Coolant catch tank

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simonjrwinter
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Re: Coolant catch tank

Post by simonjrwinter » Wed Aug 07, 2019 2:19 pm

This was an education for me, I’ve been driving for almost 45 years, but this basic principal of the cooling system (the return bypass) has completely passed me by,
I’ve now ordered an overflow/expansion bottle for my car!
Simon
TR6 (V8) Hawk 289 FIA (V8) Doing my bit for global warming.

peterc
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Re: Coolant catch tank

Post by peterc » Wed Aug 07, 2019 6:29 pm

Stuart,
I will attempt to get my camera in but not sure how well the photo will turn out.
Basically you will need to make a cardboard template which will end up D shaped with tabs on to bolt onto the rad support brackets.
The old principle of marking a straight line across the width with marks every 10 mm. Then measure out at each point horizontally to touch the nose portion of the car will give you the necessary shape of the D. It will be sort of elliptical.
At the rad end of the baffle you will require a short section folded down to align with the core of the rad.
I’ll see if I still have my template to take some dimensions.
More anon.
Peter C

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Re: Coolant catch tank

Post by Jerryedmans » Thu Aug 08, 2019 12:43 am

Many thanks for all the useful advice from all parties. I've not overheated yet (got the mother of all radiators!) but hopefully the overflow catch tank will bring the level up a bit higher in the expansion tank which appears too low at present. Cheers. J

peterc
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Re: Coolant catch tank

Post by peterc » Thu Aug 08, 2019 12:55 pm

Stuart,
Photo as requested.
rad top duct R.jpg
I realise now that due to the position of my fans I couldn't get the baffle low enough to have a straight approach into the rad core. The 10 mm lip was needed to finish off the duct but the plus point being that it stiffened it up across its width.
I can't find the cardboard template so assume that I have chucked it out so you will have to conjure up the dims by measuring yourself.
Hope that assists.
Peter C

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Migge
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Re: Coolant catch tank

Post by Migge » Thu Aug 08, 2019 3:10 pm

PICT6816.JPG
Keep the air through the radiator
PICT6820.JPG
PICT6890.JPG
PICT6891.JPG
Special customized BRA289

simonjrwinter
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Re: Coolant catch tank

Post by simonjrwinter » Thu Aug 08, 2019 4:38 pm

Fitted my catch tank today. Have run a bead of epoxy around the vent in the header tank. If that doesn’t seal it I guess I’ll need to find an aluminium welder....
Simon
TR6 (V8) Hawk 289 FIA (V8) Doing my bit for global warming.

peterc
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Re: Coolant catch tank

Post by peterc » Thu Aug 08, 2019 6:18 pm

Simon if you go for the non pressurised catch tank it will probably be OK.
Keep the pressure cap on the rad and have the catch tank at atmospheric. I confess I didn’t know the central cap had a vacuum relief to allow the water back in.
Peter C
As for Migge’s ducting photos I wouldn’t have expected anything less from a master in Ali fabrication.
Puts my attempts to shame.

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Re: Coolant catch tank

Post by stu60 » Fri Aug 09, 2019 6:51 pm

Wow.... thanks Peter, i might be able to manage that mod but I think Migge's is somewhat beyond my metal bashing capabilities. Out of interest what pressure rad cap do you all use?

i have seen 10psi, 13psi and 15 psi.
thanks stuart

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clive
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Re: Coolant catch tank

Post by clive » Sat Aug 10, 2019 12:58 am

I am confused about this catch tank scenario. From what I can make out a catch tank is fitted to collect coolant that escapes when it expands, and is then sucked back into the system when it cools thus preventing coolant loss onto the road. The expansion tank that we have on our cars works on a similar principle in that the level in the tank should never be full when the engine is cold but level with the inlet/outlet hoses so when the coolant expands it fills the void in the tank and when it cools the level drops. (The level is easily checked when cold by dipping a piece of rolled up tissue in and checking the level against the outside of the tank.)

Fitting a catch tank along with the expansion tank seems to be pointless if the expansion tank is doing it's job properly. If you do fit a catchment tank then the cap on the expansion tank needs to be just a cap without the sprung pressure relief valve whilst the cap on the catchment tank will need to have a pressure relief cap.

As I have said in my previous post, I have used the expansion tank method for over thirteen years and 40,000 miles and I have never needed to top up the coolant in my car.
Cheers, Clive.

(If I'm not here I'm in my workshop or on the golf course!)

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Re: Coolant catch tank

Post by KevinW » Sat Aug 10, 2019 9:55 am

I can't speak for others but the standard Ford expansion tank on an FE engine has relatively little room for coolant expansion, so, on the recommendation of others i fitted a catch tank when i had overheating problems (now cured with a better cap, touch wood). The catch tank should be at atmospheric, only being used when the pressurised cap lifts, which then sucks fluid back when the engine cools - see vid above. Well that's the theory. But I agree, a well designed system used in normal operating conditions shouldn't need one.

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