Early SPF GT AC Vent Mod

[Lynn Miner]

On the early SPF GT40's, the fresh air vent to the cabin and air conditioning is left open. The problem that stems from this is that hot air coming off the radiator has a tendency to get “picked up” by this vent and sent into the cabin defeating the purpose of a vent and making the AC work that much harder. On later cars (I'm not sure what serial number dealt with this), the vent is actually plumbed into the scoops on the hood. This solves the inducted heat problem but provides a direct path for water ingestion into the vent system during a ride in the rain. Either way this modification provides a way to get cooler and drier air into the vents on the early cars.

The materials used in this modification are available from Eagle Tool Co. These parts are used for industrial woodworking vacuum systems but work perfectly in this application. Start with a 3 inch male to male coupler as shown below.
On one end, “grind” off a portion of the coupler as shown. This is done using a disk or belt sander and is done to facilitate the installation of the coupler into the tapered and beveled hole in the vent.
Dry fit the coupler into the hole as shown. Cut the coupler as required to get a snug fit. Now apply a liberal amount of black RTV silicone sealant to the inside of the hole.

Put the coupler in the hole and uniformly spread black RTV all the way around the coupler and allow to cure over night before proceeding. While the RTV is curing, cut a length of 3 inch ribbed vacuum hose (also from Eagle).
The length of this hose needs to be approximately 26 inches. Cut it to your particular requirement. After the RTV is cured, fasten the hose to the coupler with a hose clamp and curl the hose down and behind the windshield washer tank. Using two large tie wraps, tie the hose to the tank. The vent pickup will now get fresh air closer to the road surface well away from the radiator and not be subject to water being injected into the system