Bulletproof cooling system
From Crankshaft Coalition Wiki
(Add text, image, link) |
|||
| Line 1: | Line 1: | ||
| − | + | [[File:Engine-cooling-system.jpg|thumb|600px|right|Typical cooling system, some engines use an internal bypass]] | |
| − | + | ||
| − | [[ | + | |
==How the cooling system works== | ==How the cooling system works== | ||
| − | + | {{Note1}} All temperatures are in degrees Fahrenheit. | |
| + | |||
The cooling system works by absorbing, transporting, and dissipating heat. Therefore, anything that impedes any of those functions can cause overheating: | The cooling system works by absorbing, transporting, and dissipating heat. Therefore, anything that impedes any of those functions can cause overheating: | ||
| Line 32: | Line 31: | ||
*Defective radiator cap | *Defective radiator cap | ||
*Late ignition timing | *Late ignition timing | ||
| + | |||
| + | If the engine overheats when idling, typically the cause is a lack of air flow through the radiator. This can be from a missing of non effective shroud, a too-small fan or a defective fan clutch assembly. | ||
| + | |||
| + | If the engine overheats when cruising, typically this is caused by a too-small radiator/insufficient capacity or by the radiator tubes being occluded or too small. | ||
| + | |||
| + | Lowering the opening temperature of the thermostat is not the cure for these problems. Lowering the thermostat temperature rating only delays overheating. Do check to be sure the thermostat is opening, though. If the thermostat doesn't open, the engine WILL overheat regardless if it's idling or cruising. | ||
==Bulletproof cooling system tips== | ==Bulletproof cooling system tips== | ||
| Line 38: | Line 43: | ||
*Oftentimes, the cheapest and most bulletproof way is to use the largest radiator that will fit, along with the fan type and size, and shroud that was designed for the radiator from the factory. | *Oftentimes, the cheapest and most bulletproof way is to use the largest radiator that will fit, along with the fan type and size, and shroud that was designed for the radiator from the factory. | ||
*Use a full shroud, with the radiator positioned so that the fan blades are half-in and half-out of the shroud hole, and no more than 1" of clearance between the shroud and the fan blade tips (just enough to prevent interference when the motor rocks on its rubber mounts). | *Use a full shroud, with the radiator positioned so that the fan blades are half-in and half-out of the shroud hole, and no more than 1" of clearance between the shroud and the fan blade tips (just enough to prevent interference when the motor rocks on its rubber mounts). | ||
| + | [[File:Thermo fan clutch.jpg|thumb|210px|Typical thermostatically controlled fan clutch]] | ||
*Fan recommendations: OEM 18 inch, 7-blade steel fan with 2" to 2-3/4" pitch. The pitch of a fan can be measured by laying the fan down on a flat surface and measuring from the flat surface to the edge of the fan blade. Fans that are relatively flat (such as a flex fan) may not move enough air at idle and low engine RPM to cool the engine properly. | *Fan recommendations: OEM 18 inch, 7-blade steel fan with 2" to 2-3/4" pitch. The pitch of a fan can be measured by laying the fan down on a flat surface and measuring from the flat surface to the edge of the fan blade. Fans that are relatively flat (such as a flex fan) may not move enough air at idle and low engine RPM to cool the engine properly. | ||
| − | *When possible, use a thermostatically controlled fan clutch. While a thermostatically modulated fan clutch is an effective means of operating the cooling system's fan, a worn or defective fan clutch can cause overheating if left undiagnosed. Sometimes they may appear to be OK when cold but they will free-wheel when hot. | + | *When possible, use a thermostatically controlled fan clutch. While a thermostatically modulated fan clutch is an effective means of operating the cooling system's fan, a worn or defective fan clutch can cause overheating if left undiagnosed. Sometimes they may appear to be OK when cold but they will free-wheel when hot. <br style="clear:both"/> |
