The original Heating Solution No. 999 published in 1980, and No. 999 revisited in 1981, 1983 and 1984, have assisted dozens of Tiger owners in the U.S. and Canada resolve their overheating problems. Here is the latest information on what some call the “INDIANA CORE.”
Increased cooling with the “INDIANA CORE” is provided by the use of small scoops or louvers cut into the fins between each radiator tube. These louvers force the air to circulate inside the radiator a longer period of time, allowing it to remain in contact with the fins longer and exchanging more heat. This louvered design is now used by all radiator manufacturers in custom cores. One of the concepts in core design is the use of staggered tubes. Instead of having three, four, or five tubes running across the radiator one in back of the other, they staggered the tubes front to back each slightly below the one in front. This allows for more tubes per inch of depth and, in turn, more water volume and flow.
The cores mentioned in this article are manufactured by Mangum and are available throughout the U. S. The Mangum core uses 1/2″ tubes on 5/8″ centers. Your stock Tiger core is 18 5/8″ high, 15 1/2″ wide and 1 3/4″ deep. The replacement R series core in the stock dimensions is a three tube design with 11 continuous fins per inch. The tank plates are 2 1/8″. Experience has shown that the replacement of your stock core with the stock dimension Indiana Core could give you 5-10 degrees improvement. For those who need additional cooling, the next available step is to a 2 3/8″ core. This core has four tubes for an even greater capacity and additional flow. The tank plates are 2 1/2″. This radiator should handle the majority of street Tigers short of all-out extreme racing conditions. Installation of this core should not require modification to the radiator bulkhead. The brackets on the radiator are set 3/8″ to the rear from the stock location to allow for the radiator to fit deeper into the bulkhead. This fitting allows for fan to radiator and radiator to rack and pinion clearance.
ARADAC core is now available from North Side Radiators. This core is 2 1/8″ deep with 4, 1/2″ tubes on 1/2″ centers. It provides the same amount of flow as the 2 3/8″ Mangum core but in a shallower package, for those of you who want a very stock appearance. The cost is a considerable increase over the Mangum, but if originality is a concern, it is an alternative. This radiator was installed in the Harrington-bodied Sunbeam Tiger with excellent results. The custom radiator people at North Side Radiator are familiar with the Tiger radiator and the cores available. When shipping your radiator, include your name, address, phone, and the core size, and 11 louvered continuous fins per inch. Turn-around time has been running about two weeks. The price is still reasonable, and the service quality. One of the biggest advantages of this modification is that it is a tum key setup. The radiator comes to you ready to install.
Don’t hesitate to call me with questions or problems. Barry Schonberger