Cooling systems

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Charlescrown
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Re: Cooling systems

Post by Charlescrown »

Oh and by the way gents we have all gone off on a tangent and overtaken this thread. Best get back to the thermostat location. Bottom hose is best by far in my books.
OZ38
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Re: Cooling systems

Post by OZ38 »

Charlescrown wrote:Oh and by the way gents we have all gone off on a tangent and overtaken this thread. Best get back to the thermostat location. Bottom hose is best by far in my books.
Well before you do.
In regard to the cast impellor vs the steel impellor.
The Holden part number for the water pump on the earlier V6's would see you get a cast impellor, where as the part number for the latter V6 (Ecotec) would see you receive a steel impellor.
A friend advised me to always ask for the VN/VP/VR V6 water pump when buying from Holden if I wanted the cast impellor.
MAGP
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Re: Cooling systems

Post by MAGP »

Charlescrown wrote:Oh and by the way gents we have all gone off on a tangent and overtaken this thread. Best get back to the thermostat location. Bottom hose is best by far in my books.
I thought I saw Immortality mention the Bennet cooling system which also encompassed the water pump and a bypass to redirect water flow and remove air bubbles.
Charlescrown
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Re: Cooling systems

Post by Charlescrown »

I don't know about the bypass setup. I do know you can't run without the thermostat on cars (not sure if it's all) with it located in the lower hose because they use 2 stage thermostats which also control the bypass flow so there might be a bit more to it than just fitting a unit in the lower hose.
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Gareth
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Re: Cooling systems

Post by Gareth »

What about fitting an ECU controlled thermostat from a late model euro car?.. :think:
According to chemistry, alcohol is a solution...
MAGP
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Re: Cooling systems

Post by MAGP »

I thought the bypass was before the thermostat so any air bubbles could rise to the top and find their way into the overflow bottle when the radiator cap vented pressure. Otherwise you'd get air caught in the lower thermostat housing because they don't sit vertically.
immortality
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Re: Cooling systems

Post by immortality »

As far as I can tell the original Bennett system incorporated something in the top hose fitting to remove any air bubbles, from what I've been told the newer versions have this in the lower hose fitting with the thermostat.

My thinking however is to slightly modify the system, have a simple fitting in lower hose with thermostat and bypass hose coming from the top (as per the original Bennett system but without the fancy separator system which I can't find any info on), then modify the rest of the coolant system much like the original VN V6 system with an expansion tank and a couple of small bleed lines from the engine which will bleed out any air. Air always rises to the top so the best place to remove it from the coolant would (in my opinion) be at the highest possible point on the engine or as close to it as is practical.

Another way to do it would be with a swirl pot fitted in the top radiator hose and the bypass been taken from that, then you wouldn't need to worry so much about fitting an external expansion tank and bleed lines etc.

edit: From what I've discovered, the Bennett system has evolved over the years, the original system is no longer available and the new lower hose fitting is now custom made to suit the application. The original system consisted of the upper and lower radiator hose fittings as well as a new water pump which my understanding is a OEM type pump that is then modified (I think a new impeller) as well setting up proper clearances and smoothing. I'm told one of these pumps costs ~AU$400+
MAGP
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Re: Cooling systems

Post by MAGP »

On the radiator side of the system I would think a simple bleed hose, like you have fitted to the back of your manifold, from the radiator side of the thermostat housing that exits near the radiator cap or at least in the tank the radiator cap is on would be sufficient to remove any trapped air in the radiator side of the modified system.
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vlad01
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Re: Cooling systems

Post by vlad01 »

MAGP wrote:I thought the bypass was before the thermostat so any air bubbles could rise to the top and find their way into the overflow bottle when the radiator cap vented pressure. Otherwise you'd get air caught in the lower thermostat housing because they don't sit vertically.
The bypass is for "temp sensing" for the stat, otherwise it would never open. I helped out a lot of people with this problem doing EJ25 conversions in vw bugs. Problem was everyone was blocking the bypass off as it was also part of the heater loop, most vw don't want heaters so they block it off and the engine overheats in 5 min.

typical vw people have no clue how a cooling system works lol :lol:
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
MAGP
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Re: Cooling systems

Post by MAGP »

Do you have any pics of the setups you have worked on Vlad?
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