*Water pump and crankshaft pulleys sized according to what was on the engine from the factory. On a street motor, shoot for 1.2 to 1.3 times crank speed for pump pulley speed. This is usually true until you get to 3.55 gears and numerically higher, then 1:1 works better. Most 1960s muscle cars are 1:1. Sustained pump speeds over 4200 rpm can cause cavitation. Race vehicles may use a 2.3:1 ratio for a 9000-plus rpm engine. | *Water pump and crankshaft pulleys sized according to what was on the engine from the factory. On a street motor, shoot for 1.2 to 1.3 times crank speed for pump pulley speed. This is usually true until you get to 3.55 gears and numerically higher, then 1:1 works better. Most 1960s muscle cars are 1:1. Sustained pump speeds over 4200 rpm can cause cavitation. Race vehicles may use a 2.3:1 ratio for a 9000-plus rpm engine. | ||
*On a carburetor-equipped engine, often a 180º thermostat is used, although a little hotter thermostat rating (190º-195º) may make the motor more responsive and add a little fuel mileage. It may also help to burn off some of the by-products of combustion, such as moisture and acids which form and get into the oil. Motors using EFI induction should use the thermostat temperature specified by the factory for that particular motor to prevent false input to the computer and consequent problems. The sensor pill goes toward the motor. | *On a carburetor-equipped engine, often a 180º thermostat is used, although a little hotter thermostat rating (190º-195º) may make the motor more responsive and add a little fuel mileage. It may also help to burn off some of the by-products of combustion, such as moisture and acids which form and get into the oil. Motors using EFI induction should use the thermostat temperature specified by the factory for that particular motor to prevent false input to the computer and consequent problems. The sensor pill goes toward the motor. | ||
| Line 46: | Line 52: | ||
*Ensure that there is adequate airflow from the engine compartment to allow the exit of the air drawn into the compartment. In custom applications this might require the removal or surgery of inner fender panels or using spacers to raise the hood of the car up an inch or two at the back. | *Ensure that there is adequate airflow from the engine compartment to allow the exit of the air drawn into the compartment. In custom applications this might require the removal or surgery of inner fender panels or using spacers to raise the hood of the car up an inch or two at the back. | ||
*Maintain the proper coolant/water mix to prevent freezing up in winter. Water transfers heat better than coolant, but some coolant must be used to prevent freezing. Using a 50/50 mix of coolant/water is a necessity for motors using aluminum parts. Plain water will turn aluminum into oatmeal. | *Maintain the proper coolant/water mix to prevent freezing up in winter. Water transfers heat better than coolant, but some coolant must be used to prevent freezing. Using a 50/50 mix of coolant/water is a necessity for motors using aluminum parts. Plain water will turn aluminum into oatmeal. | ||
| − | *Before installing the water pump, grasp the impeller with one hand and the drive hub with the other and twist to make sure the impeller is tight on the drive shaft. | + | *Before installing the water pump, grasp the impeller with one hand and the drive hub with the other and twist to make sure the impeller is tight on the drive shaft. If the driveshaft is not spinning the impeller, no water is being moved through the motor. This problem can be the source of great frustration and is hard to find unless you know to look for it when installing the pump. |
*Although it may not be necessary, the concept of a "water pump conversion disc" can be researched. Flow Kooler originally marketed flat aluminum discs to be riveted to the backside of the stamped steel impeller of the water pump. With an iron impeller, a steel disc could be welded or brazed onto the impeller. Such a disc wouldn't be that difficult to make. Space the water pump backing plate back farther with a couple of gaskets to prevent interference of the rivet heads on the backing plate if riveting a disc to a stamped steel impeller. More info: [http://www.smokstak.com/forum/showthread.php?t=11774 brazing cast iron], [http://store.summitracing.com/partdetail.asp?part=BRA%2D4375%2D07&autoview=sku Flow Kooler water pump conversion discs]. This disc could make an appreciable difference in the flow of water at engine speeds under 3,000 RPM. On the other hand, Howard Stewart of Stewart Components (the guy with the water pump dyno), says that these discs have little to no effect. | *Although it may not be necessary, the concept of a "water pump conversion disc" can be researched. Flow Kooler originally marketed flat aluminum discs to be riveted to the backside of the stamped steel impeller of the