The V8 Owners Forum -

Good afternoon, i'm trying to simplify coolant system on my tomcat 100 powered by a front mounted 4.6 gems and cooled by 2 rear mounted radiators. I removed complex p38 coolant sistem and fitted an internal thermostat just before the elbow, like older land rovers. The idea is:
A) connect exit 1 to the pipe that feed rear radiators
B ) connect exit 2 to heater matrix inlet (my heater have not an internal bypass, so when heater is off the flow will be blocked)
C) blank off the exit 4: i don't need plenum heating and the bleeding of circuit (when thermostat closed) will be done by the 4 mm hole that i drilled in top of thermostat. Rear radiators have they own bleeding system with expansion tank that will work when thermostat is open
D) just before water pump inlet (5 on pic), fitting a four way connector with one exit (to water pump) and 3 inlet (one from cooled water coming from rear radiators, one from heater matrix outlet and one coming from bypass (nr. 3 on picture)

is this setup correct or i'll have problems like poor coolant circulation with cold engine, pump cavitation or other type of issues?

You have no coolant flow path if the heater is off and the thermostat is closed.

So you need a link directly from 2 to 5.

Otherwise it should be OK provided the expansion tank is at the highest point.

Chris.

C) blank off the exit 4: i don't need plenum heating and the bleeding of circuit (when thermostat closed) will be done by the 4 mm hole that i drilled in top of thermostat. Rear radiators have they own bleeding system with expansion tank that will work when thermostat is open
D) just before water pump inlet (5 on pic), fitting a four way connector with one exit (to water pump) and 3 inlet (one from cooled water coming from rear radiators, one from heater matrix outlet and one coming from bypass (nr. 3 on picture)

He mentions about joining bypass to pump inlet, so that's ok - The problem is you have no way of restricting this flow as the temperature rises. The coolant will flow through path of least resistance and I suspect the bypass circuit will offer less resistance than a very long circuit through two radiators?

With the remote thermostat - that I replied to your PM, it gradually blocks off the remote circuit when upto temp so all flow is through the radiators, and not arround the bypass circuit. It also avoids you having to make some sort on manifold to link the pump inlets together. It also reduces the thermal shock potential you may get with long radiator pipe runs.

Tom.