Bulletproof cooling system
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===400 SB Chevy engines=== | ===400 SB Chevy engines=== | ||
400 small block chevys are a special case. The cylinder barrels are siamesed 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. See: http://www.gregsengine.com/350to400.htm. | 400 small block chevys are a special case. The cylinder barrels are siamesed 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. See: http://www.gregsengine.com/350to400.htm. | ||
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| + | '''OIL COOLERS:''' Some cars will have the oil cooler installed in the radiator. In the writers opinion this is an extremely bad idea as (1) Regarding cooling, one has all ones eggs in one basket. (2) There is the risk of oil getting into the water or vice-versa. Note that an oil-to-air heat exchanger is extremely difficult to boil and it is a reliable method of getting rid of waste heat. | ||
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| + | Regarding combined coolers, allegedly a £57,000 German car uses a transmission cooler in the radiator for its fancy six speed gearbox. For some reason (allegedly the transmission fluid attacking the pipe) leaks occur. When this happens the pressurised engine coolant fills the gearbox which then explodes! The owner of the car has had this happen twice in two years and he describes the car as "Fifty seven thousand pounds-worth of c#@p" (however he needs it for his business). My own British made car has six heat exchangers and NONE of them are combined. This gives better reliability even though it is old and only cost about one percent of the price of the German limo. | ||
==See also== | ==See also== | ||
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