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What do you know about revers flow cooling?

Discussion in 'The Garage' started by great scott, Feb 8, 2003.

  1. great scott

    great scott 1/2 ton status

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    When was it used(just TBI)? How can you tell them apart(smoth or groved whater pump pulleys)? Did they ever come with V-belts? Good or bad?
     
  2. HarryH3

    HarryH3 1 ton status Author

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    I think you're confusing reverse flow cooling with reverse rotation water pumps. Most of the TBI trucks have a serpentine belt that wraps around the water pump pulley such that it rotates the pump in the opposite direction of a V-belt driven pump. This requires a water pump that has the impeller blades curved the oppsite direction from standard. However, the coolant still flows into the block, then into the heads, then back to the radiator (once the thermostat opens).

    Reverse flow cooling showed up with the advent of the LT1 engines in the Corvette, around 1992. On those engines, the coolant goes into the heads first, then into the block, then back to the radiator. This keeps the heads cooler so the engine can run a higher compression ratio without detonation problems. And just in case you were wondering, you can't convert a standard flow cooling system into a reverse flow cooling system. The LT1 is a completely redesigned engine that shares nearly no parts with earlier small blocks, and was designed from the beginning for reverse flow cooling. /forums/images/graemlins/cool.gif
     
  3. ZonkRat

    ZonkRat 1/2 ton status

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    My 88 SWB has the reverse rotation pump,think all with serpentine belt have it.They pump in the same direction,just rotate opposite dir because of the way belt is routed /forums/images/graemlins/thumb.gif
     
  4. 70~K5

    70~K5 1/2 ton status

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    HarryH3 said quote"And just in case you were wondering, you can't convert a standard flow cooling system into a reverse flow cooling system. The LT1 is a completely redesigned engine that shares nearly no parts with earlier small blocks, and was designed from the beginning for reverse flow cooling."

    Tell that to Smokey Yunik he used to convert standard motors to reverse cooling. /forums/images/graemlins/thumb.gif
     
  5. milspecjimmy

    milspecjimmy 1/2 ton status

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    only thing that is different on the LT-1 is the size of the water jackets, the heads, the timing components (opti spark only) and the intake. the rest of it, crank, rods, push rods, pistons, rings, cam, lifters are all interchangable
     
  6. HarryH3

    HarryH3 1 ton status Author

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    Leave it to Smokey to figure out a way to do it. But he had access to a lot of shops and tools that mere mortals find insanely expensive. /forums/images/graemlins/shocked.gif
     
  7. HarryH3

    HarryH3 1 ton status Author

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    Hmm, I've never had an LT1 apart, but I've got a Sept. 1991 copy of Car Craft that I kept because it has some great cutaway views of the LT1. Part of the story reads "The engine they created is certianly not a chip off the old small-block. Only a few parts--principally valvetrain and lubrication system components-- are interchangeable between the first and second-generation engines."

    But the bore and stroke remained the same, so it would make sense that more parts interchange than the story let on... /forums/images/graemlins/shocked.gif
     
  8. 70~K5

    70~K5 1/2 ton status

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    Hey I'm with you Harry, but never say never........ /forums/images/graemlins/thumb.gif
     
  9. Lonnie

    Lonnie 1/2 ton status

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    Here is some info on the LT1.

    It has an interchangable rotating assembly with the standard 1pc. seal small block. Block bolt pattern is the same but the Dr. side motor mount has 1 bolt hole moved.

    The reverse cooling, mechanical drive water pump & front mounted distributor are all specific to the LT1. Head bolt pattern is identical, but heads or gaskets do not interchange. Intake, pulleys etc are also non interchangable... but they make a carb intake/distributor setup to retrofit this engine to earlier chassis.

    Car Craft did not have much detail in '91 before this engine was released in the vette in '92.
    I build a lot of this type of engine for the Z28 & T/A guys. The reverse cooling does allow more compression to be run than normal (by keeping cylinder head / intake air temp lower) on pump fuel. 11:1 on pump premium is possible. Click on engine buildup details on the link below to show some engine details.

    Lonnies '95Z28
     

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