Don Terrill’s Speed-Talk

Trying to design an open cooling system for a marine race application for an LS3 and need to know what the coolant flow pattern is, can anyone help me? Flow schematics would be ideal. Thanks in advance.

Well how about.........is the cooling system conventional or reverse? I've been told it's a hybrid of each..... whatever that means??

I have searched the internet to no avail, called GM parts and service departments only to be told that their shop manuals don't have any cooling system schematics any more.

There has to be someone on here that knows something about this subject.....please help. Or is this such a stupid question, no one wants to waste their time to answer, in which case I appologize. But, please say something!

Here is the coolant flow cycle as described in the service manual for the LS2. The LS3 should be the same.

Cooling Cycle
Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. Some coolant will then be pumped from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost.

Coolant is also pumped through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.

The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.

Coolant is also directed to the throttle body. There it circulates through passages in the casting. During initial start up, the coolant assists in warming the throttle body. During normal operating temperatures, the coolant assists in keeping the throttle body cool.

From the cylinder heads, the coolant is then forced to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine is warmed, or it will flow through the thermostat and into the radiator where it is cooled and the coolant cycle is completed.

DrkPhx wrote:Here is the coolant flow cycle as described in the service manual for the LS2. The LS3 should be the same.

Cooling Cycle
Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. Some coolant will then be pumped from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost.

Coolant is also pumped through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.

The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.

Coolant is also directed to the throttle body. There it circulates through passages in the casting. During initial start up, the coolant assists in warming the throttle body. During normal operating temperatures, the coolant assists in keeping the throttle body cool.

From the cylinder heads, the coolant is then forced to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine is warmed, or it will flow through the thermostat and into the radiator where it is cooled and the coolant cycle is completed.

Thank you for your response. So the cooling system is basically the same as in the origional sbc?

i looked up the coolant flow path for a 2010 ls3 and its the same as the ls2

sanfordandson wrote:i looked up the coolant flow path for a 2010 ls3 and its the same as the ls2

Was it a diagram or just vaguely described? Any way you can send or post a copy of this?