OK...

as some of you knwo I had a nightmare with overheating during my SVA yesterday...

so, here is a quick diagram of my system, question is - what did i get wrong?

it cools fine when you keep above 40mph but when staionary it boils over in a couple of minutes!




Description

As you can see it is a very simple system with the highest point on the top hose having a T piece with a 15mm hose coming off that back to the header tank (goes through a 8mm ish restrictor)

fan is a fairly cheap one but it is sucking air through the rad as it should... however the vanes were not reversible so it is not 'optimal'....

All - sensible - ideas welcomed....

I have read the thread from the robin hood owners forum about this sort of thing but can't see how i can apply that logic to this as the rad doesn't have an overflow...

[Edited on 9-5-08 by DaveFJ]

At first sight if it's ok when you are moving, it would be inefficient fan.

However, do you not have water circulating via the inlet manifold ?

The small one from my pump goes to the inlet manifold (via the heater if there were one) and the bottom of the header tank is taken from a T on the lower radiator hose.

See attached diagram. This is the system i use. You dont appear to have a take off from the manifold around to the back of the engine to the water pump.

HTH

Nige

Where is you fan Switch - Should be upstream (rad side ). thermostat .

Is you fan running ?

How big a fan you got and is it rear or front mounted.

Is the fan running in the right direction?

Does you fan run on when the engine is shut down (perm live not ign Live)?

What temp does you fan come in at ?

Is your pump working

Is your pump working in the correct direction?





My zetec will boil if the fan doen;t come on but will be ok if the fan starts - I don;t have a header bottle.

[Edited on 9/505/08 by mad4x4]

You need a by-pass connection or the engine will over heat before hot coolant can warm up the thermostat enough to open.

On 1970s Fords the by-pass flows through the heater matrix which runs hot all the time. If you remove the heater or fit a heater with a water valve you must fit a by-pass connection between the head (before the thermostat) to the water pump inlet or bottom radiator hose.



[Edited on 9/5/08 by britishtrident]

quote:

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Originally posted by cryoman1965
See attached diagram. This is the system i use. You dont appear to have a take off from the manifold around to the back of the engine to the water pump.

HTH

Nige

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I had heared that but general overwhelming consensus was that it qwasnt needed based on the principle that if the water is below the operating temp then the engine cant be hot enough to worry about! I know a LOT of people dont bother with any take off from the manifold - even if id did have room to fit one! - I don't


fan is working properly and comes on @86 degrees. runs on after the engine stops. can't see how the mechanical pump can work backwards?

As I say - cooling is fine when moving and it is only when it is staionary that it overheats. therefore I don't think it has anything to do with the thermostat (that opened long before)...

think I am going to try making some ducting around the fan so that it sucks air all across the surface of the rad.... maybe uprate the fan as well...

now SVA is sorted i am also going to fit bonnet vets to get some extra engine bay cooling, but that is pretty irrelevant when stationary anway....

My oil cooler matrix is in front of the rad so i may have to consider moving that out of the way....

You need to lose one of the pressure caps (the one on the radiator, replace it with a solid cap) Also for on the move make sure you duct all the air through the rad rather than let it go by.

[Edited on 9/5/08 by phoenix70]

Check you have the thermostat in the right way round and while you have it out drill a couple of extra 3mm holes in the flange to let the air up to the header tank. I have a manifold connection on mine and I haven't seen one without but if it works then that's o.k. but where does the hot water trapped in the head go.

The vflow through the head via the inlet manifold is very important, large heat differentials will cause problems with excessive local area hot spots

i am having the some trouble with my pinto engine getting to hot when moving as well as it sitting still
my pipe layout if different will this be the problem that mines over heating??

as i understand it the flow through the head ,once the thermostat is open, has very little to do with the take off for the heater matrix.....

of the water flowing into the head only a little could be travelling down the small pipe to the heater anyway, therefore the rest of the water must flow through the galleries. when you think about it there are several water channels surrounding each cylinder and these allow the water to flow from the head to the block (I think thats the direction of flow?) thern the water thravels down through the block into the pump and goes out to the rad and back round to the head again... the way i see it that means by blocking the heater take off you actually improve the coolant flow to the head....

I think my problems are little to do with that - although i am going to try removing my thermostat and see what happens.... If my problem was down to coolant flow through the engine then surely it wouldn't cool efficiently at 30-40mph.......?

quote:

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Originally posted by mat.price
i am having the some trouble with my pinto engine getting to hot when moving as well as it sitting still
my pipe layout if different will this be the problem that mines over heating??

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the small pipe from the thermostat is the some size as the header tank piper my header tank is from tiger

must be a different housing to mine - no small pipe on there...

OK... just been checking.... and I am wrong!

the flow is in the opposite direction... from the pump into the block and up through the galleries to the head then back out of the top hose to the rad (bleed back to header tank at highest point of hose) from the bottom of the rad back to the pump with the header tank also supplying the pump...

all seems logical to me!

You should not have a take off from the thermostat housing this out let would have been for a temprature sender.

quote:

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Originally posted by ragindave
You should not have a take off from the thermostat housing this out let would have been for a temprature sender.

