Bobby's father, Robert Clark,...
Bobby's father, Robert Clark, welds up the brackets for the new radiator mount.
When the water/coolant moves across the radiator one time, it is called a "single pass" radiator. Obviously when the water flows across one set of tubes and then comes back across a second set, you have a "double pass." The second set of tubes is placed right behind the first, which makes the radiator a two-row core or dual core. Now you can have a dual core single-pass radiator or a dual core double-pass radiator.
While you can also purchase three- and four-row core radiators, they are not a good alternative for Saturday night racing. The more rows of cooling tubes stacked one behind another, the harder it is for the air to get through, which is a key to cooling. A Sprint Cup car running 200 mph at Daytona would have no problem pushing air through a three- or four-core radiator but that's not the case in our project Dirt Late Model. Dual core is the way to go. The only question we had to answer was single or double pass.
While many pit experts think that double pass is the way to go, much of that decision rests with your particular motor combination, where you run, length of race, etc. Also important is the past history. Our DLM has spent all its life in Florida and has always run the current motor with a dual core single-pass radiator never once experiencing an overheating problem. In fact, the engine has never seen the "danger zone" of 220-plus degrees even in the longer features. Dual core, single pass has worked fine for us in the past and it should in the future.
The additional length on these...
The additional length on these brackets will help stabilize our new radiator.
As this story is being written, our engine is sitting over at Southern Style Racing Engines in Pinellas Park, Florida, getting a refreshing by master engine builder George Pils. While this process will be featured in another CT story, it is relative to this article. The motor is being cleaned and serviced. But the only raceday change we are making is a new Quick Fuel carburetor. Everything else is staying the same...for now.
While discussing radiator options with George, he made the very valid point that the motor only has to push he water through a single-pass radiator one time. In a double-pass radiator you've essentially got that water coming and going and something (horsepower) has to help it move. Our goal is to maximize the horsepower and torque of this engine, so we want to spend as little horsepower as necessary on ancillary things like pushing water through a double-pass radiator. Therefore, we settled on a dual core single-pass radiator from C&R Racing. Keep in mind that this philosophy works because we already know that our present engine package successfully ran multiple years with a dual core single-pass setup.
This all-aluminum radiator uses hand formed tanks with an aluminum billet neck and 1 1/2-inch inlet and 1 3/4-inch outlet. The radiator is heliarc welded with two row furnace brazed cores. C&R does not use epoxy which reduces the efficiency of the radiator thanks to its insulating properties. The factory core mounts will allow us to easily install the radiator.
When we moved the radiator...
When we moved the radiator mounting points forward we made sure that the new location would clear the hood, using the pins and a straight bar as a guide.
Our new C&R radiator is slightly larger than our old one, so we'll have to fabricate a new housing and mounts for it. We used aluminum diamond plate because, frankly, it looks cool. After fabricating the housing we took an 8 inch by 3 inch piece of flat aluminum plate and formed two brackets that wrap around the tubular frame. On one side of each bracket we put a 90 degree bend that will allow the bracket to continue for another two inches. This gives added support to the radiator housing and once the whole unit is in place and bolted together the radiator will not move.
We moved the radiator from its original location forward by one inch and up by one inch in order to give some additional clearance between the steering rack and the bottom of the radiator. When we did this we were careful to take into account the line of the hood, note the location of the pins in the top picture.