Originally Posted by Birdog 101
I have a 93 tbi 350 that is completely rebuilt with a air gap intake manifold by procomp it's a carb intake ..40 over flat top pistons moly rings stock crank stock rods hei dist 65,000 volt coil 750 carter carb stock fuel pump with holley fuel psi regulator with bypass ..vortec 906 heads and rv flat tappet cam hyd lifters ...serpintine set up off 93 tbi setup 93 tbi water pump with that being said i can't keep my motor cool i ran a bypass hose from top of water pump to top of intake and from water port under thermostat port back to radiator and about 6 or 7 holes drilled in thermostat about 1/8 inch any suggestions or something i'm doing wrong or may need to add i am at a stop please help!!!!!!
New engine against an old radiator?
So this really is no longer a computer controlled engine, right?
Let me get to two things that is the water pump and the fan if that is driven off the pump. If either of these were replaced it is not common but it does happen that the pump or fan or both are not for the GM serpentine system which turns them counter clockwise, that is reverse of the Vbelt engines. The only difference between these pumps is the impeller; the housing for both uses the same casting number, over the years I've hit pumps that were incorrectly boxed. The part number on the box is the only external identifier. This usually shows as marginal idle and low speed cooling that just comes off the tracks as speed and power needs grow. Similar things with fans having had a couple instances where the fan in the box was not the fan that should have been in the box. This is easier to check because you can see the blade pitch against the direction it turns to quickly determine if its sucking air through the core of blowing into the core. This typically cools rather OK at idle, but the engine just keeps getting hotter as speeds increase.
Radiator, just how old is this thing? Their performance doesn't improve with age mixing an old radiator with the cooling requirements of a new and powerful engine just doesn't work well. In this case the engine may cool fine at idle and low speed but as the speed comes up so does the temperature.