2.9 Cooling System

2.9 Cooling System

Author
Discussion

orange_dodo

Original Poster:

694 posts

188 months

Tuesday 7th August 2012
quotequote all
There seems to be this idea that blocking or restricting one of the pipes in the cooling system fixes a design flaw in the cooling system on the 2.9 S. The engineer in me didn't really want to go fiddling without understanding exactly what I was doing so I have mapped out the cooling system as accurately as i could but I still can't figure it out so I thought I'd post it up here for comments.

Sorry the drawing is a bit crude but it's only a free drawing app I found quickly.



The pipes are correct although the flow directions are a bit of a guess, especially pipe B. Pipe B is the convoluted one that goes over the fan belt by the alternator and is the pipe that it is suggested is blocked off I believe. Also pipe D is actually 2 pipes, I'm assuming the main outlet from the thermostat and a smaller bypass hose.

I don't understand pipe B as it seems to be a radiator bypass that isn't regulated at all. The flow direction on B is a guess from where it is positioned on the water pump but it makes no sense. Surely it should be temperature controlled so when the engine is cold pipe B is used and the radiator is bypassed, when the engine is warm pipes A and C are used and B is blocked so the water is cooled.

It would be nice to get this sorted so there is a reference for the cooling system should anyone want to fiddle with it.

sighck

50 posts

213 months

Wednesday 8th August 2012
quotequote all
I think that you have made some errors in your drawing, can you please pm me the drawing and I'll correct it.

phillpot

17,105 posts

182 months

Wednesday 8th August 2012
quotequote all
sighck said:
I think that you have made some errors in your drawing
Good effort Tom but at a quick glance F doesn't look right ?

orange_dodo

Original Poster:

694 posts

188 months

Wednesday 8th August 2012
quotequote all
phillpot said:
Good effort Tom but at a quick glance F doesn't look right ?
I think F is the pipe that turns into a steel pipe that runs along the underside of the engine then pops out at the front somewhere. It's a little difficult to trace with the engine in and it pops into the block at the end I think but that's where it seems to go. I always assumed the heater matrix would get water from the hot output from the engine. Saying that I could have just got it wrong!

Sighck: The file is from a Mac program called Drawberry. It's a simple vector graphics drawing program so another vector graphics package may be able to edit it. I'll PM it to you though so you can have a play.

Tom

Griffinr

1,017 posts

173 months

Wednesday 8th August 2012
quotequote all
Pipe B is the problem one as it is the pump bypass and also bypasses the thermostat. On the S it is piped to the top of the rad so the water gets cooled which slows warm up. On the Granada 2.9 it is piped to the bottom of the rad so just recirculates with minimal cooling.
Mine is now modified as in this post http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Warms up quick and behaves perfectly.

Rob.

Scoobimax

1,892 posts

200 months

Wednesday 8th August 2012
quotequote all
Watching this thread with interest due to my escapades last year in Europe but unfortunately nothing technical to add

jwoffshore

460 posts

253 months

Wednesday 8th August 2012
quotequote all
Based on looking at a V6 Sierra, the flow in B is actually the other way around. B is drawing water into the pump and that is why it messes up the S cooling, because it is effectively making a short circuit via the swirl pot and reducing the flow through the rad.

From memory, in the Sierra pipe B feeds from the header tank to the pump and provides the "fill" for the system. A very small bore bleed pipe feeds from the top of the engine to the header, so over time there is just a very slow circulation through the header. The Sierra pressure cap is on the header(!!!!) but there is of course no swirl pot. The TVR is plumbed all differently and the "header tank" on the TVR I think is intended only as a catch/overflow tank, hence the pressure cap on the TVR is (in my opinion!!!) intended to go on the swirl pot.

I think the TVR would work a whole lot better with a proper pressurised header as per the Sierra. Then you would need a larger capacity header tank and feed pipe B from the header to the pump to fill the system.

Edited by jwoffshore on Thursday 9th August 00:53

AutoAndy

2,265 posts

214 months

Wednesday 8th August 2012
quotequote all
...looking forward to seeing this resolved. Forget the search for Nessy, bigfoot, Higgs Boson, or the source of S indicators, this is the big one.

I have not got anything useful to add now, but will throw my threepenny's worth in if I can. Good luck with it Tom, I know you have the engineering dedication of a rottweiler hanging onto a postmans leg...I just hope you can sort it before it takes over your life, your living room wall, and your sanity.

orange_dodo

Original Poster:

694 posts

188 months

Wednesday 8th August 2012
quotequote all
Thanks for the comments, right version 2...



