engine cooling

[murcod]

What is used in place of water?

[James]

I'm not sure — presume it's oil based?

It has a much higher boiling point and doesn't expand — so you don't lose it if you overheat.

I believe it stops localised hot spots too.

[Alec]

Hello James,

it is a significant loss if a hose ruptures or a stone goes through the radiator?

Alec

[James]

Alec,

It would be expensive that's for sure— you can top it up with water but you lose the advantages.

You'd want all your hoses in good condition.

James

[sprint95m]

I've been considering waterless coolant — looks like it'll cost at least £100 to do the conversion though.

Nearer £150 ,
because you need to buy Prep Fluid if you are converting an existing system.


I am running a Triumph Dolomite on Evans Waterless Coolant.
It is quite amazing stuff, it has 180 degree boiling point, avoids caviation (localised boiling) and hotspots, runs at very low pressure, etc.
With regard to the last point, you can remove the expansion bottle cap/radiator cap whilst the coolant is hot and it doesn't react.
It places less strain on all the various components, hoses, pipes, seals etc.
Crucially it does not corrode the engine, so no need to drain/flush every two years.


Conversion is easy to carry out.
You simply drain the system, refill with Prep Fluid and run up to temperature.
Leave to cool, drain and refill with Evans coolant.
It is a longterm investment but it is perfectly feasible to make a financial saving.


It may be possible, on a Triumph six, to advance the ignition timing without inducing pinking and also you can probably run
with an 88 degree thermostat instead of the normal 82 degree version? These offering potential fuel economy benefits?

[Alec]

Hello Ian,

I'm not convinced by the blurb on their website. E.g., localised boiling, if that occurs then that would be beneficial as the heat required to boil water is several hundred times that required to raise it by one degree, i.e. it will remove a lot of heat. Marconi used that principal to cool their long range radar Magnetrons. Reduced corrosion could be a benefit if you have a very rare engine but Triumphs don't seem to suffer too much?

Why would you want to run increased advance, that could be a course for engine damage?

Alec

[David Withers]

<snip>... it has 180 degree boiling point, avoids caviation (localised boiling) and hotspots, runs at very low pressure, etc.
With regard to the last point, you can remove the expansion bottle cap/radiator cap whilst the coolant is hot and it doesn't react. <snip>
Crucially it does not corrode the engine, so no need to drain/flush every two years.

Sorry, I have to disagree on two points:

1. Cavitation is not "localised boiling". It is the implosion of gas bubbles that have been formed by high pressure and then immediately subjected to low pressure, causing metal in the immediate vicinity to be eaten away. I doubt if our Triumph engines ever experience it. The engines that can sometimes suffer from it are wet-linered diesel engines where the liner vibrates due to cylinder pressure pulsing and the resulting cavitation eats away at the liner/block interface. Some Rolls Royce diesel truck/railway engines and Peugeot car engines used to suffer from cavitation if the coolant additive wasn't sufficiently effective. It can also occur in water pumps and eat into the impeller, but again almost certainly not in our Triumph engines.

2. Surely draining and flushing the coolant every two years isn't necessary so as to avoid corrosion on the Triumph engines. Draining and refilling, with antifreeze added, is needed only when the existing antifreeze has lost its protection against freezing - which may or may not be as soon as two years. I'd say that even an old and weak mixture will protect our engines from any damaging level of corrosion; I've always left mine for much longer than two years as I prefer not to refill with fresh water more often than necessary.

Is the Triumph cooling system really so poor that it needs a £150 'upgrade' to make it do the job it was designed for? Do premium car makers such as RR, Bentley, Mercedes, BMW, etc fill the systems on their new cars with waterless coolant? They would surely be strong candidates for it if it was truly worthwhile, especially on high-output aluminium engines.

[sprint95m]

It is a Dolomite 1850 that I have.
Triumph slant four engines were fitted with no fewer than three different versions of water pump impellor. Cavitation is a well known
problem with these. A fourth alternative was made by Saab.
The problem is somewhat reduced by using an expansion tank with an output connected to the bottom radiator hose.
I have employed a Volvo 850 tank. This also features a low level warning (which will activate before the level drops in the engine)
which is a very sensible fitment.

Dolomite 1850s are very prone to coolant loss from the front of the inlet manifold. I have fitted helicoil inserts and made up my
own gaskets (the repro versions are very variable for accuracy). This coolant loss is less likely with Evans coolant because the cooling
system is not so pressurised.

I have fitted silicone hoses because you can no longer buy fabric reinforced rubber and replacing kevlar hoses every year is not
for me. It may well be the case that the kevlar hoses would last longer in conjunction to Evans coolant?

The hottest part of a Triumph slant four is towards the back of the head. I have contacted someone who will be able to measure
the temperatures throughout an engine to compare water/antifreeze mix to Evans waterless but he is some way from having a
running Sprint. On overheating, slant fours are prone to blow the head gasket between 3 & 4.
Sprintparts (Sydney, Australia) run their race cars on Evans coolant. On cooking a race engine recently it was okay to use it again because
it hadn't blown the head gasket (which it would have done normally).

It is a bad idea to leave water based coolant in a Dolomite for more than two years because the radiator will readily clog.
In my experience, 2000s are less prone to this sludging but I have still have had to remove radiators to flush them out.



Evans have been around for about a decade. Their primary market seems to be the North American HGV sector but their other
big market is for use in various types of racing engines.
They now have a factory in Swansea and this European operation is also targeting the classic/vintage car sector.

There was a similar negative reaction to Evans Coolant on the Dolomite Club forum. One contributor seems to think that his
approach of adding nearly 1/2 litre of water and antifreeze every 100 miles is a better option (a Dolomite only holds 5.4 litres).
The main objection raised was the cost. The folk who were interested are all like me, their Dolomite is their only transport (although
I have a bicycle too ).



Thanks,

[David Withers]

That's a well-presented and interesting account of the corrosion problems on the Dolomite slant-four engines, and I hope you've found the cure. However I stand by my "negative reaction" as this forum relates to cast iron engines that don't suffer those problems.

[sprint95m]

The cast iron engines, 4 and 6 cylinder do suffer cooling system problems too.
The common ones relate to the steel pipes that run both behind and through the inlet manifold. These can corrode internally.
I have used stainless steel pipework from Chris Witor to try and avoid this problem.

None of the 2000 range has a coolant low level warning.
A header tank with a low level warning is worthwhile, especially if said tank can be positioned so warning comes on before the
coolant level drops in the engine. On a 2000 employing one of these will possibly involve using a different radiator and/or modified
thermostat cover?
I was lucky one time when I had a burst radiator on a 2500S. A large pool of coolant had appeared under the front of the car whilst
parked in a public car park. I was able to go to the nearby toilets to obtain water. It took nearly 1.5 litres.
Keeping an eye on the temp gauge, I drove the 18 miles home. The coolant was escaping through a pinhole in the radiator.
Worryingly (?) the temp gauge didn't show any increase despite the coolant loss*.
I fitted some fine alloy mesh to try and prevent any future stone damage reoccurance and started to carry some coolant, just in case.

Once I saw what looked like a very clean H reg white 2000 in an Edinburgh scrapyard. It had a nice interior too.
However it had clearly been cooked because the engine bay and bonnet underside were coolant stained. Seemed a shame to
scrap it when engines were plentiful (if that was indeed the reason for its demise). I think it was a top radiator hose that had failed.
That yard had 3 or 4 other 2000s.




*Dolomite 1850 and Sprints also do this. There is a warning in the workshop manual about it. Since the coolant is routed to the
heater via the inlet manifold it is possible to confirm coolant loss because the heater stops working !
HA Vivas were like that too .