Cooling system principles

alanm · March 25, 2011, 01:34:52 PM

Hi All

I am going to replace the factory expansion tank in my GTV6 with an aluminum tank and have been considering 2 options:

The International Auto Parts part that replicates shape of factory part (tried and tested by members of this forum) or
a generic item (see attached photo). The generic item is about 30% the cost of the IAP item.

I want to know if the generic item is an option, ASSUMING that it will fit in the engine compartment in the same space as the factory part.
What are the cooling system principles?
Question 1. Does the upper part of the tank need to be located higher than the upper most point of the cooling system of the motor?
Question 2. How do you know what the capacity of the tank needs to be? I reckon the factory part holds about 1.5 litres and I keep it about half full. I guess this means it can cope with .75 litres of expansion (never seen this happen).
Question 3. Does it matter if the tank is mounted on an angle provided the tank cap/opening is well above the fill mark?

Cheers
Alan

alanm · March 27, 2011, 12:36:25 PM

I have done some more investigation, the tank pictured in my last post will not fit in the same space as the factory part, however a 210 x 100 cylindrical tank offered by the same company will fit.

HOWEVER... the factory part has one 18mm inlet pipe and THREE 6mm outlet pipes, the generic alloy tank has one 18mm inlet pipe and only TWO 6mm outlet pipes. There is no provision for the 6mm outlet pipe that goes to a T piece at the rear of the motor (connects to the heater hose?).

SO... rather that remove the T piece and modify the cooling system which might be asking for trouble, I think I might just order the IAP tank and be done with it.

Cheers
Alan

MD · March 27, 2011, 08:00:59 PM

One important oversight.

In an opaque plastic tank, you can see at a glance whether it needs a top up or not.

AlfaACT · March 27, 2011, 09:53:17 PM

Quote from: MD on March 27, 2011, 08:00:59 PM
One important oversight.

In an opaque plastic tank, you can see at a glance whether it needs a top up or not.

"opaque", no! Translucent maybe?

MD · March 28, 2011, 10:07:36 AM

Would you setle for splitting the difference ie transpaque ?

;

AlfaACT · March 28, 2011, 12:41:01 PM

Quote from: MD on March 28, 2011, 10:07:36 AM
"...transpaque..."

hmm, in this particular situation it's probably pretty apt

alanm · April 20, 2011, 12:57:23 PM

Hi all,

Fitted the International Auto Parts aluminum tank and I am very happy with the results!
Look great and fits nicely though you do need to drill one hole.

I replaced all of the hoses that connect the tank with the rest of the cooling system, the original hose that went from the tank to the left side of the radiator had hardened so much that it could be snapped like a twig!! Replacing the hose from the tank to the T piece at the back of the motor involved skinned knuckles and some swearing.

The sight tube however lets the quality of the tank down, a real weakness in the whole cooling system. I have temporarily replaced it with black heater hose.
I am planning to replace this with reinforced clear compressor hose (or maybe fuel line). Though its not a deal breaker, it is nice to see the coolant level without taking the cap off.

Oh, one more thing. If you do order a IAP tank, get the IAP cap at the same time. The cap I was using on the old plastic tank does not fit.

Cheers
Alaln

Cool Jesus · April 21, 2011, 10:06:09 PM

So we get a photo of the unit that won't fit, but not of the actual unit that does and in situ? Where's the pic?

alanm · May 14, 2011, 06:45:40 PM

Pictures of end result attached.

I have temporarily replaced the clear sight tube (not up the job) with black heater hose.
Some clear hose I bought from a hardware store will go in for a test. Its thick, reinforced with fibre and rated to 120PSI. Could be designed for very hot water going in or out of a dishwasher? Will report back on that one.

Whilst replacing the hose that goes from the rear of the expansion tank along the firewall I noticed that the old one had been fouling the windscreen wiper mechanism. You might be able to see that I have moved it out of the way with a plastic tie (gotta love those things)

Cheers
Alan

grpa9x · June 02, 2011, 09:06:59 PM

hi alan,
they are a good fit , i fitted the same unit a while ago and had no problems except one hole didnt line up, a side note your engine bay looks excellent.
cheers michael

Mike · August 25, 2011, 01:19:11 PM

Looks good. I'll add that installed the first header tank shown and it took a while to discove a rather annoying feature. The supplied radiator cap does not seat properly. In my case it missed the seat by 1mm whenn compressed. Something to look out for as it will leave to misterious overheating (which you would be able to detect by doing a cooling system hot pressure test).

Cheers
Mike

Gary Pearce · August 25, 2011, 01:50:13 PM

Nice looking tank. What did that cost?

alanm · September 08, 2011, 01:50:36 PM

Hi all,

Sorry I have been a bit slow replying to comments, jumped ship into the 160 series forum for a while there!

Gary the tank is US$219.00 and about $50 for delivery if I remember correctly. Good value I think, though that issue with the sight tube needs to be better resolved by IAP. My fix with the braided dishwasher hose (if that is what it is) has proved to be a good one.

Michael, thanks for your comment re. the engine compartment, it does spruce up rather well!

Cheers
Alan