LT5 Thermostats. 1. LT5 Thermostat operation The LT5 thermostat sits in two cavities and is located on the outlet side of the radiator. On one end of the thermostat is the first valve pressure relief that expands and opens to excessive radiator pressure but only relative pressure over and above that normal thermal expansion radiator pressure. C4 ZR1 Discussion General ZR1 Corvette Discussion, LT5 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track. That valve is in the first cavity which is exposed to coolant outlet flow. In the second cavity is the second thermostat valve temperature relief which controls coolant inlet flow depending on engine temperature. You will notice there is BUILT IN BYPASS on the lower brass flange two slots to make sure the Coolant reaches constant and even temperatures as quickly as possible as this allows coolant to circulate in and out of the block Not Through The Radiator before it reaches a bit less than 1. F. It IS Important to have those two slots on the Recirculating Flow end of the Thermostat for the LT5. You want to INSTALL The Thermostat squarely in the Housing making sure the rubber gasket is not pinched or otherwise corrupted as the Slotted End of the Thermostat could end up bound from opening or closing if the Thermostat is not squarely seated. One event could blow your Stock Radiator at High RPMS and the other event could cause Over Heating as the flow through the radiator would not be maximized. GM found at high rpm and high coolant flow, excessive pressure in the radiator, due to its restriction, would blow the rubber seals between the side tanks and the core. C6 Corvette Lowering Bolt Installations' title='C6 Corvette Lowering Bolt Installations' />GM did not want to design a specific LT5 radiator, so the solution was the radiator bypass which opens when the pressure differential across the radiator reaches a certain level. This bypass valve is part of the thermostat and, when open, allows coolant to recirculate within the engine. LT5 Coolant System Discussion. ZR1 provided this photo in the LT5 Coolant System Discussion My thoughts here on the Bypass pressure of the thermostat which increases as the Bypass opening increases. The variable pressure from spring loaded Bypass the Radiator sees as it happens except for the head loss in the hose length differencesflow rate differences to the Thermostat Bypass as compared to the hose length differenceflow rate difference to the Radiator Inlet. That Thermostat Bypass Pressure depending on opening of the Bypass since it is sprung will be approximately equal to the total Head Loss of the flow through the Radiator. As the Bypass spring is compressed By increased Water Pump Flow so goes the increased head loss through the Radiator resulting in greater Radiator Coolant Flow to create that greater Head Loss. P. O. Box 16 13550 Three Oaks Rd. Sawyer, MI 49125. C1 to C7 x20ACx201C Only Corvette Central has it all mailcorvettecentral. Wheel Of Steel Haulin Crack Cocaine here. Kilauea Mount Etna Mount Yasur Mount Nyiragongo and Nyamuragira Piton de la Fournaise Erta Ale. Technical Help from the Solid Axle Corvette Club. To submit a technical question regarding a 1953 to 1962 Corvette, simply email sacctechsolidaxle. Issuu is a digital publishing platform that makes it simple to publish magazines, catalogs, newspapers, books, and more online. Easily share your publications and get. We then have Greater Coolant Flow Bypassed and Greater Coolant Flow through the Radiator. The Bypass spring does not keep the head loss through the radiator constant but does keep the head loss through the radiator within limits. LT5 Thermostats. To assure I have the correct thermostat, I use the 1. Thermostat sold by Marc Haibeck. I see no difference between a 1. F thermostat and a 1. Full Open Head Loss once the coolant temperature has reached 1. F I know the 1. 90 deg F will be reached slower with a 1. F Thermostat but that is the only difference in that you reach the same Coolant Temperature at different rates of temperature increase. Kind of like using light weight pulleys to save HP which HP is only realized on acceleration as the rotational velocity of the pulley changes. Nothing is gained in a constant velocity constant speed situation. See Defective Stant Thermostats by Marc Haibeck. Replacing Thermostat or Lower Radiator Hose A. You really have to separate the thermostat housing and unbolt the bracket from the half that is bolted to the frame with two bolts pointing up. Two bolts that go into the thermostat housing also go through that bracket one short bolt and one bolt that holds the thermostat halves together for which there are two of those longer bolts with one NOT going through the Thermostat Housing Bracket. Separate the thermostat housing half that bolts to the frame and remove it with bracket with the old short hose use razor blade on that hose lengthwise if you have to remove it from the radiator Connector. If you are using Silicon Hose it will be hard to slip on the Thermostat Housing and Radiator Connectors but with a little permatex it can be done fairly easily. Slip that hose onto the thermostat half first with the thermostat half in hand. Then with a bit more permatex on the radiator Connector, push the hose attached to the thermostat housing half you removed on that connector to a depth such that the thermostat housing half lines up perfectly with the mating surface of the other housing half that you stick the thermostat into the thermostat housing half you did not remove. Tighten hose clamps AFTER See B Below you get the two thermostat housing half bolts installed and tightened including the short bolt through the Bracket and including the Bracket bolts to the Frame. Make sure you put the short bolt that just goes through the bracket in the correct place in the threaded hole on the thermostat housing half you removed. B. Lastly. tighten the hose clamps such that the clamp is just inside the raised ring on the connectors to make sure the Silicon Hose does not slip off especially if you use Permatex before the Permatex cures. Notes A. Regarding the thermostat popping out it will not stay put unless you kind of glue it in with permatex it will pop out about 18 inch as it is preloaded a bit in the housing. B. I use a putty knife also just to keep the thermostat gasket from being pinched. If the two halves of the housing mate up tight with just finger torque on the bolts you know you have not pinched the gasket. C. Do NOT over tighten the thermostat housing bolts as it is not necessary for a complete coolant seal with the thermostat rubber gasket properly in place. D. Tighten the lower radiator hose clamps such that they are accessable if you have to repeat this process. Radiator Hose Clamps Orientation. E. Before you completely fill the radiator with antifreeze coolant, first put a gallon of distilled water in the drivers side coolant hose and check for any leaks in and around the thermostat housing. Just In Case F. If you do not remove the two 1. Getting the air out of the Coolant flow It is assumed that the air gets pushed out of the injector housing coolant manifolds on each side equally since they are higher than the radiator coolant line going back to the coolant expansion tank on passenger side the highest point in the coolant system. This is assumed for a system in which the TBPlenum coolant paths have been blocked off. It appears that the water pump pressure into each cylinder block right and left would be equal since the coolant flow is separated on the face of the front cover where the water pump is mounted. There are two holes of equal size that go into the front of each cylinder block right and left from the front cover. In other words, the coolant is not pushed from the water pump into a single flow after which the flow is divided but rather the coolant flow is divided at the impeller of the water pump. If the water pump can pump 1. GPM 3. 85 cubic inchessec through two ports lets assume 1 14 inch diameter or 1. That is intuitively enough flow to prevent a bubble of air going the other way in that flow assuring all air is pushed out of the system. It is assumed the water pump is NOT air locked which is the first thing to check for when refilling with coolant Filling With Coolant and the Air Locked Water Pump. Thermostat bypass The radiator Bypass Hose see above coolant flow diagram contains the hot coolant coming from the passenger side injector housing as stated below in red. The other companion hose Radiator Inlet Hose coming from the drivers side injector housings goes to the top return line of the radiator.