View Full Version : Looks like I'll be building the Midget LE

03-28-2010, 07:34 PM
Long story short, I've had it w/ rostyles and want to go w/ Challengers (when I can afford them). While I'm at it, might as well build the Midget that never was. I figure a LE Midget should have Challengers, at least a 3.55 and a/c. Yes, I said it, air conditioning. Kelly wants a/c and I like to give my wife what she wants.

A conventional auto a/c system doesn't make sense for one of these, so I was thinking of running a unit powered off of an inverter. NO, not a window unit! Of course I would have to change the alternator.

I was thinking about taking the componants out of a dorm size fridge and building a custom unit that would either fit in the glove box area, in the radio console ( move radio to rear panel or in trunk w/ remote) or putting it in the trunk and have it blow through the rear panel. I've also been thinking of mounting an evaporator in the heater core box and using those vents.

Does anyone foresee any problem with w/ using this type of system (dorm fridge) in a moble application w/ an inverter? (ie, compressor gulping oil). Any other ideas? ( gas fridge from an RV or a 12 volt unit from something else?)

I need a new dash anyway, so I might experiment with B vents in the Midget dash.

BTW, NO OVERDRIVE or five speed !!! I will not cut this car! (O.K, I'll drill a hole or two for a/c, but that's it and I don't mind a rear end swap.)

Hopefully this will be the first of many posts on this subject. Project will progress as funds allow. I don't foresee ever getting a V8B or a Sebring nosed Sprite, so I might as well have the only Midget LE. From what folks say I've got a really solid car, so I might as well. She deserves it and my wife does too. <<GRAEMLIN_URL>>/grin.gif

03-28-2010, 08:27 PM
That should be something. I always thought they should have made an LE, or something similar.

03-28-2010, 10:09 PM
Go for it! Make it what you want it to be.

03-28-2010, 10:25 PM
Yes, I said it, air conditioning. Kelly wants a/c and I like to give my wife what she wants.

You do know that the top folds down right? Search some old threads and I think you'll find that Midgets are convertibles. :devilgrin:

seriously, why reinvent the wheel, there are neat electric AC units for the Hot Rod market. I just pulled this website out of a magazine. www.southernrods.com (https://www.southernrods.com) you might also find something for a boat.

03-29-2010, 08:55 AM
Didn't know about that JP, thanks! Gotta have a/c down here in 110% humidity and 95*.

03-29-2010, 09:49 AM
Rather than use a 110 volt ref. unit, I would ditch the inverter and use a ref. that is wired for 12V, like the RV people use. Maybe mount it all in the truck, but have the ducts mounted over the tunnel to bring the air forward.
Good luck,
Scott in CA

03-29-2010, 11:00 AM
I'd rather go 12v if avalible. I didn't know if they had them or not.

03-29-2010, 11:15 AM
I have long been flirting with the idea of making an AC/heating unit of peltier coolers.


03-29-2010, 11:32 AM
I have long been flirting with the idea of making an AC/heating unit of peltier coolers.

https://www.virtualvillage.com/400w-12v-thermoelectric-cooler-peltier-plate-001540-017.html That's just brilliant. I never knew stuff like this existed. Are you thinking along the lines of putting several of them right in the heater box, in a baffle sort of arrangement, with a drip trap and drain?

Using the center console might work as a separate unit...Make grilles for the radio and speaker holes; radio inlet, speaker exhaust; fan behind the speaker, drain thru the trans tunnel. Hmm...

What would the current drain on these things be? I assume our little Lucas alts couldn't keep up?

03-29-2010, 11:57 AM
I have a 78 amp GM alternator, so I got room to spare. The plate in my link draws a little over 3 amps. I was thinking three of them would be required to achieve any real cooling. In my fantasy plan, I would make a custom box to mount them in that would replace the stock box. Heat sinks would be mounted on each side of the coolers, one on the inside of the box, one on the outside. In this way, the cool side is in the box, while the hot side vents to the engine compartment. Or reverse the polarity and you have a heater with the cold side venting into the engine compartment.

I guess you could make a box that mounts inside and come up with a coolant pump system to remove the hot/cold from the cockpit. Hmmm... that is actually a pretty good idea.

03-29-2010, 04:37 PM
JP, I followed that link but can't find any 12v only stuff that doesn't use a belt driven comp.

03-29-2010, 06:37 PM
Okay, you've got me thinkin' about this now...I've been brainstorming ideas about using three peltiers in the center console.


You would build a little cool box out of 1/4" Foamcore. The peltiers would be mounted vertically with 1" finned heatsinks on each side. The hot side could have a surgical tubing arrangement in the fins. A little pump would circulate the coolant out the firewall and back in. The cold side would have a foamcore baffle to force all the incoming air, through the radio hole and over the fins. A little 3" fan (like the cheapo "personal cooling fans" from Wal-Mart) would be supported under the speaker hole. The foamcore would be cut around the fan like a shroud. The existing wiring harness and stuff would all be outside the cold box.

There'll have to be some provision to deal with the condensation, and it may be better to keep the fan motor out of the airstream somehow.

Come to think of it, it may be better to run the whole thing in reverse: since the cold dense air would flow down and out naturally, the fan wouldn't have to work nearly as hard. Of course, then you'd basically just be cooling off the shift boot. :smile:

Food for thought, anyway!

03-29-2010, 06:52 PM
In 2005 I remember reading that a couple of teenagers had built an automotive AC using the peltier devices. They won an award for developing Freon-less AC. Read an article about them here. (https://www.treehugger.com/files/2005/07/teens_invent_fr.php) At the time it was a big deal and I haven't really heard anything further about it until now.

I know I have played with Peltier devices before like at the local Oregon Museum of Science and Industry (OMSI) and the amount of heating and cooling put off by these devices seemed very small though intense but with little convection/radiation. It almost seems like you would have to mount them to a water jacket to get a direct conduction transfer of energy (heat or cool) and then circulate the conditioned water past a fan. Just blowing air across the top of a Peltier chip doesn't seem like it would be too effective though. Whatever the case, I'm surprise that there really hasn't been any developments in this field (especially considering that the Peltier effect was discovered in 1834! It seems like it would be low maintenance and long lifespan. Oh, and according to the article, even recyclable!


03-29-2010, 06:55 PM
JP, I followed that link but can't find any 12v only stuff that doesn't use a belt driven comp.

this seems pricey compared to their ads but it is one of them

https://www.southernrods.com/categories/h...oduct-1978.html (https://www.southernrods.com/categories/heating-and-cooling/heating-and-cooling-systems/products/product-1978.html)

03-29-2010, 07:08 PM
This is probably what you're talking about:

https://www.southernrods.com/categories/h...product-11.html (https://www.southernrods.com/categories/heating-and-cooling/heating-and-cooling-systems/products/product-11.html)

Doesn't seem bad to me and should (hopefully) be able to replace the heater box under the hood and blow through those vents. You could use the ducting to direct the air up under the dash and blow in your face. I'd pay $400 for that. That might just be the ticket. Thanks JP!

03-29-2010, 10:13 PM
that's the one, glad you found it. Please Please document this - pics and explanations. This is new territory and worth remembering.

03-29-2010, 10:23 PM
It'll be a little while,. Gotta get some cake first.