Clearing out the side bumper to ease IC flow and pulled off the rad overflow tank!

 

Couldn't see any way for ditched water to return to the rad is this the case, then I can just not put it back in?

I think when the engine gets hot and the water expands it dumps excess into the tank, likewise the reverse is true when it cools the water contacts causing a vacum which sucks water from the tank back to the rad, dont think you can do without it?:confused:

 

If you ditch the tank you'll have to plug the hole that the pipe goes to on the top of the rad, if you do that there will be no where for the water to go so it will probably eventually force the rad cap to leak or maybe somewhere worse!! Likewise when it cools it will try to suck air in through the same place.

 

Least thats my theory anyway!!!:confused:

Cheers Mate!

 

I can see your point of view!

 

I don't have to plug the overflow hose from the rad cap, I can just run a length of hose to the floor, like older cars, I am of course too young to remember this!

 

I believe on some systems they do suck the coolant back into the car, but on the Zed I cannot see where this can happen!

I believe on some systems they do suck the coolant back into the car, but on the Zed I cannot see where this can happen!

 

It must do. Why else would Nissan put a level indicator on the overflow tank dipstick unless there was a recommended correct level. Also too much and it overflows the expansion tank anyway.

 

This seems to me the reason why the level in the rad is always in the neck of the filler right to the top - it keeps itself topped up by sucking water back from the expansion tank when it needs to. You find that the rad cap can have a valve on it for sucking back - tho cant say I had a good look at it.

Sureley if the radiator sucks it back from the expansion tank the tube will attach at the bottom of the tank, if it only dumps into it and doesnt suck it back the tube will attach at the top.

 

I think it attaches at the bottom, but mark should be able to tell us seeing as hes pulled his off!!!

No this one is staying off, fitting a smaller model to ease flow through the intercoolers!

 

Found out the rad cap allows water to be sucked back in when a vacuum occurs, cheers guys!!!!!!:D

I've been thinking to reposition the tank to the area where the AIV valves and vacuum tanks of the clutch used to be (on my LHD car at least), which is behind the fender.

Probably need another (shape) tank though and filling the tank could be a little difficult, but at least it no longer blocks airflow through the ic.

 

Another possibility would be to use a similar tank as is used for the headlight nozzles on EURO/UK spec models, but this probably only works if you still have a stock(ish) frontbumper.

 

Or... get one of those huge front mount intercoolers ! :D

 

-Eric

How easy is it to drain the overflow tank - is there a tap to open? Is it easy to get to and do you have to remove the plastic inner wheel arch to do it?

 

Cheers.

It's behind the plastic inner wheel arch and there is no drain plug, but you can use the small hose that runs to the radiator to drain it.

Is it easy to take the tank out as I want to clean it out and flush it through.

yes, you'll need to remove the wheel and loosen the plastic inner wheel arch (no need to completely remove it)

 

As far as I can remember the tank itself is held by 3 or 4 bolts that are pretty easy accessible

Be careful that you are not taking this improved airflow thing to extremes. Just because you have say 300 cm2 of IC area it doesnt mean you need you need 300 cm2 of airflow before and after the IC. In fact too much can actually cause turbulence and slow the through air flow. The obvious example of good airflow to a radiator is the E type jag. There you have the small oval mouth and the big radiator well behind it. This gives optimum airflow through the rad fins.

 

On the zed there is also the venturis on series 2s that are designed to drop air pressure behind the ICs so as to pull air through them. These are simple add ons if you dont already have them.

 

You'll be fitting small electric fans behind each IC now wont you ;)

No venturis on my series two:confused:

 

It is very restricted down there and trying to tidy things up, quite a few people have done it in the states. One of the problems is that there is a difference on the charge temp between the different IC's, hopefully this will improve flow and equalise the temp more!

All,

As per B9irks suggestion this is needed! Its an 'expansion' tank not an overflow tank!

 

When the system runs hot and 'expands' water is pushed to the top of the rad and out through the hose to the tank. When it cools and contracts it sucks it back in.

 

Had mine off in the rain last night as i've major cooling trouble at the mo and the level on mine is up and down like a yo-yo! Think i have an airlock/ water leak and took it off to clean it up and monitor it more effectively.

Guyz , your engine needs this fluid ,so make sure if you change the over flow tank ,you can get the same amount of water discharged and then drawn back in to the engine when needed,otherwise with the increased heat in the engines,,you have caused through tuning your engines,eg turbo,more psi => more heat ,,you could blow the head gasket,,,you`ll need that cooling system even more,, so be careful..

:slap: :slap:

bad airflow through intercooler(s) is just as bad...maybe even worse for cars running high boost

maybe this is an idea ?

 

http://twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1050916

Blue Peter always used either a squeezy bottle (washing up liquid for you young uns) or a toilet roll tube. For this one the squeezy bottle looks like the solution! :)

 

Heck its Monday and not such a daft idea