A/C and heater in my V8

[914GT]

Currently I'm installing heat and air conditioning in my V8 914. This is my project while I'm off work for a couple weeks for the holidays. If anyone is interested in seeing progress photos I'll post some. I'm already well into the project but I've taken several pictures as I've been going along.

[914fan]

yes. post pics. they could be usefull to all of us that want ac and or heat reguardless of engine type.
Thank you

[914GT]

Here's a picture of the heater assembly I'm using. This is a copper/brass core, approx. 6"x 8" x 2-1/2", mounted in a steel box with a single air inlet on one side and dual outlets on the other. This one was built by David at Desert Hybrids here in Tucson. Since he already had a nice powdercoated box and core put together, I decided to buy it from him rather than taking time to fabricate one myself. I don't know the exact core he used, but it looks very similar to Nissan p/n 27141-01P00 used in the 80's 300ZX. Here I have soldered on the copper tubing and fittings for connecting the hoses.

[914GT]

The heater box connects to a stock 914 heater blower. I mounted two dropping resistors inside the heater box to provide three blower speeds for the stock blower motor.

[914GT]

Here are the two dropping resistors for the blower motor. You can buy resistor networks specifically for this purpose, but since I'm 'cheap' and had these 50W resistors in my parts box I decided to use what I had on hand.

[914GT]

At the top of this picture is the heater control valve used to control the coolant through the core. Since I no longer have the stock 914 fresh air box, I used the original dash control for the fresh air blower to control the heater. Sliding the control to the right opens the valve, and at the same time selects the blower speeds.

That's all for now. I'll post a few more later.

[sean_V8_914]

guy, you always do nice work.

[914GT]

Here's the heater box and blower installed in the car.

[914GT]

Parallel flow condenser mounted on radiator support.

[914GT]

Drier with binary safety switch and high-side port mounted on trunk wall. I'll explain the hose routing later.

[914GT]

The high-side liquid #6 barrier hose off the drier drops to the bottom of the trunk and loops around along the radiator support. From there it enters through the opening where my radiator hoses go through. But once inside the hose pops up under the gas tank before crossing over into the cabin.



In the above picture you can also see a new wiring harness utilizing the grommet for the old return fuel line. Several wires are bundled inside to run the relays in the radiator fan shroud and the compressor clutch control.

Once inside the car, the high side hose from the drier comes out right at the expansion valve.

[Amark]

Nice job Guy. It was 27 degrees when I took the kids to school this morning. Heat is good.

[914GT]

Originally posted by sean_V8_914
guy, you always do nice work.

Hi Sean.... thanks for the compliment. When are you making another trip to Green Valley, AZ?

[914GT]

Originally posted by Amark
Nice job Guy. It was 27 degrees when I took the kids to school this morning. Heat is good.

I've been getting along without heat but that's because I normally keep it inside the garage. If it's stayed outside overnight then forget it. Too cold for me!

[914GT]

Here's where I 'deviated' from the normal method of running the hoses behind the rocker panels. I routed the A/C and heater hoses inside the longitudinals through the stock heater pipes. I cut access openings on the top of the longs next to the wheelwells in order to remove the old 'J' stovepipes. The metal pipes have too sharp of a bend to route and insert hoses through them. There is also a plastic fitting on the pipe which narrows-down the opening, so that was removed too. The new hoses run inside the fiberglass insulated pipes except for a foot or so toward the front. I wrap the exposed sections of the heater hoses and the A/C suction hose (returning from the evaporator) with Armaflex insulation wrap. This will reduce unwanted heat radiation into the car, and prevent any condensation. Condensation is not normally much of a problem on rubber barrier hoses anyway, expecially in Tucson.



Above is the #10 suction-side hose from the evaporator routing across under the dash and into the long to go back to the compressor. Also is the #8 discharge-side hose from the compressor going up to the condenser. I found a boxed-channel under the gas tank that allowed the hose to make a direct shot into the front trunk area.

Once I'm done I'll cover the access openings with new steel covers. I'm debating whether to screw them in or spot weld them in a few places.

[914GT]

Here's how the A/C hoses enter the engine bay. I use a rubber PVC pipe cap with two holes punched in it to match the diameters of the hoses. You can see it in this picture behind all the wiring I have not cleaned up yet.

[914GT]

Mounted on the engine is a Sanden SD5H14 compressor. Everything on this car including the compressor is designed for HC134a so *hopefully* it will cool things down quite nice. I allowed ample hose for a service loop to provide plenty of clearance from the exhaust, and allow easy removal of the compressor from the engine if I ever need to drop the motor.

[914GT]

On the heater side, I built a 'manifold' out of 3/4" copper fittings to interface the two hoses to the heater core on one side, and the engine on the other side. On the engine side, one hose goes up to port on the intake manifold next to the thermostat. The other hose goes into the suction side of the electric water pump. The crossover pipe has a 1/4" diameter restriction inside. This provides a bypass for the water pump when the engine thermostat is closed. The bypass prevents water pump cavitation and improves cooling by allowing coolant to circulate the engine block during warm-up. For the hell of it I powdercoated the piece cause I haven't powdercoated anything for a long time.

[914GT]

Work under the front hood is about done and ready to button up. A/C system has been evacuated and holds vacuum, but I'll hold off charging it for a while yet. The engine cooling system and heater core has been pressure tested to 15 psi to check for leaks. Lots more to do inside the car, including installation of some new gauges, new speaker installation, dash improvements, and removal of center console.

[3D914]

Guy,

I've been outta touch for a while. Looks like you've been keeping busy - and doing a great job at it I might say.

Did you ever sell the red V8?

Take care,