Cooling system diagram

[miker]

Excellent post dandy!

And of course if you are right that the thermostat is the vital piece of kit that the cooling system revolves around on the bongo, then whilst it's vital to have the coolant loss alarm and the temp gauge mod to get an accurate temp reading, it follows that we are missing a final part to defend the cooling system ie a stat failure warning to complete the setup. Perhaps a combo of temp and fluid flow in a particular part of the system (or lack of flow) plus cooling fan running equals stat failure? Just thinking out loud so happy to be shot down!
So it follows that if Dandy is right and my thought is correct, then ALL we need is the right location and the right bit of kit to do the job!
Ps might just be simpler to replace the thermostat every year or two

[dandywarhol]

Thanks for all kind comments - I don't see a need for any more paraphanalia - just sit with the engine revving at 2500 rpm for 5 minutes til the stat opens twice a year if your worried.....................

[Doone]

No you don't need any more special kit.

[missfixit70]

I'd agree with the above, new stat if there's any doubt, or even if there isn't, proper flush, have the temperature gauge resensitised (either by the Mason alarm or the mod that requires a resistor & a bit of dismantling & soldering) so you know what's happening, low/hi coolant alarm & if you're curious about what the actual temperatures are doing then a TM2 or other temperature gauge.

[Grahame at work]

Excellent debate

Dandy’s text is good (as his input usually is) but my view differs slightly.

In my experiments in my last Bongo I concluded that the system works in a ‘balanced’ condition. That is it is a classic control system and operates at a predetermined nominal condition. This is with the stat in a mid position that is part open (or part closed if you like) so that the block/head temperature can be maintained at its design optimum.
So with increased load (up hill etc.) it can use more radiator flow to cool and with decreased load (down hill etc.) it can decrease the radiator flow to prevent too much cooling of the block/head.

Its taken all my lunch time to work through this thread so I’ll have to add the more details I have when I get home.

Be back later
Grahame

[missfixit70]

Excellent debate

Dandy’s text is good (as his input usually is) but my view differs slightly.

In my experiments in my last Bongo I concluded that the system works in a ‘balanced’ condition. That is it is a classic control system and operates at a predetermined nominal condition. This is with the stat in a mid position that is part open (or part closed if you like) so that the block/head temperature can be maintained at its design optimum.
So with increased load (up hill etc.) it can use more radiator flow to cool and with decreased load (down hill etc.) it can decrease the radiator flow to prevent too much cooling of the block/head.

Its taken all my lunch time to work through this thread so I’ll have to add the more details I have when I get home.

Be back later
Grahame

Isn't this basically how Dandy described it anyway? It's certainly my understanding of how it works, just a slightly different way of saying it?

[mikexgough]

Excellent debate

Dandy’s text is good (as his input usually is) but my view differs slightly.

In my experiments in my last Bongo I concluded that the system works in a ‘balanced’ condition. That is it is a classic control system and operates at a predetermined nominal condition. This is with the stat in a mid position that is part open (or part closed if you like) so that the block/head temperature can be maintained at its design optimum.
So with increased load (up hill etc.) it can use more radiator flow to cool and with decreased load (down hill etc.) it can decrease the radiator flow to prevent too much cooling of the block/head.

Its taken all my lunch time to work through this thread so I’ll have to add the more details I have when I get home.

Be back later
Grahame

Isn't this basically how Dandy described it anyway? It's certainly my understanding of how it works, just a slightly different way of saying it?

As I see it......yes exactly the same but worded differently......

[dandywarhol]

Excellent debate

Dandy’s text is good (as his input usually is) but my view differs slightly.

In my experiments in my last Bongo I concluded that the system works in a ‘balanced’ condition. That is it is a classic control system and operates at a predetermined nominal condition. This is with the stat in a mid position that is part open (or part closed if you like) so that the block/head temperature can be maintained at its design optimum.
So with increased load (up hill etc.) it can use more radiator flow to cool and with decreased load (down hill etc.) it can decrease the radiator flow to prevent too much cooling of the block/head.

Its taken all my lunch time to work through this thread so I’ll have to add the more details I have when I get home.

Be back later
Grahame

Thats exactly how I see it Grahame - maybe my ramblings lost their way along the line.............

still waiting for TGP to chip in with his wisdom - then the merry widdow can get on with the drawings

[widdowson2008]

Excellent debate

Dandy’s text is good (as his input usually is) but my view differs slightly.

still waiting for TGP to chip in with his wisdom - then the merry widdow can get on with the drawings

All I asked for from the beginning was a Cooling system diagram and it looks as if that is going to happen.
Still want it, but am very happy to wait until the guys who Know about these things have ironed out the very small bits and got it to a definitive state. Then FULL PRODUCTION begins.
I have been amazed at the response.
It would appear that others are interested in the same thing having looked at the number of hits this topic has taken.
When this is finally complete, I will reveal the extent of the graft involved, especially in the background out of site by the 'think tank'. Don't want to embarass folk by naming names, but you know who you are.
Thank you very much for your efforts

[Allans]

Where's Allan when you need him ???......give him a dig Doone !!! Thanks

Nice one Haydn. I took photos of the thermostat. My daughter loaded them onto my website.

