Rover V8 Coolant Circulation Direction

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garrycol
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Rover V8 Coolant Circulation Direction

Post by garrycol » Sat Sep 14, 2019 4:48 am

With a Rover V8 3.5 with carbs which direction does the coolant flow? Out the inlet manifold through the thermostat into the top radiator hose, into the top of the radiator through the radiator, out the bottom hose and back to the water pump or is it vice versa?

I have a Rover v8 with the 4.0 serpentine timing cover where the water pump turns the opposite way to the V belt 3.5. In the system I have the water pump takes the coolant from the engine block, into the bottom of the radiator up through the radiator and out the top of the radiator, back to the thermostat and into the inlet manifold etc.

The problem I have is that because the thermostat is closed no hot water gets to it to open it - yes the thermostat is all OK - you can touch the thermostat housing and it is still cold when the radiator is boiling. If you touch the radiator end of the top radiator hose it is very hot as it should be but the thermostat end is cold because the thermostat is closed (because everything is cold) an not allowing hot coolant back to to the engine.

It is almost as if I need the thermostat in the bottom radiator hose.

Open to ideas.

Thanks

Garry



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Ian Anderson
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Re: Rover V8 Coolant Circulation Direction

Post by Ian Anderson » Sat Sep 14, 2019 7:40 am

Simplest is to drill a 1/4 inch hole in the outside of the thermostat and position this at top to help air bleeding.

It will allow some coolant flow and allow the hot stiff to get to the thermostat and allow it to open

Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.

garrycol
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Re: Rover V8 Coolant Circulation Direction

Post by garrycol » Sat Sep 14, 2019 8:52 am

Ian Anderson wrote:
Sat Sep 14, 2019 7:40 am
Simplest is to drill a 1/4 inch hole in the outside of the thermostat and position this at top to help air bleeding.
Hi Ian - thanks for that but I am not sure I follow - can you explain a bit further? For a dummy :lol:

Thanks

Garry

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Re: Rover V8 Coolant Circulation Direction

Post by Ian Anderson » Sat Sep 14, 2019 8:41 pm

Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.

garrycol
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Re: Rover V8 Coolant Circulation Direction

Post by garrycol » Sun Sep 15, 2019 2:14 am

Ok got it now :idea: - thanks - my initial thought was you were referring to drilling a hole in the thermostat housing :? .

Cheers and thanks

Garry

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Re: Rover V8 Coolant Circulation Direction

Post by unstable load » Thu Oct 17, 2019 11:59 pm

garrycol wrote:
Sat Sep 14, 2019 4:48 am
the water pump takes the coolant from the engine block, into the bottom of the radiator up through the radiator and out the top of the radiator, back to the thermostat and into the inlet manifold etc.
That doesn't sound right to me.
I understand it that hot water comes in the top and cools and then out the bottom, so the water outlet in the inlet manifold goes to the top of the rad and the rad outlet at the bottom goes to the pump inlet.

Are you running the thermostat in the inlet manifold or the separate P38/Disco one?
Cheers,
John

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Re: Rover V8 Coolant Circulation Direction

Post by Seight-V8 » Fri Oct 18, 2019 11:29 am

Maybe this might help.

https://www.landyzone.co.uk/attachments ... jpg.65691/

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scott

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Re: Rover V8 Coolant Circulation Direction

Post by SuperV8 » Fri Oct 18, 2019 12:38 pm

unstable load wrote:
Thu Oct 17, 2019 11:59 pm
garrycol wrote:
Sat Sep 14, 2019 4:48 am
the water pump takes the coolant from the engine block, into the bottom of the radiator up through the radiator and out the top of the radiator, back to the thermostat and into the inlet manifold etc.
That doesn't sound right to me.
I understand it that hot water comes in the top and cools and then out the bottom, so the water outlet in the inlet manifold goes to the top of the rad and the rad outlet at the bottom goes to the pump inlet.

Are you running the thermostat in the inlet manifold or the separate P38/Disco one?
Yes, I agree doesn't sound right - it doesn't matter which direction the pump turns - in both versions (V-belt and serp) the coolant flows in to the pump from the bottom radiator hose (where it's coldest) - through the engine - and out the top hose into the top of the rad (where its hottest).

I presume you must have a remote thermostat housing in the bottom hose? as I find it difficult to understand how if you had a thermostat in the inlet manifold (top hose) that it could be cold when the engine is hot!
So presuming you do have a remote thermostat in the bottom hose? then there should also be a bypass hose from the inlet manifold outlet (hot) into the thermostat housing so the housing can 'sense' engine temperature and bleed the cooler rad coolant into the engine and so coolant still flows when the thermostat is closed.

Tom.
Dax Rush 4.6 supercharged V8 MSII

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