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MG MGB GT V8 Factory Originals Technical - A/C in a GTV8
|Can anyone recommend a specific A/C unit to fit in a BGTV8 (standard setup, with Rover motor)? I realize that cooling must be fully up to nick to even consider A/C. As I understand it, one will need a generic condensor and dryer, a bracket for the compressor (anyone know where to get one?), a Sanden compressor and the blower/evap unit. My understanding is that there are some units on the market that replace the heater, in addition to serving as the A/C evaporator. I looked at the www.hotrodair.com site and the www.vintageair.com site but it's not exactly clear to me what you'd want to use or where they intend for you to mount these things. Do these units go essentially where the heater box is located at the rear of the engine bay?|
Next question: why do folks say that you must move the motor rearward (the "A/C motor mount" issue) in order to install a system? Is this simply because of the need for the condensor in front of the rad? If so, can't you just use a condensor that goes from the top of the rad a foot or so down to the big horizontal panel -- I mean, there's an inch or two behind the shut panel that you could easily use for a condensor. I can't see going through the calisthenics that would be necessary to move the motor back -- everything that is so carefully orchestrated would, I think, be thrown out of whack.
As far as the interior blower vents, I assume you can just use the face-level vents in the middle of the dash for the A/C output. (If I have any choice, I don't want to go down the road of those old dealer-installed systems that you sometimes found in BGTs; they take up much too much room in the passenger footwell.)
Any comments appreciated.
I am not a specialist on AC but i do know that these days there are also compressors which are driven by an electromotor. These can be fitted more or less everywhere. You only may need to upgrade your alternator.
|Peter van de Velde|
Malcolm Gammons may still have a few of the RV8 ac kits for sale. They fit a Rover engine fitted with a 1970s/80s timing cover (plenty about ) and provide an evaporator in the passenger footwell which feed the faschia vents on the dash.
The footwell is quite constrained by the additional kit- any fuel injection / additional kit may have to be resited but that end works on a RHD car - you might have to modify for LHD. Remember too that the RV8 has exhaust manifolds that exit through holes in the inner wings - the RV8 aircon pipes run under these. You would need a different run with blockhuggers.
Peter's advice is also worth following up because the RV8 compressor fit is very tight and there is enough space beside the battery box for the right electric motor. In principle it would be better not to clutter up an already tight engine bay.
Keep us posted.
|Peter's post gives me a killer idea -- if there _is_ an electric compressor on the market, as Roger suggests, one could install it in the unused battery box ... and then install the evaporator in the GT's spare wheel well (for years I've just run with a couple of cans of Tyre-Weld -- and gotten no flats -- so no need to carry a spare). You could run cold air up through the rear deck!! -- no need to finagle under the dash etc. The only trick, it seems to me, would be to figure out what to do for a condensor and dryer. Flat under the car with a fan? Any ideas?|
|I wonder if Rover Group ever tested the A/C equipped RV8s under arduous conditions like Arizona or the Sacramento Valley in the summer!|
The cooling system on a Factory GT V-8 is so marginal that I cannot imagine an A/C system that you could use at any ambient temperature over 80 degrees, which effectively limits its usefulness. The problem is getting hot air out of the engine bay. A conventional A/C unit with the condenser in front of the radiator will pre-heat the incoming air. The additional pump and plumbing will further serve to clutter the engine bay and allow less air movement.
The use of an electrically driven A/C pump is a good one - I think Geo (Suzuki?) or Mitsubishi used a unit like this. One suggestion is to also relocate the condenser and its cooling fan(s) to an area away from the engine bay, a la Opel GT.
Check with D & D in Detroit. Dan carries the brackets to mount a RV4 type compressor. It's short and looks like it will fit well. I've heard others onthe BB say it works and it's cheap!
The electric driven compressor has been a standard on aircraft for many years. (you don't want to pay the price) . They work well with the air flow the aircraft puts to them but are not practical automotive use. Lower speeds, ie traffic lights, translates in to very high pressures that would stall the electric motor.
As far as the under car condenser, how many times have you raked the exhaust on a speed bump?
I've used the under vehicle setup in many different cars/trucks before and it works well, if you have the clearance.
Good engine cooling and a lot of air flow are the keys if you want a good A/C system. The more condenser the better.
|Terrence before you throw out Peter's idea about an electic compressor (remember 30 amps will only provide half a Kilowatt of cooling) you might still put the condensor at the front of the car under the main radiator where the UK vehicles have their oil cooler.|
The long run to the battery box area would still work -there is no obvious reason for any of the kit to ground (yes CB heights have a more general clearance problem).
