thermostat

[allanw]

G'day
I am about to take a leap in the dark and replace my 88c thermostat with a 82c one.Any comments re this procedure???????
AllanW.

[Jaffacakekilla]

http://www.mgf.ultimatemg.com/group2/co ... ostats.htm

http://web.tiscali.it/elise_s1/

http://www.mgfmavhh.ukf.net/

bypass mod

[plrobbo]

Hi Allan - a very good mod is to remove the thermo completely and insert a ring in it's place. Go to a Landrover spares place and buy a thermostat for the K serries engined Freelander. The thermo is the same as fitted to the 2003 cars onwards. Plumb it in aft of the two steel pipes that go under the car AND now you will have a 'remote PST' that gives a much better configuration to the cooling system. Just make msure that before you start - start the engine and as soon as the car is warming up determine which pipe carries the heat to the radiator - you then can't go wrong. The Thermo for the Freelander comes with an T fitting and 4 or 5 pipes that you can cut up to fit your system. Cheers Robbo.

[jonaf]

Hi Allan - a very good mod is to remove the thermo completely and insert a ring in it's place. Go to a Landrover spares place and buy a thermostat for the K serries engined Freelander. The thermo is the same as fitted to the 2003 cars onwards. Plumb it in aft of the two steel pipes that go under the car AND now you will have a 'remote PST' that gives a much better configuration to the cooling system. Just make msure that before you start - start the engine and as soon as the car is warming up determine which pipe carries the heat to the radiator - you then can't go wrong. The Thermo for the Freelander comes with an T fitting and 4 or 5 pipes that you can cut up to fit your system. Cheers Robbo.

When you're finished it may look like this:

[Debs]

Be careful which Thermostat you source since there are 3 types available:

Cream is 87°C With Medium Spring: It was first used on the Land Rover FreeLander as well as MGTF's from mid/late 2003 onwards.

Black is 82°C With Hard Spring: This is not suitable for K-Series motors.

Grey is 82°C With Light Spring: This is the latest being used on the Land Rover Freelander - Land Rover replace the old 87°C thermostat with this one if they have to open the coolant circuit. This is the one we use when retro fitting to Elises, MGFs and early TFs. THIS IS THE ONE YOU WANT!

[martyn0212]

hi where is the best place to get one of these from?

[Debs]

Any of the usual suspects:

PTP: http://www.ptp-ltd.co.uk/index.htm?

QED: http://qedmotorsport.co.uk/

Elise Parts : http://www.eliseparts.com/

[plrobbo]

Just to inform you all - I've now purchased an 82 DegC PRT from Brown & Gammons for GBP20.56 Pt No PEL 500. It looks (by thier web site) a dark grey colour/almost black. So, thanks to members for the info. One thing I did find out though, is that the Elise crowd go for the metal PRT. It would've been my choice but for the cost. My choice because it is inserted direct into the hot water pipe to the radiator with a bypass. This PRT more directly controls the flow rather than the original type of PRT. The original PRT controls the water FROM the radiator!!! Oh well, I'm a 'cheap scate'!

[Titanium]

I've just bought from a Land Rover dealer the soft spring LIGHT GREY thermostat part N. PEL500110

The dark grey is the 82°C hard spring, while the creamy one is the 87°C

[plrobbo]

Just to continue this thread a little further. I see by jonaf's diagram of the positioning of the remote PRT is for an MGF. Please corret me if I'm wrong - On the MGF the 'HOT' water to the radiator travels along the LH underfloor metal tube to the BOTTOM of the radiator & the 'COLD' water (as in his diagram) travels back to the engine along the RH underfloor metal tube, through the PRT (when it's open) to the engine.
NOW, on an MGTF (when fitted with the PRT as standard) the water flow to the radiator is reversed. I.e. the HOT water from the engine travels along the RH underfloor metal tube to the TOP of the radiator & the COLD water out of the BOTTOM of the radiator travels along the LH metal tube to the PRT to the engine (When the PRT is opened).
The big question is:
1. Am I correct in saying this?
2. If I am correct, from what year did the flow change?
According to all good engineering practice, (and on most cars) the flow of HOT water always travels to the TOP of the radiator.
I would appreciate it if some one can answer this question. The main reason too, is to point out to all members that to go by jonaf's diagram, IS INCORRECT FOR THE LATER MGTF cars.
Many thanks - Peter.

[mgtfnut]

Just a thought: the thermostat does not fully control the coolant operating temperature, merely the temperature it starts to open. The thermal efficiency of the radiator and pipework will determine the coolant operating temperature.

Also the F/TF have crossflow radiators, not the traditional north/south arrangement which probably originated in very early thermal flow designs.
Looking at my radiator, the manifold part at both ends are symmetrical and so I guess it doesn't really matter which way, or how the coolant crosses the heat exchanger matrix?

Just MHO.

[plrobbo]

To my understanding - The 'crossflow' radiator bit really does not have any bearing on the 'flow' really, to compared with a 'normal' radiator. The important thing is that the HOT (into the radiator) pipe is connected to the TOP of the plenim chamber and the COLD water back to the engine is connected to the BOTTOM of the opposite plenim chamber.
My question is this - why does the flow through the radiator in a MGF go the opposite way to the MGTF with a remote PRT?????? On my MGTF (with remote PRT) the HOT water travels along the RHS underfloor pipe to the TOP of the RHS of radiator & the COLD back to the engine comes out of the BOTTOM of the LHS of radiator then along the LHS underfloor pipe.

[Chris Tideswell]

My question is this - why does the flow through the radiator in a MGF go the opposite way to the MGTF with a remote PRT?????? On my MGTF (with remote PRT) the HOT water travels along the RHS underfloor pipe to the TOP of the RHS of radiator & the COLD back to the engine comes out of the BOTTOM of the LHS of radiator then along the LHS underfloor pipe.

This is thought to be some of the problem with original design of the F/02 TF's coolant system. The K-series engine was designed to have the thermostat on the incoming side of the engine, bearing in mind the engine was originally intended to be a low capacity lean-burn engine mounted in the fount of the car meaning that getting the engine to run at full operating temperature was paramount. The problem was/is that the engine was that when installed in the rear of the F/TF with the thermostat in the original configuration what tends to happen is that the coolant sitting in the radiator and pipes being cooled down sometimes to very low temperatures is suddenly released by the thermostat into the very hot engine head. This maybe the answer to why a HGF is more likely to happen in the European Autumn and winter then spring and summer.

To get around the problem for the 03MY TF MGR fitted PRT that not only works on the output side of the engine (to the radiator) but also opens under pressure. Not a total cure to the HGF but it does seem to have improved things.

[plrobbo]

Point taken - good one.
What I was mainly getting at here was that owners of MGF's (in particular) must (if they are fitting the PRT to their car) is to get the connection the right way. I.e. As in Jonaf's picture of the fittment of the PRT - this is for the MGF. If you are fitting one to the later cars it has to be to the LHS pipe. Am I correct in saying this?

[Titanium]

I'll install PRT this WE in my 02MY TF135.
I don't see any reason to modify the water circulation, PRT has to be installed on the return "cold" from the radiator pack, this is sure.
I've spent a lot of time reading as much as possible on this subject, I've also bougth either 82 grey and light grey. This is the first time a read this.
Are really different the F and TF radiator pack ? I'don't know.
It's common to move cross/down through because cold water is "heavier" than hot, so this will facilitate the flow.

[mgtfnut]

Haha, I've been thinking about this for a bit now as it's too cold to go crawling about under the car.
But - Plrobbo is right
My MY02 sends hot coolant down the LHS (sitting in the car)metal under floor pipe to the lower radiator connection, and exits through the top and comes back down the RHS metal coolant pipe.
It's only just dawned on me, although as it's a crossflow radiator it doesn't seem to have made any difference in the four years since fitting a PRT under the washer bottle

Come warmer weather, I'm going to shuffle things around to feed hot feed coolant to the top radiator connection when the stat opens. I've already re-routed the heater connections into both large bore coolant pipes using the nice OEM "Y" pieces, and fitted a 160 oil water/oil intercooler via the small 90* outlet from the cylinder head in basically a second, separate circuit that looks after itself and the cooler, together with the original jiggle valve.