I've switched the direction of B and added H which is the thermostat bypass. I tried adding a swirly arrow in the swirl pot but my artistic skills aren't up to it!

Looking at that diagram assuming it is correct then the thermostat shouldn't be on the engine but should be on the swirl pot outlet and should either divert water to the radiator or back to the water pump. ie if the engine is cold the water should go down B to the water pump, and if the engine is warm it should go down C. Lots of ideas for rerouting the cooling system are popping into my head now!

If anyone has any other corrections I'll add them.


Sighck: I can't PM attachments so I have PM'ed you so you can reply and I can send the file.

Scoobimax

1,892 posts

200 months

Wednesday 8th August 2012
quotequote all
And once you've sussed out the flow, perhaps you can tackle where the pressure cap goes and the blanking cap?

I'll get me coat........ getmecoatbyebye

HvdWeerden

1,736 posts

199 months

Thursday 9th August 2012
quotequote all
And then explain why the heater matrix gets cold water ?

orange_dodo

Original Poster:

694 posts

188 months

Thursday 9th August 2012
quotequote all
Scoobimax said:
And once you've sussed out the flow, perhaps you can tackle where the pressure cap goes and the blanking cap?

I'll get me coat........ getmecoatbyebye
I don't think we should get into that again even if we get this cooling system sussed!!


HvdWeerden said:
And then explain why the heater matrix gets cold water ?
Well cold is a relative term but your right it would make morse sense to take the water that has just got heated up by the engine. The outlet from the engine could be anywhere in the cooling loop though as it comes out the block I think so it could be later in the loop.

phillpot

17,105 posts

182 months

Thursday 9th August 2012
quotequote all
HvdWeerden said:
And then explain why the heater matrix gets cold water ?
F is still not right (imo), goes to a connection on inlet manifold near thermostat not the swirl pot?

glenrobbo

35,083 posts

149 months

Thursday 9th August 2012
quotequote all
Correct me if I'm wrong ( I often am! ), not really shown in Tom's diagrams, but is it best to have hot inlet at the bottom of the rad & cooled outlet at the top? This takes advantage of the thermo-syphon effect with the water pump having to do less work.

Or would this mean that coolant passes too quickly through the rad & isn't cooled sufficiently?

Or have I managed to open up a new can of worms?yikeswhistle

Edited by glenrobbo on Thursday 9th August 10:05

phillpot

17,105 posts

182 months

Thursday 9th August 2012
quotequote all
glenrobbo said:
Correct me if I'm wrong
Yes you are wink

as water cools it drops



orange_dodo

Original Poster:

694 posts

188 months

Thursday 9th August 2012
quotequote all
AutoAndy said:
...looking forward to seeing this resolved. Forget the search for Nessy, bigfoot, Higgs Boson, or the source of S indicators, this is the big one.

I have not got anything useful to add now, but will throw my threepenny's worth in if I can. Good luck with it Tom, I know you have the engineering dedication of a rottweiler hanging onto a postmans leg...I just hope you can sort it before it takes over your life, your living room wall, and your sanity.
So does my wife!

I've had a break from fiddling with the TVR for a while but now I am planning cold air intakes, pedal improvements and cooling system modifications! The worrying thing is this is what keeps me sane silly

glenrobbo

35,083 posts

149 months

Thursday 9th August 2012
quotequote all
phillpot said:
glenrobbo said:
Correct me if I'm wrong
Yes you are wink

as water cools it drops


Oh well, no worms for me thensmile
At least I had a nice little run out in this glorious sunshine.
(Had to test my cooling system is still working.)

orange_dodo

Original Poster:

694 posts

188 months

Thursday 9th August 2012
quotequote all
Mike your right, had a closer look at the heater circuit and I think it is a little closer to the truth now although I don't think it is completely right. I have no idea what the flow direction is but E seems to be close to the water pump I think, its a little difficult to see. The colours for E and F are probably wrong but I'll fix them when I figure out the routing for certain.

Take 3...


phillpot

17,105 posts

182 months

Thursday 9th August 2012
quotequote all
Bu**er, spent hours doing this then found you've already done it ( slightly neater too) wink

Reckon hot water from inlet manifold, near stat, goes to heater matrix then cooler water returns to pump?
(can take some temperature readings over the weekend to confirm)


techbotics

1,803 posts

181 months

Thursday 9th August 2012
quotequote all
where does the hot water from the bloc go with the stat closed?

Damian