water pump. With an iron impeller, a steel disc could be welded or brazed onto the impeller. Such a disc wouldn't be that difficult to make. Space the water pump backing plate back farther with a couple of gaskets to prevent interference of the rivet heads on the backing plate if riveting a disc to a stamped steel impeller. More info: [http://www.smokstak.com/forum/showthread.php?t=11774 brazing cast iron], [http://store.summitracing.com/partdetail.asp?part=BRA%2D4375%2D07&autoview=sku Flow Kooler water pump conversion discs]. This disc could make an appreciable difference in the flow of water at engine speeds under 3,000 RPM. On the other hand, Howard Stewart of Stewart Components (the guy with the water pump dyno), says that these discs have little to no effect. | ||
| + | **[http://www.FlowKooler.com FlowKooler]established a new standard for hi flow water pumps in 2013 with the release of a full line of precision machined billet impeller. The impellers have larger diameters and additional vanes and by reducing the clearance between impeller vanes mating surface create an appreciable improvement in flow rate and block pressure. This pressure increase helps prevent formation of steam pockets and hot spots on the cylinder wall and can also prevent cavitation of the impeller. | ||
==Swapping a core support and matching radiator into a recipient vehicle== | ==Swapping a core support and matching radiator into a recipient vehicle== | ||
| + | There are times when it may be easier, cheaper, or just better to swap in a radiator assembly from a donor vehicle to get better cooling, instead of buying a new radiator, etc. | ||
| + | |||
In doing this swap, you will have to re-install the recipient vehicle's hood latch onto the donor core support in the proper location. Make up a fixture beforehand from scrap metal that bolts to the fender bolts or some other location that will be the same after the core support swap, and will show the proper location for the latch. This is a must-do when doing a frame or clip swap. | In doing this swap, you will have to re-install the recipient vehicle's hood latch onto the donor core support in the proper location. Make up a fixture beforehand from scrap metal that bolts to the fender bolts or some other location that will be the same after the core support swap, and will show the proper location for the latch. This is a must-do when doing a frame or clip swap. | ||
| + | |||
| + | ===Cadillac radiator swap=== | ||
| + | Any of the Cadillac Fleetwood or Eldorado’s from '70 to '76 with a 472 or 500 cid engine will work. | ||
| + | |||
| + | ====Examples of donor vehicles==== | ||
| + | *1976 Cadillac Fleetwood or Eldorado. For example: [http://www.radiatorexpress.com/product.asp?part=1976+CADILLAC+FLEETWOOD++%2D+8%2E2+liter+V8+RADIATOR+Name+Brand+Replacement&part_id=1357&aaia_id=1026582 1976 Cadillac Fleetwood 8.2 liter V8 radiator]. | ||
| + | *Mid-70's Chevrolet truck with a 454. For example: [http://www.radiatorexpress.com/product.asp?part=1975+CHEVROLET+C20+PICKUP++%2D+7%2E4+liter+V8+RADIATOR+Name+Brand+4%2DRow+Capacity+Upgrade+%2828%22x19%22%29&part_id=39583&aaia_id=1031971 1975 Chevrolet C20 Pickup - 7.4 liter V8 radiator, 4-row capacity upgrade] (and, same radiator in aluminum: [http://www.radiatorexpress.com/product.asp?part=1975+CHEVROLET+C20+PICKUP++%2D+7%2E4+liter+V8+RADIATOR+All+Aluminum+4%2DRow+Capacity+%2828%22X19%22%29&part_id=218171&aaia_id=1031971 here]). | ||
| + | |||
| + | ===Swap procedure=== | ||
| + | Call around and find a boneyard that still has the fan, shroud and core support. You'll be using a new radiator and viscous drive fan clutch to bulletproof your installation. Make yourself a memo of the exact year and model the pieces came from so you can match up the parts. | ||
| + | |||
| + | You may or may not have to alter the fan clutch hub where it bolts to the water pump/pulley. Usually, the holes are slotted so you can make it work. If not, some minor surgery on the hub with a rat-tail file will do the trick. With the motor in the vehicle and finalized for position, bolt the fan clutch and fan to the water pump. Mount the Cadillac radiator and shroud to the Cadillac core support. | ||
| + | |||
