MKV (5) 3.5 litre Coolant Gallery (Water Rail)

Dear All
Help please - rebuilding a MKV engine I’m looking for a 3.5 litre engine coolant gallery (water rail) as ours has serious corrosion leaks.
Any advice or assistance is very much appreciated.
This request now added to Classified wanted ads.
Thank you and Best Regards

Hi David, this should really be in the Classifieds Wanted section.

Hi Robin - thank you for letting me know.
I wasn’t sure where to put this item as I was really looking to see if anyone could suggest a welding or some other process for repair of the original item, if that fails where indeed to find a replacement.

Welding aluminum is certainly possible by the MIG or TIG methods. I have done some MIG.
A picture or two would help us with making suggestions.

You don’t need to weld it. With HTS2000 you can braze it with an ordinary propane torch. It puddles nicely and the bond to the original alloy is stronger than the alloy.

The example below had the large hole filled using a paddle pushed up inside just to retain the puddle. It also had a new thermostat fixing lug created with HTS2000.



Dear Rob and Peter
Thank you for your replies.
I’m really impressed with the HTS2000 that may be the way to go.
Please see the attached photo’s as requested, not a pretty sight.
Best Regards

It looks like there are some old repairs on there already.
The HTS2000 looks like worth trying, especially as less heat will mean less warping than MIG.
Either way, you will want to clean it up and grind away any badly corroded material, to expose new clean metal for the repair to stick to.

Hello David, looks like that water uptake manifold has seen some repairs previously. While it looks bad, the photos may indicate leaks due to poor gasket sealing rather than leaks at the metal. This can be due to the corroded material giving a pretty uneven sealant rim. It looks in the photos like your three head ports have flat metal surfaces and may seal okay if cleaned and done carefully. I point this out since it might be a good idea to get a second water uptake manifold before attempting any further repairs on the existing one. An irritating but working existing one is better than a non-working repaired with-an-oops moment. The manifolds do come up for sale here and there.

Dear Rob and Roger.
Thank you for your replies, very much appreciated,
As you observe, the manifold has had extensive work done by a previous owner.
I have ordered a few sticks of the HTS2000, I will take the advice and clean up the joint faces before anything else and then very low pressure test (1 to 2 psi). If successful, fine, if not I will try the HTS 2000 and try to obtain a replacement in the meantime.
I will report back on the outcome.
Thank you again

SNG Barretts make a new Water Rail which just needs finishing.

Part No. C520

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I bought one of these a few years ago to overcome the same litany of corrosion and bad repair and a crack at the heater spigot connection. Beautifully made casting and pricey of course.

The major work required is to drill all holes. The intricate ones are the half dozen to match the head studs. Not having any sophisticated workshop equipment, I proceeded with care, bringing the holes up to size and centricity over four or five drill sizes. After each size a check was done for verticality, centricity and alignment and a realignment done with the next drill size. I fully expected to have to do some final fitting by dressing a hole or two slightly with a round file. To my surprise, it slipped over the studs like a smooth glove. Sometimes there are occasions when you can sit back with your afternoon coffee with a smug smile on your face. No one else understands why you are so pleased.

The other work required was to face the flanges. I used a large flat file, checking with a heavy section straight edge and got it to a point where a feeler gauge would not fit.

The other decision to make is the finish required and I will probably get my electro-plater to buff it.

Was it worth the cost and work? Definitely yes, as this is a high visibility feature of the engine that must be left in natural colour and texture. It ranks equally with the rocker cover and carburettors for presentation. Though my original can be repaired - and I may give it a try with that low temperature stick - the repairs will be hard to disguise.


Dear Tim and Peter.
Thank you for your posts.
I will certainly consider one of these SNG Barratt castings (and good to know that these are available), if the HTS2000 or other 2nd hand manifold are not successful.
Thank you again.

Rare but lovely moments, Peter. :innocent: