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Air Conditioning/Heat and keeping a working Cowl Vent
Part 1
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Air Conditioning/Heat
Mark wanted to retain the cowl vent and have ample cooling in the interior. A Supercooler from Vintage Air fit the bill.
The unit can be mounted as it comes with the center outlet under the dash. Mark chose to build some round vents into the dash, so the unit was temporarily positioned behind the dash to assess space available for hose and duct routing and vent locations.
The new center outlet was machined from some ABS plastic and modified OEM louvers. Vintage Air offers many sizes and styles of vents to suit your application. After the units position was determined some round stock pieces that were drilled and tapped were welded to the inside of the firewall to attach the mounting brackets to.
Once defroster duct locations were determined, holes were cut in the dash support and dashboard. Small pieces of double sided trim tape temporarily hold them in place. Tape will be applied to the entire mounting flange for final installation to seal it to the bottom of the dash support. Louvers in the garnish molding will direct air onto the windshield.
Holes were drilled in the firewall for bulkhead fittings to handle water and freon needs of the AC unit. A Vintage Air Proline Drier was also attached to the firewall. A hard stainless line was made up to connect the drier to the bulkhead fitting. Mark is using o-ring fittings for all the freon lines and AN fittings for the heater lines.
Under the dash things are definitely tight the higher you mount the AC unit. Make sure of your routing and rotation of fittings before having your lines crimped. A Trinary Safety Switch from Vintage Air was incorporated into the high pressure line behind the evaporator. The two AC lines run under the unit to the 90° bulkhead fittings, the heater lines run over and around the unit with the heater control valve squeezed in.
For the drain line Mark bent up some 3/8 stainless tubing and routed it thru the toeboard. A piece of 3/16 tubing was welded to it to connect to the cowl vent drain. Hose clamps will be added were needed on final assembly.
Tech Tips
* If your are limited on A/C evaporater space because of the stereo, check out our Step 13: Interior (Now in Stereo, almost!). It may make the differance on being able to use the next bigger size A/C unit!
A Working Cowl Vent???
A magazine recently showed how to flatten out the vent to use as a filler, because you'll never keep it working when you install an A/C unit.....Obviously, if you tell someone that it can't be done, someone will prove you wrong! This is something that you should take into consideration and lay-out when you lay-out the A/C unit and duct routing.
Mark decided to give up the windshield’s crank out feature in favor of cowl mounted wipers, providing a cleaner roof line. However, the crank mechanism was an ideal candidate to drive the cowl vent. The outer two arms were removed by drilling out the rivets, the remaining arms were then twisted about 40 degrees.
The lower portion of the cowl vent deflector was trimmed to provide more clearance around the defroster ducting. Two holes were then drilled in the hinge to accept 10-32 swaged rod ends. Two more were attached to the arms and connected with some 10-32 all-thread. The windshield mechanism has more than enough travel to drive the vent so Mark set his up that when open the arms are parallel to the cowl support. This minimizes the angles the linkage has to accommodate.
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Copyright © 1999-2009 Bob Shetrone