plumbing question

72RSbug Officially Full-On Dubber

266 posts · joined Jan 2005 · 25 Aug 2008, 10:54 pm

#665989

This might sound silly but I forgot which coolant lines goes where on the radiator when using a flat-4 suby engine.

Is it bottom part on the engine to bottom part on the radiator or reversed?

Thanks

Brad Wolfsburg Elder

3,764 posts · joined Aug 2002 · 25 Aug 2008, 11:19 pm

#665991

Bottom part of engine to bottom part of radiator.

Think of it this way.. the bottom water inlet on the engine is the draw side of the water pump so you want water there all the time, thus the bottom of the radiator feeds it so it has the best chance of there being water there for it.

Brad
Why copy when you can own an original ?
Meyers Manx Australia

72RSbug Officially Full-On Dubber

266 posts · joined Jan 2005 · 26 Aug 2008, 12:01 am

#665995

Thanks, figured it was that way but the place of the thermostat made me doubt and I don't have my old radiator anymore to check how things used to be hooked up.

ricola Wolfsburg Wizard

437 posts · joined Feb 2003 · 26 Aug 2008, 12:49 am

#665999

For some reason Subaru put the thermostat on the inlet. I will be relocating it to the outlet as most other engines, that results in a more stable operating temperature and it is much easier to bleed the system among other benefits...

http://www.ricola.co.uk

72RSbug Officially Full-On Dubber

266 posts · joined Jan 2005 · 26 Aug 2008, 12:59 am

#666000

just to make sure, the spring that's on the thermostat goes towards the water pump side. correct?

rocknrob Insano Dub Head

844 posts · joined Dec 2003 · 26 Aug 2008, 6:11 am

#666007

ricola wrote:For some reason Subaru put the thermostat on the inlet. I will be relocating it to the outlet as most other engines, that results in a more stable operating temperature and it is much easier to bleed the system among other benefits...

how are you going to do that? thats interesting becos my radiator is way up the front of the kombi so by the time it gets to the thermostat it must be a lot cooler😠

Brad Wolfsburg Elder

3,764 posts · joined Aug 2002 · 26 Aug 2008, 9:32 am

#666026

72RSbug wrote:just to make sure, the spring that's on the thermostat goes towards the water pump side. correct?

yep from memory.

Just look at it and see which way it opens, water will be traveling up so it will need to open with water flowing up.

Subaru put the thermostat in before the water pump because the system is a "Sip" design rather than a Fully Open design, it is designed like this to keep the operating temp as constant as possible.

If the thermostat was on the other end then it would be harder to regulate with a "Sip"

Brad
Why copy when you can own an original ?
Meyers Manx Australia

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 · 26 Aug 2008, 9:51 am

#666030

Hi

The cooling system also has a natural thermo siphon as well, the hot water goes to the top, cool water falls to the bottom, so even with the motor stopped after running the water will still slowly circulate.

That's why its best to mount cooling fans near top of the radiator.

Steve

ricola Wolfsburg Wizard

437 posts · joined Feb 2003 · 28 Aug 2008, 5:49 am

#666361

That's exactly why I will be relocating the thermostat, the stock bypass flow on its own struggles to maintain the stat bulb at the real operating temperature which results in a delay of it opening, this is exaggerated when used in mid/rear conversions like these. With the stat on the outlet there is never any worry of it seeing the correct temp as pretty much all the flow is forced past it. It's fairly easy to convert, just cut the centre out of the stock stat and use an external one on the main engine outlet (I have used a BMW E30 4 cylinder one), also block the stock heater supply pipe and use the new stat bypass for the heater supply. Depending on year of the engine you may have to restrict some original bypass lines.

In the UK the K series engine suffers badly from this problem, Land Rover even supply a factory kit to convert to external stat on the outlet! I also did the conversion on my last kit car which used a K series mid-mounted like the Lotus Elise and it worked a dream. With that engine it was even worse as the return was to the aluminium head which resulted in nasty thermal shocks as the thermostat cycled and one of the reasons for the engine's apetite for head gaskets...

rocknrob wrote:
ricola wrote:For some reason Subaru put the thermostat on the inlet. I will be relocating it to the outlet as most other engines, that results in a more stable operating temperature and it is much easier to bleed the system among other benefits...
how are you going to do that? thats interesting becos my radiator is way up the front of the kombi so by the time it gets to the thermostat it must be a lot cooler😠

http://www.ricola.co.uk

rocknrob Insano Dub Head

844 posts · joined Dec 2003 · 28 Aug 2008, 8:07 am

#666377

👍

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 · 28 Aug 2008, 8:51 am

#666384

Hi Ricola

Do you have a photo of the BMW thermostat?