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Here is a photo of my efi and cooling.....as you can see my heater take off i have done with copper piping which goes to the other side of the engine. This piping also has a T piece that goes to the bottom of the expansion tank. The radiator bottom house connects under the alternator (just below the heater connection at the front of the engine).
The top expansion pipe goes along the rocker cover and joins the pipe going to the top of the rad.....


engine bay
HTH

regards

TimR
timr.spaces.live.com

Thats right the senders are in the block but some after market thermostat housing are sold with a thread insert iI thought it may be one of these

Mine is piped up the same as yours Dave and I dont have any problems.

If you are coming to the diss meet on sunday feel free to have a look at my system.

My fan is on a manual switch. I leave it running all the time once the water temp reaches approx 80deg. I also replaced the stat with an 82deg one from a fiesta instead of the 88deg standard pinto one.

Cheers,
David

Hi this is how i have mineits been like this for 5 years

bottom rad to water pump
top rad to thermostat
out inlet manifold to top of header tank
bottom of h/ tank to 5/8 pipe on water pump
the header tank is a ford tank with a top that lets air in and out
i have no thermostat fitted
Jacko

quote:

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Originally posted by DaveFJ
as i understand it the flow through the head ,once the thermostat is open, has very little to do with the take off for the heater matrix.....

of the water flowing into the head only a little could be travelling down the small pipe to the heater anyway, therefore the rest of the water must flow through the galleries. when you think about it there are several water channels surrounding each cylinder and these allow the water to flow from the head to the block (I think thats the direction of flow?) thern the water thravels down through the block into the pump and goes out to the rad and back round to the head again... the way i see it that means by blocking the heater take off you actually improve the coolant flow to the head....

I think my problems are little to do with that - although i am going to try removing my thermostat and see what happens.... If my problem was down to coolant flow through the engine then surely it wouldn't cool efficiently at 30-40mph.......?

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Are you sure your fan is blowwing in the correct direction, it sounds to me as if it is blowwing through the rad from behind and at low speeds there is no cold air going through the rad but at higher speeds the air is being forced through by the movement of the car.

OK.. been testing... replaced the stat - coz it was cheap and thought what the hell!
re-routed the pipe from the bottom of the header tank to the pump so that it didn't loop upwards so much...

ran it and it did get hot... at about 110 degrees i started to see some steam venting from cap. stopped the engine and both pressure caps blew in a spectacluar manner! proper fountains of boiling water going up about 10 feet

fan kicked in as it should at about 87 degrees or so and was working properly pulling loads of air through the rad...

fan carried on for a few mins after swithing engine off - as expected....

so why is my cooling so crap?



we have had the arguments about the manifold take off but that is just at warmup so irrelevant really... I know loads of others use the polo rads so where have i gone wrong?

should i invest in an electric water pump?? at least it would run on with the fan after switching off...?

Not quite the same situation, but I had a few hot-water fountains with my crossflow - entirely due to airlocks. I don't know what the Pinto is like, but the crossflow is a real pig to clear when it's in a bad mood.

your on the some boat as me
so i looked at my old cortina book for over heating

cause/-insufficient water in cooling system
remedy/-top up rad (last time i put the water in it was to the top)

cause/-fan belt slipping
remedy/-tighten fan (had a look it was ok)

cause/-radiator core blocked or rad grille restricted
remedy/-reverse flush rad,remove obstruction (i have a new polo rad and it fits a treat)

cause/-thermostat not opening properly
remedy/-remove and fit new (i pulled it out today so i have no thermostat this did help when driving around then it over heated so i stop to let it cool)

cause/-ignition advance and retard incorrectly set
remedy/- check and reset timing (this was done on the rolling road)

cause/-carburettor incorrectly adjusted
remedy/-tune carburettor (done on rolling road)

cause/-oil level in sump to low
remedy/-top up sump to full mark on dipstick (i did that before i started the pinto)

cause/- engine not yet run-in
remedy/-run-in slowly and carefully (my enigne was made in 1988 think it will be run in by now?)

which leave me with one thing that i have not looked at?
cause/-blown cylinder haed gasket ie water/steam being forced down the rad overflow pipe under pressure!!
remedy/-remove cylinder haed, fit new gasket
im thinking of doing this next monday and see if it makes any difference!!
that im out of options i dont know

we have had the arguments about the manifold take off but that is just at warmup so irrelevant really... Is it? To my way of thinking the manifold is the highest point of the cooling system on the engine side of the thermostat, having a hose here would help to bleed the system.

should i invest in an electric water pump?? at least it would run on with the fan after switching off...?

IIRC when I was running a Pinto the exit from the head in the middle of the inlet manifold is at one of the highest points of the engine so would let air out.
Try jacking the rear of the car up as high as you can also lift the header tank as high as possible to get as much air out as poss.

Oh and get rid of the pressure cap on the rad as that lets the system draw in air as it cools.

[Edited on 10/5/08 by Schrodinger]

Bypass is not for just at warm up if you don't have it the cooling system won't work properly.

By pass is essential to get an even spread of temperature through the engine.

See http://web.tiscali.it/elise_s1/CIB.htm

[Edited on 10/5/08 by britishtrident]

Anyone know where I can get a non-pressure relief type rad cap for my Polo rad?

A lot of people have suggested I need to loose the cap in favour of a blank cap but I can't find one

Polo rads dont have a cap on...AFAIK. Mine hasnt anyway.

David

quote:

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Originally posted by DaveFJ
Anyone know where I can get a non-pressure relief type rad cap for my Polo rad?

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