I can't think why it takes so long to work out these things, it must be age related

[plrobbo]

Hi there mgtfnut - Happy New Year to all.
I think you have it all correct. When fitting the PRT to earlier than my03 cars - it's very important to remove the thermo (that's the thermo near the head) and insert a ring in the housing. The connection of the HOT water FROM the engine should go to the TOP radiator inlet connector (RHS) & cold from the radiator to engine out of radiator from the LHS bottom outlet. As I've said before - the early cars had the reverse of this BUT to normal engineering practices and thermal flow of water is alway HOT into the TOP of radiator and COLD out at the bottom outlet - doesn't matter if the radiator is a standard one or crossflow.
Cheers Robbo.

[mgtfnut]

Happy New Year down there

It's obvious when I think about it, but the two big-bore pipes cross over when they pass down by the exhaust manifold
As soon as the weather warms up, I'm going to sort that out, as the hot coolant exit from the head is on the RHS, and the return coolant rail is on the LHS.
So a bit of surgery on the existing rubber OEM hoses, or replacement with silicon to make the hose run more efficient. Also, I'll try to shorten the heater flow and return even more using the OEM "Y" pieces directly off the large bore pipes as I have now, except it will look and work that bit more effectively and give a bit more room for checking hose clips.
Yes, I know the argument about silicon hoses and the weakest link, but the environment in the engine compartment is fairly hostile to rubber, so I think it worthwhile to do in this area only.
I've spliced in a water temperature gauge probe into the return coolant rail, so using my Scangauge and the second temperature gauge on the dash, I can see the differential in coolant temperature through the PRT/radiator.

It takes another XPG with Gunmetal wheels TF owner to appreciate what you were on about earlier

[willyphixitt]

Hi Guys,

I've been following this thread with interest but have not made any comment up until now.

As the whole idea of modifying the cooling system of the F/TF is to maintain an even as possible and steady as possible working temperature of the engine, I would not want to change coolant flow direction before ascertaining temperatures at the inlets and outlets at both the radiator and engine - as a start. Here we have hotter coolant at the top of the engine (because of the combustion process) but as it is pumped round there may be no difference in achieving as constant an overall engine temperature as possible under all operating conditions by changing flow direction within the radiator. Bearing in mind that the oil is keeping the lower half of the engine in a steadier temperature environment, all aspects of the engine's working environment has to be carefully considered so that everything is working in harmony.

BTW, have any of you done any in depth testing on coolant flow direction?

More food for thought?

Happy New Year to you all.

willyphixitt

[mgtfnut]

Hi Bill, HNY.

I'm just getting round to sorting out the 1st speed fan setting, but first I want to get the fan motor out to see if I can lubricate the bearings. Looks like the clutch pedal needs removing

I've been using my crossflow radiator the "wrong" way round for 4 years now with no noticeable ill effects, even in mad hot air temperatures. Yes, I can see a temperature differential in winter months of about 10*C from leaving the head to going back into the pump suction rail to 5*C in the summer. I'm pretty certain the flow is good on my by-pass circuit 'cos it's all 32mm tubing from the cylinder head outlet back to the water pump. Although not clever enough to have data logging, I can see the cylinder head exit temperature rise when I climb a hill, and fall off again on the downhill side! The return leg temperatures lag behind and sort of average out, which is good. I can't spot the opening of the thermostat - nor would I want to as the stat is under the washer bottle and the stagnant radiator coolant slowly heat soaks up from the "open" leg, so when the stat opens and exposes full flow through the radiator, all the coolant is the same temperature. Most of the time the coolant is around 88*C.
Certainly watching the 2 gauges is interesting - must spend more time watching the road