Bulletproof cooling system

400 small block chevys are a special case. The cylinder barrels are siamezed in the block so that no cooling water can pass between them. This creates hot spots or "steam pockets" in the block at lower engine rpm's which conceivably could create a spot at the top of the cylinder that is hot enough to create pre-ignition. As rpm's increase, there is enough turbulence in the cooling system to wash these steam pockets away. GM engineers cured the problem by drilling holes into the cylinder heads to relieve this pressure and allow water to flow from the block up into the heads. That's all fine and dandy if you are using a 400 head on a 400 block because the heads are drilled. But, when using any other kind of head on the 400 block, there are usually no steam holes in the heads unless you are buying new heads and specify to the manufacturer of the heads that you want steam holes drilled into them before delivery. Alternately, if you already have the heads, you can have your machine shop drill the holes or you can drill them yourself if you have proper equipment.

400 small block chevys are a special case. The cylinder barrels are siamezed in the block so that no cooling water can pass between them. This creates hot spots or "steam pockets" in the block at lower engine rpm's which conceivably could create a spot at the top of the cylinder that is hot enough to create pre-ignition. As rpm's increase, there is enough turbulence in the cooling system to wash these steam pockets away. GM engineers cured the problem by drilling holes into the cylinder heads to relieve this pressure and allow water to flow from the block up into the heads. That's all fine and dandy if you are using a 400 head on a 400 block because the heads are drilled. But, when using any other kind of head on the 400 block, there are usually no steam holes in the heads unless you are buying new heads and specify to the manufacturer of the heads that you want steam holes drilled into them before delivery. Alternately, if you already have the heads, you can have your machine shop drill the holes or you can drill them yourself if you have proper equipment.

http://www.gregsengine.com/350to400.htm

http://www.gregsengine.com/350to400.htm

==Swapping a core support and matching radiator into a recipient vehicle==

==Swapping a core support and matching radiator into a recipient vehicle==

==Serpentine cross-flow radiators==

==Serpentine cross-flow radiators==

Most cars from 1960 and up used cross flow radiators. One of the reasons was a lower stance of the overall automobile, two, the vehicles were getting wider and more cooling area was required to cool the larger engines. Cross flow rads had a tank with an inlet/outlet placed on either side. The water entered on one side and passed through the core of the rad, was cooled by the air flow and the heat escaped through convection to the outside air. Engineers found that the longer the liquid was exposed to the cooling flow of air through the rad core, more heat could be extracted from the flowing water. They slowed down the water travel by increasing the size of the water pump pulleys, but that had its limitations. They also added more rows of core, but that too had limitations. Road course racers in 1969, found a way to keep cooling to a simple easy form. To do this, they pulled the tanks off the rads that they were using and placed baffle plates in the tank covers. The baffles were placed so as to divide the rad core section into three distinct areas. Water would enter the upper rad inlet on the right side and would flow across the top section of the rad to the left side, a baffle plate located 2/3rds of the way down the tank caused the coolant to flow across the rad to the right side to the right rad tank. The coolant, couldn't rise upwards because a baffle plate located a 1/3rd of the way down stopped it and forced it to head down lower in the right tank, where it again was drawn across the rad core to the lower left tank outlet and out to the engine. This serpentine course that the coolant took, allowed the coolant to be cooled THREE TIMES by the cooling air flow coming through the core area. Excellent idea!, you say, why don't they do that to all cars today? In a closed course atmosphere, the theory works, but in real everyday life the average auto would never warm up to operating temperature during the daily commute. That's why ONLY HOT RODDERS are privileged to use this system.

Most cars from 1960 and up used cross flow radiators. One of the reasons was a lower stance of the overall automobile, two, the vehicles were getting wider and more cooling area was required to cool the larger engines. Cross flow rads had a tank with an inlet/outlet placed on either side. The water entered on one side and passed through the core of the rad, was cooled by the air flow and the heat escaped through convection to the outside air. Engineers found that the longer the liquid was exposed to the cooling flow of air through the rad core, more heat could be extracted from the flowing water. They slowed down the water travel by increasing the size of the water pump pulleys, but that had its limitations. They also added more rows of core, but that too had limitations. Road course racers in 1969, found a way to keep cooling to a simple easy form. To do this, they pulled the tanks off the rads that they were using and placed baffle plates in the tank covers. The baffles were placed so as to divide the rad core section into three distinct areas. Water would enter the upper rad inlet on the right side and would flow across the top section of the rad to the left side, a baffle plate located 2/3rds of the way down the tank caused the coolant to flow across the rad to the right side to the right rad tank. The coolant, couldn't rise upwards because a baffle plate located a 1/3rd of the way down stopped it and forced it to head down lower in the right tank, where it again was drawn across the rad core to the lower left tank outlet and out to the engine. This serpentine course that the coolant took, allowed the coolant to be cooled THREE TIMES by the cooling air flow coming through the core area. Excellent idea!, you say, why don't they do that to all cars today? In a closed course atmosphere, the theory works, but in real everyday life the average auto would never warm up to operating temperature during the daily commute. That's why ONLY HOT RODDERS are privileged to use this system.