Keeping Your Cool in a Tiger

An Article by Dan Walters
September, 2001

Page 2

The Straight Skinny:

.... There are two sources of top radiator hose filters that I know of. The oldest source is GANO filter at (415) 968-7017. They have a variety of different hose sizes with a standard configuration of a clear plastic tube with two screens. The first screen has a small hole in the middle to pass coolant and debris to the second screen. The duel screen system seems to work well with the first screen plugging and causing the coolant temp to go up as a sign of filter plugging. However, the restricted filter can cause the top hose to blow off or rupture! You have to keep on top of the maintenance of a GANO filter! There is a brass tube available as an option or as a replacement for the crack-prone plastic tube.

....The other source is good old J.C. Whitney (312) 431-6102. They also have different hose sizes available in plastic or aluminum. One major drawback to their filter is that once plugged, there is a by-pass that lets debris go to the radiator and renders the filter useless.

....Cooling system filters have been available for years but have not received much publicity. It seems there are two schools of thought among people aware of cooling system filters. One group uses them routinely. The other group thinks they are unnecessary or not worth the hassle. The biggest problem with the cooling system filter is that the more it is needed, the more maintenance is required. High efficiency radiators tend to have smaller tubes that are easily plugged by debris circulating in the cooling system. It's a simple case of choosing which you would rather clean, the radiator or a filter. The CAT parts dept. is looking into stocking the GANO filter.

The Nitty-Gritty

....The original Tiger radiator has a core 15 1/2 inches high, 18 1/2 inches long and 1 3/4 inches thick. It has 31 columns of 2 rows of tubes and 30 columns of 1 row of tubes in a staggered 3 row configuration for a total of 92 tubes at 1/2 inch spacing. It has continuous vertical fins at a rate of 13 fins per inch. It has a design that even after 30 years is considered to be heavy duty and still available. However, it is usually one of the first things to go when trying to make a Tiger run cooler. I started off giving the specs for reference to what is original and to give a baseline for use in comparing other radiators.

....In the past (even now) the typical replacement radiator was a FAT CORE 4 row that was too thick to use with the original fan shroud and 4 blade rigid fan (that you wanted to replace with a "better" flex-fan anyway). It may have 31 columns of 4 rows in a in-line configuration for a total of 124 tubes at 1/2 inch spacing. It was 2 3/8 to 2 5/8 inches thick and had fan-fold fins at a rate of 12-14 fins per inch. It worked better but you paid the price in space and sacrificed the fan shroud and fan clearance. This radiator would not be considered to be a "high efficienty" radiator by today's standards.

Today's Story

....The typical high efficienty radiator of today has tubes that are spaced on 3/8 inch centerlines and have fins at a rate of 16-18 fins per inch. A typical Tiger radiator would have 35 columns of 4 rows with a total of 140 tubes and a core thickness of 2 3/16 inches. You could easily use the original fan shroud (if you have it) and virtually any fan of the proper diameter. If you want to get carried away you could step up to 5 rows with a total of 175 tubes and a core thickness of 2 5/8 inches!