exhaust pipe. The only draw back I have heard is that, over a long period of time it will deteriorate the header, and I would assume do the same to the exhaust pipe. Any thoughts?|
|The hard part about exhaust pipe wraps is if the exhaust does not get up to full heat (long drives) they will rust out, but they do work. Creating a "V" shaped aluminum heat shield and mounting it upside down above the pipe and muffler and keeping and air gap between the the pipe and the floors will dramatically reduce. I did this in a LR Defender 90 I used to own.|
|Just found this product |
Cool It Thermo Tec clamp on heat shield
| If its from JC Whitney, it probably saves gas, too! lol|
|I know JCW tends to carry a lot of Crap but Themotec's line of Coolit products are very legitimate I first purchased them through Jeggs and Summit racing http://www.thermotec.com/. I just purchased a 3 foot section to go over my exhaust pipe under the floor boards (it might take me until next summer to get her back on the road, but I'll report back on how or if it works)Also just noticed Moss sells an exhaust pipe heat shield #451-728|
|I installed a thin steel sheet under the toe board and floorboard, using nuts on the ends of the floor mounting bolts. The captive nuts in the floor frame acted as spacers.|
This has worked well in my 56 roadster so I will repeat it on my 58 coupe.
|OK I received a 3' test section of Thermo Tec Cool It Clamp On Heat Shield (on sale from JCW) did a mock up test fit. This is a straight forward great idea to be installed above exhaust pipes. The 3' section will cover the section under the seat floor boards, if you wanted to cover the entire pipe. A 2' section would bee needed under the smaller toe/ heal boards and a 2 foot section will take you from the muffler forward to the exhaust pipe clamp (keeping heat out of the battery tray area. This is the route I'm taking, now to find a good coating for inside the trans tunnel. Here are some photos (the last 4) of the mock up install. (no I will not be using zip ties when installed permanently.)|
This thread was discussed between 15/05/2009 and 09/06/2009
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