Has the efficiency of automotive ac units improved to the point where a porsche 912 small 4 cyl. can be air conditioned without overloading/overheating the engine? If so, who manufactures the best unit? Thanks.

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- Nick

Nick you would be better 912 forums .

Seems to me there was an outfit in San Antonio that had a kit they would put in old bugs and what not. I would say no, an air conditioner on a 4 cylinder air cooled motor is not a good idea.

The Sanden rotary compressors use a lot less power than the old York single-piston thumpers. They're at least worth looking into.

--DD

I can attest that a 1200 cc 1965 Bug ran fine with an AC system, it was a dealer option that used an old style less efficient York Compressor, and ran all the time in the Arizona desert. It did not over heat the engine, although you did want to switch it off on step grades as it did drain some power, but you didn't notice it most of the time, only on step hills. it made the car icy cold.

The AC was an option on 914 cars with the type IV motor, not sure if it caused problems or not, but I doubt it. This is same style of motor as the 912E cars.

Some 356's have run old school AC systems installed, I have seen them in 356 Registry magazines. I don't recall mention of over heating issues in them, you may want to inquire on the 356 registry form if you have that style of motor in your 912.

I say go for it if you want, for me I prefer the windows down and where applicable wing windows full open approach to climate control. But you should be able to run the AC without over heating the motor, it is no big deal. It only draws a small fraction of the available horsepower.

The 914's air conditioning was installed at the dealer, or after the sale. None of the series-production 914s had air conditioning fitted at the factory.

Not really relevant to this discussion, but I did want to get it out there.

The 914's A/C install involved cutting up the engine tin, which allowed the cooling fan to re-ingest already-heated air for cooling. This could be a problem, especially when the car was sitting still. The same compressor setup in the 912E placed the compressor above the engine tin, so no cutting was needed.

If you can keep from cutting up the engine tin, your engine will be happier in hot weather.

--DD

I know the original poster was talking about a 912, but since this is started in the 914 section........

I had an A/C 914 once. It worked fine. Remember: The 914 interior space is small so there is not a lot of work for the compressor to do on a constant basis. Mine would cut out the compressor when the interior temp reached where I had set it, but I never really noticed it cutting in and out.

Please note that the condenser has to go into the floor of the front trunk. A hole is cut in the floor, the condenser is laid flat over the hole, and a fan is placed on top of the condenser in order to blow the heat away. The entire thing is covered with a box like cover and in theory it is watertight.

But it does hog up a lot of the front trunk. The evaporator, the unit inside the car, run along under the dash and is sort of noisy, but the real drawback to it is if you have a console you will need to remove it and cut down the part next to the dash since the A/C vents run through that area. The best way I have found to deal with this is to buy an A/C console from someone, install it, and then sell the non A/C console I had to remove. This sure beats trying to cut up your console and make it look right.

The units installed in US cars were all made close to Fort Worth, Texas, and were then dealer installed. There were aftermarket units as well. ARA made a good one.

And changing the compressor drive belt is an adventure in itself. Install the best belt money can buy as changing the belt is a pretty big deal.