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Posted: Wed Mar 26, 2008 11:55 pm
by haydn callow
What we need to do is get hold of a old retired Bongo and systematically pull the whole cooling system to pieces.
I think the factory stat does when it opens shut off the bypass. I will confirm/or not, this but this will all take time.
I still go back to my own view that..if your cooling system is in good condition then it is well up to the job required of it. They do seem to last 100,000 min miles with regular maintainance and they are 10/12 years old.
Posted: Wed Mar 26, 2008 11:57 pm
by lizard
The Great Pretender wrote:bigdaddycain wrote:The Great Pretender wrote:
Am I on another planet bdc? need normal

people understanding this to, how can I help?
Let's put it this way Mel, if i looked at a schematic of the bongo's cooling system for long enough, i'd be inclined to put my hands over my ears,and start singing la la very loudly before my simple noggin overheated!
I won't pretend to understand the complete ins & outs of the cooling system, i can follow some of it, to a point...

OK will try to explain it at Charity farm if I dont get locked out.

I hope all the experts can sort all this out, then make an anti-overheating device kit that I, chief numpty can fit to the jolly old Bongo and fill me with confidence. I get worried every time I drive it, even with all these alarms and hoses, water pump, pipes, new cyl head and engine flush that it has had.

Posted: Thu Mar 27, 2008 1:06 am
by dandywarhol
I'm listening and taking in what you're saying about the pressure at the water jackets TGP but wondering how the temperature in the hottest part of the system (the area around where the temp gauge sender is) is still around 90 deg.C at 20 odd psi

Posted: Thu Mar 27, 2008 1:15 am
by The Great Pretender
dandywarhol wrote:I'm listening and taking in what you're saying about the pressure at the water jackets TGP but wondering how the temperature in the hottest part of the system (the area around where the temp gauge sender is) is still around 90 deg.C at 20 odd psi

Just sent u a message on this post.
dandywarhol wrote:
Apart from the "sniffer" test with a gas analyser another method to test for a head gasket/cracked head is to use a cooling system pressure tester but instead of pressurising the system to check for a leak, run the engine to see if cylinder pressure is going into the tank, if it is it will show on the pressure gauge.
Intresting, can you explain more Dandy?
Posted: Thu Mar 27, 2008 1:24 am
by The Great Pretender
Ok got your post on that thread.
Posted: Thu Mar 27, 2008 1:27 am
by The Great Pretender
So Dandy what happens to the pressure on a standard Bongo system. If you have the test gear to help us are you going to?
Posted: Thu Mar 27, 2008 1:30 am
by Aethelric
The Great Pretender wrote:Aethelric wrote:I love this thread
Where can I find the full size picture of the coolant system so I can try to find out what everyone is talking so eloquently about.
Dave
http://www.lushprojects.com/bongoparts/pages/

Good grief, is that all there is? I am beginning to understand the problem.
Dave
Posted: Thu Mar 27, 2008 1:33 am
by The Great Pretender
Aethelric wrote:The Great Pretender wrote:Aethelric wrote:I love this thread
Where can I find the full size picture of the coolant system so I can try to find out what everyone is talking so eloquently about.
Dave
http://www.lushprojects.com/bongoparts/pages/

Good grief, is that all there is? I am beginning to understand the problem.
Dave
Yep and the more you find out the less you know.

Posted: Thu Mar 27, 2008 1:39 am
by dandywarhol
The Great Pretender wrote:So Dandy what happens to the pressure on a standard Bongo system. If you have the test gear to help us are you going to?
I've access to the gear at college and will be testing it when we start back.
I'm off to the Outer Hebrides on Friday for a week, so I'll be out of contact with the abnormal world for a bit

Posted: Thu Mar 27, 2008 1:46 am
by The Great Pretender
dandywarhol wrote:The Great Pretender wrote:So Dandy what happens to the pressure on a standard Bongo system. If you have the test gear to help us are you going to?
I've access to the gear at college and will be testing it when we start back.
I'm off to the Outer Hebrides on Friday for a week, so I'll be out of contact with the abnormal world for a bit

Thats great, have fun and enjoy.

Posted: Thu Mar 27, 2008 9:54 pm
by haydn callow
TGP...How confidant are you that the pressure reading you are getting 8/9 inches along the top hose from the engine is accurate ?? 21psi+
Why would the pressure further along the same hose towards the rad be very much less ? I am getting 3.8psi at the rad cap at 88C, revving seems to make little differance.
My rig is a bit agricultural.
Posted: Thu Mar 27, 2008 10:28 pm
by The Great Pretender
haydn callow wrote:TGP...How confidant are you that the pressure reading you are getting 8/9 inches along the top hose from the engine is accurate ?? 21psi+
Why would the pressure further along the same hose towards the rad be very much less ? I am getting 3.8psi at the rad cap at 88C, revving seems to make little differance.
My rig is a bit agricultural.
Im totally confident, and thanks for testing it. Have you heard of Bernoulli's principle ? And how a venturi works?
Posted: Thu Mar 27, 2008 10:37 pm
by haydn callow
Yep !! I was involved in the development of a "!improved" venturi years ago.
We incorperated a aerofoil section into a water pipe and put a small air pipe into it which was open to the air outside. Works much better than a restrictive venturi and has now been taken up on foam hoses on fire engines.
I was intended it to airate Koi ponds which it did very well.
Posted: Thu Mar 27, 2008 10:47 pm
by The Great Pretender
Ok, so by putting the stat on the outlet allows the pump to build pressure, when the coolant goes through the restriction (stat) the pressure is lost, as you know the increase in speed though the restriction reduces pressure.
Posted: Thu Mar 27, 2008 10:57 pm
by The Great Pretender
What side of the aerofoil was the pipe comunicating with?