BritishV8 Forum

General Category => MG Sports Cars => Topic started by: BlownMGB-V8 on July 21, 2016, 06:12:03 PM

Title: A/C
Post by: BlownMGB-V8 on July 21, 2016, 06:12:03 PM
Here's the basis for my future A/C system for the MGB:
IMG_0035.JPG
It is the evaporator out of a VW Vanogen

Here it is in place in a '74-1/2, not the car it is to be used in but a good test for fit.
IMG_0031.JPG

It is positioned above the cowl vent door but the wiper mechanism and windshield vents may pose a challenge
IMG_0032.JPG

The dashboard will have to be positioned closer to the driver.
IMG_0033.JPG

I won't be able to start on this for awhile, but I bought these parts so I can run the under-hood lines back to the firewall.

Jim
Title: Re: A/C
Post by: rficalora on July 24, 2016, 03:16:21 PM
Looks really big.  What size condensor goes with it?
Title: Re: A/C
Post by: MG four six eight on July 24, 2016, 05:02:57 PM
Holly crap Jim, are you looking to freeze steaks in that thing!!!
One of the biggest challenges will be to find space for all of the plumbing and wiring, but I'm sure you'll be able to figure it out no prob!

If I can ever get around to restoring my C-GT, I would like to add A/C and electric power steering to it.

Bill
Title: Re: A/C
Post by: BlownMGB-V8 on July 24, 2016, 05:26:46 PM
I think the condenser is about 28 x 16" and around 7/8" thick. The pump is a large displacement Sanden. Evap should be big enough not to freeze up I hope. Got a 2 ton TXV on it.

Well you know, it is a convertible after all. Takes a lot of capacity to A/C the outdoors. But I do have some experience, I once worked in a hot shop in the summer where I took a room A/C unit, mounted it on a cart, rolled it up to my work station and plugged it in. Got a few funny looks for that one but I really didn't care.

Jim
Title: Re: A/C
Post by: Charles on July 26, 2016, 10:50:29 PM
Jim, have you explored mounting the evap. in the trunk and running duct to the front, or maybe using two (2) evaps. one for each side. The controls for two evaps already in use on today cars.

charles
Title: Re: A/C
Post by: MGBV8 on July 26, 2016, 10:51:57 PM
That is so cool that the ChumpCar is getting A/C!
Title: Re: A/C
Post by: DiDueColpi on July 26, 2016, 11:12:18 PM
Agreed Carl, but mounted on the hood like that it's only going to benefit the guy behind him!
On the other hand it's big enough that I should be able to feel it up here.

Live like you mean it.
Fred
Title: Re: A/C
Post by: BlownMGB-V8 on July 26, 2016, 11:40:15 PM
No, no no. You guys have got it all wrong. Didn't I say it was for my roadster? Not the Chump car. Not the trunk. Not the hood. Sheesh, you bunch are hopeless. Bunch a senile old...

Look it's very simple. Maximum overkill in the allowable space. Simply yank out the dash, throw all that away and there's plenty of room for A/C. What could be easier?

Jim
Title: Re: A/C
Post by: Nexxussian on July 27, 2016, 01:56:55 AM
No, no no. You guys have got it all wrong. Didn't I say it was for my roadster? Not the Chump car. Not the trunk. Not the hood. Sheesh, you bunch are hopeless. Bunch a senile old...

 Look it's very simple. Maximum overkill in the allowable space. Simply yank out the dash, throw all that away and there's plenty of room for A/C. What could be easier?

 Jim

:D
Title: Re: A/C
Post by: MGBV8 on July 27, 2016, 09:16:21 AM
I see what car it is mounted in.  ;)
Title: Re: A/C
Post by: BlownMGB-V8 on July 27, 2016, 09:57:30 AM
No! That was just for the picture! It can't go in the Chump car, that would just slow it down! In fact we should probably get rid of some weight. Do we really need that part of the body? We'll have a cage right? Maybe we can just chop out that part and toss it. And all that bodywork on the off side of the car, what's any of that doing for us? We can throw away that too, right?

Jim
Title: Re: A/C
Post by: MGBV8 on July 27, 2016, 02:40:58 PM
It would speed it up with all that cool air blasting towards the back of the car!
Title: Re: A/C
Post by: Dan B on July 27, 2016, 06:45:35 PM
Looks pretty cool!
Title: Re: A/C
Post by: Khan on August 04, 2016, 05:19:04 AM
very nice in golf country
Title: Re: A/C
Post by: BlownMGB-V8 on August 04, 2016, 10:26:14 AM
Well, the under-hood work is complete. The suction run was kept short outside but will cross the dash inside where the more heat it absorbs the better.
IMG_0001.JPG
adequate pulley clearance was found by using a "reduced diameter" hose for the high pressure line
IMG_0002.JPG
The dryer was tucked in tightly against the liquid separator for the intercooler system.
IMG_0003.JPG
And the liquid line was kept short inside but is run low outside where the more heat it sheds the better.
IMG_0005.JPG

The evaporator and dash will be a winter project, and maybe not this winter either. Lots of planning is required for that one.