| + | The Cadillac core support will probably be longer side to side than the stock one in the recipient vehicle. Retain the outer pieces of the recipient vehicle support where it bolts into the body and cut the middle part of the recipient vehicle support out with a reciprocating saw, leaving a few inches on each side. Then, measure the opening between the two stubs that are still bolted to the recipient vehicle and cut the Cadillac support to fit into this opening. It's better to leave a little more sheet metal on the Cadillac support until you determine the correct position of the fan where it engages the shroud opening. | ||
| + | |||
| + | Then, position the Cadillac support with radiator and shroud attached up to the fan, equalizing the distance between the fan blade tips and the inner circumference of the shroud all around. Move the shroud around the fan until you have the fan blades halfway in and halfway out of the shroud opening. You may need to tilt the top of the radiator/shroud back a little at the top to match the fan angle if the motor sits in the recipient vehicle with a rearward tilt. If you need a little more front to rear clearance for mounting the support, you can position the fan blades a little further inside the shroud, as long as the fan clutch is at least 1" from the radiator core. A little further out should be avoided if possible. | ||
| + | |||
| + | With that accomplished, simply attach the middle piece of the Cadillac support to the stubs of the recipient vehicle support. Use whatever pieces of sheet metal or whatever that you have to in order to make the connection. The Cadillac support may end up sitting forward of the stubs or a little behind them or it might fall exactly into place and you'll have very little welding to do to stitch the Cad support and the stubs together. Just use your head and figure out how to connect the sheet metal, then MIG it in place. | ||
| + | |||
| + | Now, you will have a radiator that will cool anything and you still have the stock attachment of the stubs to the recipient vehicle so you can use simple hand tools to disassemble it later if you have to; it'll all come out as one piece. | ||
| + | |||
| + | This swap may not be for everyone, you will have to judge that for yourself. Consideration should be given to the weight of the system when at full capacity, this could mean as much as 50 extra pounds on the front end. | ||
==Directing air flow== | ==Directing air flow== | ||
| Line 90: | Line 121: | ||
Most cars from 1960 and up used cross flow radiators. One of the reasons was a lower hoodline, and two, more cooling area was required to cool the larger engines. Cross flow radiators 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 radiator core, the 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. | Most cars from 1960 and up used cross flow radiators. One of the reasons was a lower hoodline, and two, more cooling area was required to cool the larger engines. Cross flow radiators 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 radiator core, the 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 found a way to keep cooling to a simple easy form. To do this, they pulled the tanks off the radiators that they were using and placed baffle plates in the tank covers. The baffles were placed so as to divide the radiator core section into three distinct areas. Water would enter the upper radiator inlet on the right side and would flow across the top section of the radiator to the left side, a baffle plate located 2/3 of the way down the tank caused the coolant to flow across the radiator to the right side to the right radiator tank. The coolant couldn't rise upwards because a baffle plate located 1/3 of the way down stopped it and forced it to head down lower in the right tank, where it again was drawn across the radiator 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? | + | Road course racers found a way to keep cooling to a simple easy form. To do this, they pulled the tanks off the radiators that they were using and placed baffle plates in the tank covers. The baffles were placed so as to divide the radiator core section into three distinct areas. Water would enter the upper radiator inlet on the right side and would flow across the top section of the radiator to the left side, a baffle plate located 2/3 of the way down the tank caused the coolant to flow across the radiator to the right side to the right radiator tank. The coolant couldn't rise upwards because a baffle plate located 1/3 of the way down stopped it and forced it to head down lower in the right tank, where it again was drawn across the radiator 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? Because if the water actually got to ambient, in this situation, then some part of this radiator would not be doing any cooling at all. So there is a trade off, as well as the slowing of coolant through the block in this set up. If it stays in the block too long, steam pockets, and bubbles will begin to overheat, so in theory, if double pass and triple pass worked in all situations, then factories would be making them in productions. |