However - if you have the right timing cover (the RV8 cover is NLA) you could still use the mechanical compressor and put an evaporator behind your chair !
Otherwise bake....like the rest of us !
|Yes, the AC motor mounts designed and sold be Glenn Towery set the motor back an inch and a half for the purpose of gaining space for the condenser.|
The units I saw from VintageAir place the evaporator/blower unit in the passenger side rather than replace the heater.
I bought a system from a junked MGB that came with the dealer installed AC. I didnít buy the compressor because it didnít look like it would fit in an MGB V8. The condenser is only about ten inches tall and mounts in front of the radiator with the stock electric fans adjusted forward and no need to set anything back. The drawback is that a small condenser cannot release as much heat.
The evaporator/blower unit is in the passenger side as are most post factory systems, but it far forward and not in the way. There are two black plastic panels that go below the dash and follow the curve up the sides that house the vents and controls.
On most factory AC installations, the incoming air is cooled as it passes through the evaporator and if it is too cold, it is re-warmed as it passes through the heater before being routed through the vents to the occupants. The ďmaxĒ setting switches the air source from external air to recycled cockpit air. The dealer unit always uses cockpit air and doesnít re-warm air, but rather has a thermostat to cycle the compressor off.
I bought a compressor mounting kit from D&D Fabrications that mounts the old style long compressor alongside the left valve cover. I had to modify the inner wing to fit. Itís nice to know they now offer a new one for a shorter compressor. Iíll have to check on that.
After all that, I havenít installed the whole thing because I can barely keep the thing from overheating without adding the additional stress of AC.
The biggest problem with using an electric powered compressor, would be that you canít drive very far with yanking the power cord out of the wall :-)
|I used to have a Volkswagon that had AC. The condensor units were under the car and cooled by small electric fans. Ground clearance was not a problem. However, it was a 69 air cooled engine and when the compressor kicked in the speed would decrease by about 15 mph. The AC was on the car when I got it and was a dealer unit.|
I just stumbled upon Jim Stuart
|I messed up that link, try this one.|
|Terrance, you might want to give Glenn Towery a call. He has done a number of V-8 conversions with A/C and dosn't have a problem with the engine overheating unless it is a real scorcher of a day. (95 degrees and up) and even then the engine only runs hot if you are stuck in traffic. Glenn has all the parts you need for sale and can be reached at (302)734-1243. e-mail firstname.lastname@example.org|
|Guppy has described the conditions that are normal in the Sacramento Valley from July through September - 95 degrees plus and traffic.|
My Factory V-8 overheats under those conditions even without A/C!
|Paul, I assume your car is basically done? is there a picture of it somewhere online? My car is pretty stock-looking and I think looks basically like a factory model from the outside, but I'd like to see a picture of the real thing. (I'm sorry that you have to live with that stock cooling system though, it must be a little touch-and-go.)|
|Paul, something is not set up right wilh your V-8. I have a 3500 that I used to pull a 3,000 lbs. trailer ( for 6 years) & I was stuck in 106 deg heat for 6 hrs. My 4200 has air & I am going to put shrouds on all the fans & it will stop the heat problem I am having with her. If I were to put the shrouds on my 4.9 , that has no A/C, I would not worry about her getting hot on a 100 deg. day. It is all in the air that HAS to go through the rad., the rad. & the fans. & the pressure cap. Tha more air the better the rad can cool. The better the rad. to transfer the water heat to the rad. fins the better it will cool. I run the L.E. spoyler on my cars to force more air through the lower valance. I have a scoop from the valance to the rad. that make ALL the air go through the rad. I plug the holes on thr rad. suport plates, to make all the air go through the raid. I use the 80 stock colling fan switch to turn on the 2 stock elect. fans. I use this switch for it turns on at 200 deg. & alu. motors need 190-195 thermostats for the motor to make power & get better fule milage. What I do when I get everything right with the system I will let it run till the fans kick on thin I mark on the temp. gauge were the fan came on at ( all gauges vary) I use the Tr-7 13 blade water pump fan on the water pump on my cars with an adp. plate I have spent thousands of dollars in 18 years to try to get a better rad. than the TRUE made in england factory rad. In 600,000 miles I have never over heated! when the M.G. is set up right|
|Man, the linked a/c looked like a LOT of work for a/c in a late model B! The dealer installed a/c are not bad enough to make me want to cut up my firewall for a/c!|
That linked site was not the dealer-installed air. I just included it because Terrence wanted to see how Vintage Air does it and how it ties into the heater system. The dealer-installed system only requires two holes about an inch in diameter through the firewall for the hoses.
This thread was discussed between 15/08/2001 and 29/08/2001
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