|08-24-2012 09:44 PM|
On this forum, you are like "Doc Vette" for engines. Your explanations are comprehensive, and right on point. I can't think of a more appropriate compliment, nor one more deserved. Thanks for sharing you wisdom, and your knowledge.
|08-24-2012 06:57 PM|
|Caprice Sleeper||Thanks for the help guys|
|08-24-2012 12:48 PM|
Gen I blocks all cool in the "normal" way of the pump introducing coolant into the front of the casting where it floods around the cylinder walls, then flows through passages into the heads. From the front of the heads it is gathered into a passage on the front of the intake manifold and returned to the radiator from the thermostat housing via a hose. This covers SBCs from 1955 to 1995 and G30 vans to 96. For the years 1955 through 1986 the SBC drove accessories including the water pump with V-belts, these rotate the water pump in the same clockwise direction as the crankshaft turns when viewed from the engine front. This is considered conventional pump rotation. In 1987 the SBC went to supporting the accessories on castings that bolt to the front of the engine in place of the sheet metal brackets previously used and with this change the multiple V-belt drive system was replaced with a single serpentine belt. The serpentine belt runs under the water pump pulley instead of over it as with the V-belt, this rotates the water pump in the opposite counter-clockwise direction to the V-belted engines. This also effects the fan blade pitch direction where the pump driven fan is used. These are considered to be reverse direction pumps not to be confused with the LT1, 4, and L99 reversed coolant flow.
One has to step around the pump rotation direction carefully when it comes to aftermarket serpentine belt systems some designs drive the pump with the belt passing over instead of under the pump pulley. These over the pulley type serpentine set-ups need to use the conventional drive direction (clockwise) pump.
|08-24-2012 12:33 PM|
|matt167||TBI was still standard flow, but because of the serpentine system, the pump pulley rides on the back side of the pulley, and that's why they need to be reverse rotation. If your doing a Vortec head swap, then your all good. Pulley system and everything is fine|
|08-24-2012 09:14 AM|
I have not been able to find any solid info on this subject. Is a 1990 305 TBI car engine with a factory roller cam a reverse coolant flow engine? The water pump is a reverse rotation design but does that mean the heads get coolant flow first? I want to make sure if I bolt on my 906 vortecs it won't overheat. I would think if my serpentine belt water pump is not compatible with the vortecs then I can just install the correct water pump and belt setup. Any clarity on the subject would be a great help. I will be running an edelbrock 2116 intake and a carb.