Sorry I don't have time to look at the diagrams and posts here.

One thing I can offer. I don't know if it's been done; has anyone measured the heat transfer along the hoses/pipes etc?
As a way of investigating the coolant path/travel (from cold).
If anyone would like to do this, you are welcome to use my workshop, ramp and heat sensor, at your own risk of course.
Any day except Sunday of course. I'd have to book you in, to make sure you had the space/time needed.

If you'd like to give it a go, give me a shout.
Allan.

[Grahame at work]

Sorry Dandy if I thought we were out of step - I see it as a dynamic control system and I think its just my terminology that's different

Anyway I have gone over my old posts and off line discussions with Aetherlic and have gathered some of my ramblings on the subject. Also sketched up a thermal / flow schematic and have decided that I want to spend a bit of time refining it in line with my earlier ramblings before publishing.

Please bear with me
Will be back again tomorrow night

Regards Grahame

[haydn callow]

4.20 am I know ...sad.
Just want to jot down my understanding of the cooling system.

It is 2 systems....a small bore heating/cooling system SB
and
A large bore cooling system LB
these are linked together at the stat like a mixer tap.

Early morning = cold Bongo
SB circuit fully open LB closed tight.
off we go and the coolant heats up quickly and is pumped around the SB circuit and gets the heaters nice and hot and in doing so loses a lot of heat and this is enough to keep the engine happy under normal running conditions..

We open Bongo up a bit on the motorway or tow the shed along...SB no longer keepingn up with the cooling requirements and the Stat starts to open (mixer tap)
Stat opens a third to halfway and then radiator is brought into use...cooling things down and at the same time heating the cabin. This is as hot as it should get and everything is fine.

Now the bad news....Our Bongo has a half blocked rad or there is some other fault in the system....Stat fully opens and this shuts off the SB circuit......cabin heaters start blowing cold (no...not a air lock) co's no SB circulation...Rad cannot cope with the extra cooling requirements and we are now in a irreversable meltdown.

This all now makes sense to me and a lot of the old info is out of the window.......i.e. heaters blowing cold was always put down to air locks....
I also belive the pump pumps the coolant round the SB circuit all the time, right from the off.

From the above I would guess that the stat never fully opens in a good cooling system, half open is plenty and should it ever fully open we are in trouble,,

Thoughts anyone??

[haydn callow]

Having just read Dandy's post again....Most of my ramblings mirror what he suggests....just a couple of detail points...

It would also seem that there comes a point when turning on the blowers becomes pointless, as there is no circulation in the SB system.

It would be nice to have a gadget that told us the %'age the stat is open......this would give us a indicator to the cooling systems condition.

[mikexgough]

4.20 am I know ...sad.
Just want to jot down my understanding of the cooling system.

It is 2 systems....a small bore heating/cooling system SB
and
A large bore cooling system LB
these are linked together at the stat like a mixer tap.

Early morning = cold Bongo
SB circuit fully open LB closed tight.
off we go and the coolant heats up quickly and is pumped around the SB circuit and gets the heaters nice and hot and in doing so loses a lot of heat and this is enough to keep the engine happy under normal running conditions..

We open Bongo up a bit on the motorway or tow the shed along...SB no longer keepingn up with the cooling requirements and the Stat starts to open (mixer tap)
Stat opens a third to halfway and then radiator is brought into use...cooling things down and at the same time heating the cabin. This is as hot as it should get and everything is fine.

Now the bad news....Our Bongo has a half blocked rad or there is some other fault in the system....Stat fully opens and this shuts off the SB circuit......cabin heaters start blowing cold (no...not a air lock) co's no SB circulation...Rad cannot cope with the extra cooling requirements and we are now in a irreversable meltdown.

This all now makes sense to me and a lot of the old info is out of the window.......i.e. heaters blowing cold was always put down to air locks....
I also belive the pump pumps the coolant round the SB circuit all the time, right from the off.

From the above I would guess that the stat never fully opens in a good cooling system, half open is plenty and should it ever fully open we are in trouble,,

Thoughts anyone??

That sums it up in a non techie way and how my system works to a tee.....
Like the idea of a gizmo but how would it work?.....how would it fit, outside they system like TM2 or inside the cooling circuit?
Now..... if the cooling system is running as described....... how often will the radiator fans come into play..... not often I suggest....prepared to be shot at dawn for making such a suggestion...

[haydn callow]

I think that particular gizmo (stat opening detector) is a pipe dream..However I have come across a temp monitor which will give 3 seperate temp displays from 3 unconnected sensors....I will fit this and have a play in the near future.
As Dandy has pointed out.....once the system is understood extra bits and bobs should really not be required. What is already available should be plenty and I now belive the condition of the radiator is critical....It has to do it's job when called upon or things rapidly go wrong.