Conversion - Radiator and Fan

I originally hoped that with the LT1 Opti-Spark distributor on the front of the engine rather than the back of the manifold, I could mount the motor further back and get more clearance for the radiator and electric fans. This proved not to be the case. With the Monza mounts in the stock location, I still needed to ding the firewall on the lower left side by the transmission tunnel to get some relief for the left head and block. Clearance in front is critical! With no mechanical fan on the water pump, you must run an electric fan. The more efficient set-up for electric fans is a "puller" rather than a pusher. I wanted to run a 2-row aluminum radiator to reduce weight and optimize cooling during the West Texas summers. I elected to get a 26x16 Be Cool radiator modified for the LT1 reverse flow cooling system. The problem is you can’t fit the radiator and electric fans behind the core support. You either have to sacrifice some cooling efficiency by running a pusher fan in front of the core support and radiator behind it, or you have to put the radiator in front of the core support and a puller fan behind it. Tony elected to take latter approach using a single 16" electric flex fan without a shroud behind the core support with the radiator in front. I am using shrouded dual 11" SPAL fans rewired as pushers in front of the radiator to move 2750 CFM. A B&M transmission cooler sits between the radiator and the water pump cover. I also converted from the stock 180 degree to a 160-degree thermostat; the fans are set to come on at 190 degrees. The core support is modified and a new "box" surrounds the radiator and fans to minimize airflow loss due to the pusher setup. There are some relief holes in the fan shroud to prevent blocking air at high speed. This also requires modifying the brace that ties the header panel to the upper and lower core support that normally goes around the condenser on an A/C car. Since the radiator cap will not be accessible under the header panel I am using a remote fill setup from a ’92 Corvette LT1. This consists of a pressurized surge tank that connects between the radiator, engine, and heater core, with a tap line to return cylinder head coolant to the system. The radiator cap is on the surge tank. By locating this on top of the inside right fender, it ensures any air pockets in the system are continually purged and eliminates hot spots in the head an block. For a complete description of the LT1 reverse flow cooling system, see the article on LT1 cooling attached below.

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