The V8 Owners Forum -

hello all,

Back working on my 4.6 engine re-build again after a long break.

I'm thinking that the water pump from the rover v8 4.6 (gems type) spins in the opposite direction to the 3.5 & 3.9 type.

Does this mean I can still have the thermostat in the position where it is in the 3.5 & 3.9 engine, or would I be best keeping it where it is on the 4.6 engine.

IE on the bottom output of the rad?

I know the 4.6 thermostat is a different type too, and has a bypass water pipe.

But which is really the best system to use older 3.5 or newer 4.6 system.

I only ask I need as much cooling as possible in a westfield with somewhere close to 300bhp.

cheers

scott

scott

I think the two aspects are not really connected. The water pump is just that - the direction of it is just a matter for the belts and pulleys.

The configuration of thermostat / bypass etc is separate. My two pence worth is that the P38 Range Rover is the latest and therefore presumably best cooling system. It's a big heavy car, so it is working pretty hard.
I don't know what the difference is between a top stat and a bottom stat, so maybe you are best guided by the inlet manifold you have.

Chris.

How different is the Gems thremostat arrangement to the Thor arrangement? They certainly use the same cows udder thermostat thing. If so Megasquirts for V8s sell thermostat conversion kits that make it like the older 3.5.

https://www.megasquirt-v8.co.uk/ms_thor.php

Garry

i was just wondering if the direction of the water pump on the 4.6 setup would cause problems with the thermostat in the 3.5 manifold position?

Does anyone use the discovery 2 v8 cooling layout maybe?....is it any better than the range rover 2 layout?

Discovery 2 uses a bypass thermostat at 82degc, but with only 2 ports, as I have limited space to get all the pipe work in, this layout might be better for me.

So I might end up with a hybrid system somewhere between the two.

Just thinking ahead, before it need to plumb it.

regards

scott

anyone had the money to buy this....I know its for a tvr.

But could replace the 4.6 gems thermostat, with the bypass ports for heater etc....

not cheap though...

http://www.racetechdirect.co.uk/e2713-t ... engine.asp

but you can use a 74 or 82degc stat of your choosing.

regards

scott

While the pump turns the opposite direction on the serp engines the coolant flow is the same direction as the older engines.

I gave a serp 4.6 with 3.5 carbs and 3.5 cooling system and there are no issues.

The water pump's direction is not really important, they each pump the coolant in the same direction, so that would not effect using the 3.5 thermostat location.

I'm using a remote thermostat in my 4.6 V8 Rush (with intercooler blocking part of the rad) like used in the Gems but on with two ports, they have different temps depending on the colours, black, grey cream etc..

Mine seems to work fine. On of the benefits of the remote thermostat housing is that when open it actually closes off the bypass circuit so the rad gets full flow. This doesn't happen with the older setup. Also there used a remote setup on the newer k series to help reduce thermal shock in the engine which can only be a good thing?

Tom.

thanks, makes sense now that the water goes around the same way.....just the pump directions are different.

Yes i think to have a bypass will help, hard to work out actual plumbing routes when engine is still out of the car.

Was trying to think ahead, but i now know to think about a bypass and the pipe work when it comes to assembling the cooling system

cheers

scott