| − | <br style="clear:both"/> | + | |
| + | <br style="clear:both"/> | ||
==Does radiator tube size matter?== | ==Does radiator tube size matter?== | ||
| + | |||
| + | <BR> | ||
| + | |||
The automotive radiator is essentially just another name for a heat exchanger, whereby combustion temperatures are transferred to the cooling system of the engine block and taken outside the block via flexible radiator hoses to be exposed to the cooling force of air through the radiator core, thus reducing the temperature of the coolant before returning it to the engine block. There are two restrictions in the system. One is the thermostat, which restricts flow and holds heat in the engine until warmed up, and the other is the radiator core tubes. The radiator tubes have to be of sufficient size so as to allow the coolant to flow through in an unrestricted manner, but also able to 'scrub off' BTU's or heat; which is based on the shape of the tube and the convection of heat away from the coolant to the outside air. A wide flat tube will expose more surface area to the outside flow of air than a narrow tube. The reason for this is more surface area is exposed to cooling. Look at the pictures located below and see why that is. | The automotive radiator is essentially just another name for a heat exchanger, whereby combustion temperatures are transferred to the cooling system of the engine block and taken outside the block via flexible radiator hoses to be exposed to the cooling force of air through the radiator core, thus reducing the temperature of the coolant before returning it to the engine block. There are two restrictions in the system. One is the thermostat, which restricts flow and holds heat in the engine until warmed up, and the other is the radiator core tubes. The radiator tubes have to be of sufficient size so as to allow the coolant to flow through in an unrestricted manner, but also able to 'scrub off' BTU's or heat; which is based on the shape of the tube and the convection of heat away from the coolant to the outside air. A wide flat tube will expose more surface area to the outside flow of air than a narrow tube. The reason for this is more surface area is exposed to cooling. Look at the pictures located below and see why that is. | ||
| − | |||
[[Image:Tube_sizes.gif|frame|Tube sizes.]] [[Image:Alum_vs_copper_brass.gif|frame. Aluminum vs. copper/brass]] | [[Image:Tube_sizes.gif|frame|Tube sizes.]] [[Image:Alum_vs_copper_brass.gif|frame. Aluminum vs. copper/brass]] | ||
| Line 104: | Line 138: | ||
===Sacrificial anode in aluminum radiators=== | ===Sacrificial anode in aluminum radiators=== | ||
| − | When running an aluminum radiator or any aluminum parts in contact with the water jacket, make sure to run a sacrificial anode | + | When running an aluminum radiator or any aluminum parts in contact with the water jacket, make sure to run a sacrificial anode. Aluminum is prone to electrolysis and corrosion and in many cases cannot be repaired. Usually zinc, magnesium or a combination of the two can be used as a consumable "edible" part to prevent the electro-displacement of the aluminum radiator. This may save the aluminum core, in the short run. |
==Coolant== | ==Coolant== | ||
| Line 124: | Line 158: | ||
== Radiator shroud== | == Radiator shroud== | ||
| − | Radiator shrouds are devices that control the exiting air from the radiator and direct it to a rearward sucking electric or mechanical fan. Shrouds can be made from plastic, fiberglass, | + | Radiator shrouds are devices that control the exiting air from the radiator and direct it to a rearward sucking electric or mechanical fan. Shrouds can be made from plastic, fiberglass, or metal. They cover the rear portion of the radiator. They allow air passing through the radiator to be ducted to the fan which directs air flow over the engine and out of the engine bay. In most cases, the mechanical fan will be inserted approximately 1/3 to 1/2 of the depth of the fan blades into the shroud, and no more than 3/4" from the tip of the blades to the edge of the shroud. |
== Radiator cap== | == Radiator cap== | ||
| Line 139: | Line 173: | ||