Jim
Title: Re: A/C
Post by: rficalora on August 06, 2016, 01:49:50 PM
Looking good Jim.  Others may have different experience, but I've found AC to be useless with the soft top.  So much hot air pours in around the door glass that on a 95-100° day, the cockpit is still in the upper 80's whenever I'm going about 25-30 mph or higher.  That's why I got a hard top for the heat of the summer around here... But, I find I prefer the top down and only use the AC & hard top when my wife is with me.
Title: Re: A/C
Post by: BlownMGB-V8 on August 06, 2016, 05:07:11 PM
All I want is a big vent that blows cold air in my face.

Jim
Title: Re: A/C
Post by: Charles on August 08, 2016, 09:56:01 PM
Jim, Rob  agree cooling a soft top like ours is like running a warm morning stove inside the frig. Both work real hard and get very little done.

Like Jim wrote, all I want is a cool breeze in my face and maybe in the foot wells.
Title: Re: A/C
Post by: MGBV8 on August 09, 2016, 08:44:50 AM
And maybe a vent aimed up your cargo shorts.  ;)
Title: Re: A/C
Post by: pcmenten on August 09, 2016, 12:15:37 PM
Does it need to be in the dash? Can you run the lines behind the seats and mount it in back?
Title: Re: A/C
Post by: pcmenten on August 09, 2016, 12:15:37 PM
Does it need to be in the dash? Can you run the lines behind the seats and mount it in back?
Title: Re: A/C
Post by: BlownMGB-V8 on August 09, 2016, 01:37:06 PM
Wouldn't have to be but it might be a little hard to get the cold air where you want it that way, and gives up trunk space.

I'm pretty sure the dash can be moved rearward enough to allow the use of the existing gages which would be good, although they might have to be moved around a bit, and the stereo equalizer needs to be a shallow design. The glove box will also need to be redone and quite shallow. but possibly wider. There is time for the design to evolve.

Jim
Title: Re: A/C
Post by: danmas on August 09, 2016, 02:58:59 PM
Quoteall I want is a cool breeze in my face and maybe in the foot wells.

Mine has a floor vent that blows directly on my feet. Priceless.
Title: Re: A/C
Post by: waterbucket on August 11, 2016, 01:53:20 PM
This may be of interest to those who need a compact air con and heater unit, I found it while browsing Ebay. I know nothing of the company although it is based only thirty miles from where I live, British made with Spal fan so it could be good. Two links below for info;

http://www.ebay.co.uk/itm/NEW-Air-Conditioning-Unit-Kit-for-Auto-Car-Motorhome-Cabin-Marine-Camper-/190867525448?hash=item2c70974f48:g:xGcAAOxycSdR2yee


http://www.t7design.co.uk/index.php/air-conditioning/air-conditioning-units/aircon-heater-combination-unit.html

Philip
Title: Re: A/C
Post by: Russ Bellinis on October 15, 2016, 08:44:17 PM
You don't want too big an a/c system for your car.  Bigger is not better!  I am a retired transport refrigeration mechanic.  I also worked on Carrier bus units.  If your system is too big, the evaporator will get too cold and make ice.  There is no defrost system on an a/c unit, so when it ices up, it stops air flow over the evap and makes more ice, which stops air flow even more and makes more ice.  The only way to defrost the evap is to shut off the a/c unit until the ice melts and then turn it on again for however long it will cool before icing up again.  The worst case scenario is that the evap ices up, the refrigerant can't evaporate in the evaporator, and ends up liquid slugging the compressor.  Now you need a new compressor and a complete system clean out.

The Vanagon evaporator is designed to cool a van.  If the interior of your car is smaller than a Vanagon, the evaporator will be massively oversized.  If your car is a relatively small two seat sports car, look for a evaporator from a small standard cab pick up like Chevy S-10, Ford Ranger, or Toyota or Nissan, or even a Dodge Dakota with the standard cab.
Title: Re: A/C
Post by: BlownMGB-V8 on October 15, 2016, 10:43:45 PM
Thanks for the insight. However, the cabin of a convertible is infinitely large with the top down, so maybe bigger could be better after all. Long as there is enough airflow to keep the evaporator above freezing, Ice shouldn't be too much of a problem. Massive volumes of 40 degree air sounds just about right to me!

Jim