Vortec L31 cylinder head
(→Recommended spark plugs) |
(→Vortec water bypass) |
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==Vortec water bypass== | ==Vortec water bypass== | ||
8[http://www.hotrodders.com/forum/thermostat-bypass-vortec-conversion-161468.html#post1581704 Thermostat bypass] Hotrodders forum thread | 8[http://www.hotrodders.com/forum/thermostat-bypass-vortec-conversion-161468.html#post1581704 Thermostat bypass] Hotrodders forum thread | ||
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| + | The L31 (and L30) small block, along with the 4.3L (L35, LU3) came with a redesigned water pump with a threaded boss on the impeller which accepts a fan clutch held with a nut instead of the 4 bolt setup common with 1995 and earlier SBCs. A water pump bypass port was added to the intake manifold where the cylinder block for 1996+ will have the water pump bypass hole eliminated - some 1996-2003 production cylinder blocks will have the bypass hole eliminated and undrilled (visual cue is the RH water pump port where the bypass hole is absent and undrilled - this also includes cylinder blocks with 2 holes undrilled for the timing cover (much like engine blocks casted after 1992 the fuel pump hole is undrilled and unmachined - aftermarket 5.7L crate motor assemblies including the L31 used by Mercury Marine/MerCruiser will have the water pump bypass hole and fuel pump hole drilled out and machined. One solution is the following - use a high flow thermostat or run a water bypass from the heater hose port to the radiator and/or heater core. | ||
==Optional GMPP Vortec parts== | ==Optional GMPP Vortec parts== | ||
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