AntonUK
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| posted on 31/1/16 at 09:30 PM |
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Raceline Water Rail and Expansion Tanks
In my 1.8 silvertop I have the raceline water rail fitted. Love em or hate them it was standard fit on my car so I'll be going ahead with using
it.
I purchased one of these as its expansion tank.
Polished All Aluminum Radiator Coolant Overflow Recovery Bottle Tank Universal
The rails overflow (the small pipe used when the pressure cap in the water rail activates) is plumbed to the bottom port of the tank and the top port
of the tank is blanked off. The expansion tank cap is a no pressure relief type and us essentially just a screw top.
Is this correct / safe to use?
My possible incorrect thinking is.. if/when the pressure cap in the rail activates and fills the expansion tank, if the pressure kept increasing
there is nowhere for the excess pressure to go and would result in a popped hose or gasket? Right/Wrong?
Build Photos Here
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arrow-engineering
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| posted on 31/1/16 at 09:50 PM |
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the cap on the expansion tank takes care of the pressure. with a raceline rail you need a small barbed union (same size as the small pipe on the
expansion tank) you run a hose from the barb to the top of the tank, this will be mostly air, together with the air in the tank. the feed from the
expansion tank should enter the cooling system low down on the water pump to rad hose.
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AntonUK
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| posted on 31/1/16 at 10:26 PM |
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Isn't that the setup for a header tank not an expansion tank?
Build Photos Here
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cliftyhanger
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| posted on 1/2/16 at 07:44 AM |
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In your setup the expansion bottle should vent to atmosphere.
And as long as the rad cap on the water rail is working correctly, as the engine cools the coolant should be sucked back.
However, with the water rail I found it worked best by using a header tank and changing the rad cap for a seal cap (or a rad cap with the gubbins cut
out) along with a couple of 3mm holes in the thermostat. Temperature was very stable with that, and none of the reported "issues" people
regularly post about. I believe that is because it allows water flow right up to the thermostat rather than leaving the water rail full of static or
slow moving water.
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jeffw
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| posted on 1/2/16 at 11:08 AM |
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quote:
Originally posted by AntonUK
In my 1.8 silvertop I have the raceline water rail fitted. Love em or hate them it was standard fit on my car so I'll be going ahead with using
it.
I purchased one of these as its expansion tank.
Polished All Aluminum Radiator Coolant Overflow Recovery Bottle Tank Universal
The rails overflow (the small pipe used when the pressure cap in the water rail activates) is plumbed to the bottom port of the tank and the top port
of the tank is blanked off. The expansion tank cap is a no pressure relief type and us essentially just a screw top.
Is this correct / safe to use?
My possible incorrect thinking is.. if/when the pressure cap in the rail activates and fills the expansion tank, if the pressure kept increasing
there is nowhere for the excess pressure to go and would result in a popped hose or gasket? Right/Wrong?
I have a plastic expansion tank with a clip type lid. In normal operation (once the rail has found its water level) the tank is never warm so I doubt
you will see any issues with your setup.
Raceline suggest just having a waste pipe down under the engine for any water overflow but I erred on the side of safety and pretty much did what you
are suggesting.
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AntonUK
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| posted on 2/2/16 at 07:38 AM |
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quote:
I have a plastic expansion tank with a clip type lid. In normal operation (once the rail has found its water level) the tank is never warm so I doubt
you will see any issues with your setup.
Raceline suggest just having a waste pipe down under the engine for any water overflow but I erred on the side of safety and pretty much did what you
are suggesting.
That's good to know. Does that clip lid have a small hole in it?
Build Photos Here
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jeffw
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| posted on 2/2/16 at 09:28 AM |
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No. it it just a plastic push fit lid. A vent in your screw lid might be a good idea.
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AntonUK
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| posted on 2/2/16 at 07:21 PM |
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quote:
Originally posted by jeffw
No. it it just a plastic push fit lid. A vent in your screw lid might be a good idea.
Cheers a perfect excuse to try out the drilling ability of my new mill 
Build Photos Here
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