Steve

ricola Wolfsburg Wizard

437 posts · joined Feb 2003 · 28 Aug 2008, 10:36 pm

#666514

Here you go:

Also here's a diagram I did for the Libra's conversion:

I'm guessing all this isn't such a problem for you guys but in cooler climates it is. A lot of the Canadian vanagon guys use a thermostat spacer, that brings it further away from the cold return and lets the bypass work a bit better.

http://www.ricola.co.uk

GeorgeL Officially Full-On Dubber

231 posts · joined Feb 2006 · 2 Oct 2008, 4:15 am

#672608

This has been discussed on and off and various reasons speculated for the oddness of the Subaru setup. The intent seems to be to get heat to the heater core as rapidly as possible, since the heater core always sees full flow.

Various setups have been suggested for an outlet thermostat. the simplest was just a couple of Chevy thermostat covers placed together with a thermostat between and placed in the upper hose. This setup must have a small (as in 1mm) hole in the thermostat to allow a little water to flow to actuate the thermostat. Most old-style thermostats include this hole, often with a little rattle pin in it to prevent clogging.

IMO, the best setup is the Canadian Tom Shiels thermostat spacer with a dedicated bypass line. Keeps things the way Subaru intended and compensates for the much larger cooling system volume of the bus conversion.

The bypass line connects to the small nipple while the heater flow is now far enough downstream of the thermostat that it does not affect the thermostat action.

One thing that various people have pointed out is the need to use a genuine Subaru thermostat. Aftermarket thermostats may not protrude into the bypass flow enough to work properly.

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 · 2 Oct 2008, 9:34 am

#672635

The thermostat on my V6 is on the inlet to the water pump too.

Well it was until I removed it to install the electric water pump.

Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 · 2 Oct 2008, 9:38 am

#672637

Hi Wes

How do you find the electric water pump? I have one sitting in my cupboard.

Steve

hansend23 Learner Dubber

2 posts · joined Mar 2009 · 24 Apr 2009, 5:53 pm

#708817

ricola wrote:Here you go:

Also here's a diagram I did for the Libra's conversion:

I'm guessing all this isn't such a problem for you guys but in cooler climates it is. A lot of the Canadian vanagon guys use a thermostat spacer, that brings it further away from the cold return and lets the bypass work a bit better.

New guy here! so i think i have it right.bypass to heat,mid to top engine out,and the one on the right to rad. im happy to find this.mine is a behr,made in italy.
looks to be the same function.

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 25 Apr 2009, 5:33 pm

#708943

funny trawling thro ebay last night looking at Beema radiators i came across one of those thermostat assemblies brand new

hansend23 Learner Dubber

2 posts · joined Mar 2009 · 26 Apr 2009, 6:26 am

#709006

mine isnt working.it fluctuates and doesnt get hot enough.
and when the stat is open the bypass closes so no heater flow.
why does it work on ricolas?and not mine😢
about 14litres of coolent?
exposed metal lines?
lines bolted aginst the pan?

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 26 Apr 2009, 8:18 am

#709012

i'd make a bet the extra long lenght of your lines as well as the heatercore being all the up front would be playing a part in it

that huge merc rad is plenty big enough and the rad feed line loses abit of heat along the way
how come your bypass is closing?

ricola Wolfsburg Wizard

437 posts · joined Feb 2003 · 27 Apr 2009, 3:05 am

#709198

I've been talking offline to him about it and I'm sure it is his heater return not plumbed in to the normal cool side properly. A mate has his sti speedster replica plumbed in like this and it works great, bleeds easily too..

http://www.ricola.co.uk

TheLionOfAfrica Learner Dubber

3 posts · joined May 2009 · 18 May 2009, 11:56 am

#713119

Hi everyone
I have a Toyota 3ct diesel in my syncro.
Its a great conversion, except I tend to have a problem with cooling when taking on steep inclines (like mountain pass's).
with 4x4'ing it's great, I can go anywhere with her.
some vid's on
http://www.bastilledeblignaut.co.za/4x4.htm
(at bottom of page)
can anyone help????