Note: This technique has been used on GM, VW and Porsche radiators to good effect. | Note: This technique has been used on GM, VW and Porsche radiators to good effect. | ||
| − | == Thermostat == | + | ==Thermostat== |
| + | {| | ||
| + | |[[File:Thermostats shaw vs regular 001.jpg|thumb|300px|Shaw (left) vs. economy type thermostat]] | ||
| + | |[[File:STATS 001.jpg|thumb|275px|A selection of thermostats]] | ||
| + | |} | ||
The thermostat has two important jobs to perform; to accelerate engine warm-up and to regulate the engine's operating temperature. A quality thermostat ensures excellent fuel economy, reduces engine wear, diminishes emissions and blow-by, improves cold weather drivability, provides adequate heater output, and deters overheating. This is accomplished by blocking the circulation of coolant between the engine and radiator until the engine has reached its predetermined temperature. The thermostat then opens as required in response to changes in coolant temperature to keep the engine's temperature within the desired operating range. | The thermostat has two important jobs to perform; to accelerate engine warm-up and to regulate the engine's operating temperature. A quality thermostat ensures excellent fuel economy, reduces engine wear, diminishes emissions and blow-by, improves cold weather drivability, provides adequate heater output, and deters overheating. This is accomplished by blocking the circulation of coolant between the engine and radiator until the engine has reached its predetermined temperature. The thermostat then opens as required in response to changes in coolant temperature to keep the engine's temperature within the desired operating range. | ||
| − | Thermostats have a “rated” temperature such as 180º | + | Thermostats have a “rated” temperature such as 180º or 195º. This is the temperature the thermostat will start to open, give or take a few degrees. |
Usually located within a metal or plastic housing where the upper radiator hose connects to the engine, most of today’s thermostats utilize the "reverse poppet" design, which opens against the flow of the coolant. Thermostats have a wax filled copper housing or cup called a "heat motor" that pushes the thermostat open against spring pressure. | Usually located within a metal or plastic housing where the upper radiator hose connects to the engine, most of today’s thermostats utilize the "reverse poppet" design, which opens against the flow of the coolant. Thermostats have a wax filled copper housing or cup called a "heat motor" that pushes the thermostat open against spring pressure. | ||
| − | As the engine's coolant warms up, the increase in heat causes the wax to melt and expand. The wax pushes against a piston inside a rubber boot. This forces the piston outward to open the thermostat. Within 3º or 4º | + | As the engine's coolant warms up, the increase in heat causes the wax to melt and expand. The wax pushes against a piston inside a rubber boot. This forces the piston outward to open the thermostat. Within 3º or 4º of the thermostat preset/rated temperature which is usually marked on the thermostat, the thermostat begins to unseat so coolant can start to circulate between the engine and radiator. It continues to open until engine cooling requirements are satisfied. It is fully open about 15º-20º above its rated temperature. If the temperature of the circulating coolant begins to drop, the wax element contracts, allowing spring tension to close the thermostat, thus decreasing coolant flow through the radiator. |
On some applications, the thermostat performs an additional function. It closes off a bypass circuit inside the engine when it opens the radiator circuit. The bypass circuit circulates coolant inside the engine so that hot spots can’t form when the radiator circuit is closed. | On some applications, the thermostat performs an additional function. It closes off a bypass circuit inside the engine when it opens the radiator circuit. The bypass circuit circulates coolant inside the engine so that hot spots can’t form when the radiator circuit is closed. | ||
| Line 155: | Line 193: | ||
There is no such thing as a thermostat that will fail in a “safe” position. All thermostats will fail in either a closed or open position. One brand claims it fails in a safe position, but it simply locks itself open when it is a full stroke open position. It will not spring open if it fails in a closed position. | There is no such thing as a thermostat that will fail in a “safe” position. All thermostats will fail in either a closed or open position. One brand claims it fails in a safe position, but it simply locks itself open when it is a full stroke open position. It will not spring open if it fails in a closed position. | ||
| − | A thermostat fails “open” if the return spring breaks or debris prevents the thermostat valve from fully seating or closing. In this instance the thermostat allows continuous coolant flow to the radiator; therefore, the engine will be | + | A thermostat fails “open” if the return spring breaks or debris prevents the thermostat valve from fully seating or closing. In this instance the thermostat allows continuous coolant flow to the radiator; therefore, the engine will be over cooled. The tangible effects are poor warm up and heater performance, increased engine emissions and reduced fuel economy. For these reasons, an engine should never be operated without a thermostat in place, even in extreme temperatures. |
A thermostat will fail “closed” if the wax element has been damaged by overheating (from loss of coolant, a defective electric cooling fan or fan clutch) or corrosion (from not changing the anti-freeze often enough). This failure prevents the flow of coolant to the radiator; therefore, the engine will be overheated. The tangible effects are a boil over, the inability to operate the vehicle, and the likelihood of severe engine damage. For these reasons alone, when an engine overheats, it’s a good idea to replace the thermostat whether it caused the problem or not. | A thermostat will fail “closed” if the wax element has been damaged by overheating (from loss of coolant, a defective electric cooling fan or fan clutch) or corrosion (from not changing the anti-freeze often enough). This failure prevents the flow of coolant to the radiator; therefore, the engine will be overheated. The tangible effects are a boil over, the inability to operate the vehicle, and the likelihood of severe engine damage. For these reasons alone, when an engine overheats, it’s a good idea to replace the thermostat whether it caused the problem or not. | ||
| Line 179: | Line 217: | ||
'''NOTE:''' The old type of thermostat used metal bellows filled with a liquid. The condensed liquid would "suck" the bellows closed. This type of thermostat always fails in the open position which is extremely convenient as one does not have to buy a new cylinder head or engine. Nowadays this type is very difficult to obtain. | '''NOTE:''' The old type of thermostat used metal bellows filled with a liquid. The condensed liquid would "suck" the bellows closed. This type of thermostat always fails in the open position which is extremely convenient as one does not have to buy a new cylinder head or engine. Nowadays this type is very difficult to obtain. | ||
| − | ==SBC 400 cooling== | + | ==GM== |
| − | From a [http://www.chevyhiperformance.com/techarticles/90678_small_block_400_cooling_tricks/ | + | ===SBC 400 cooling=== |
| + | From a [http://www.chevyhiperformance.com/techarticles/90678_small_block_400_cooling_tricks/ Chevy High Performance] article: | ||
This 1003 high- performance Fel-Pro head gasket (below) features larger 7/16-inch coolant passages (a) that will produce greater coolant flow to prevent excessive heat buildup between the center cylinders. The high-performance Fel-Pro gaskets also reduce coolant flow in the indicated areas (b) to help redirect the coolant between the center cylinders. If necessary, you may have to drill a 7/16-inch hole (c) in the block to increase coolant flow between the center cylinders. Only do this when the engine is completely disassembled to prevent iron drill chips from damaging the engine. | This 1003 high- performance Fel-Pro head gasket (below) features larger 7/16-inch coolant passages (a) that will produce greater coolant flow to prevent excessive heat buildup between the center cylinders. The high-performance Fel-Pro gaskets also reduce coolant flow in the indicated areas (b) to help redirect the coolant between the center cylinders. If necessary, you may have to drill a 7/16-inch hole (c) in the block to increase coolant flow between the center cylinders. Only do this when the engine is completely disassembled to prevent iron drill chips from damaging the engine. | ||
[[File:Felpro sbc 400.jpg]] | [[File:Felpro sbc 400.jpg]] | ||
| + | |||
| + | ==Ford Motor Company== | ||
| + | *[http://www.jalopyjournal.com/forum/showthread.php?t=303600&highlight=ford+short+water+pump Info on pulleys, etc.] | ||
==See also== | ==See also== | ||
Your Privacy Choices