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MG MGA - Water Wetter

Partly related with the thread on rusty cooling water I have received my bottle of water wetter and members may be interested in the claims on the bottle for lowering coolant temperatures that I do not dispute but include here as a matter of interest. They are listed as 'Dyno Test Results' that I take to mean the results came from one or more tests from an engine under load.
50/50 glycol water 228 degrees F
50/50 +water wetter 220
water only 220
water + water wetter 202

From the above there is the prospect of an 8 degree drop with water wetter but the improvement with no glycol added is 26 degrees! If only there was a rust inhibitor and anti freeze that was not detrimental to heat transfer. Down south in the UK we hardly have a need for antifreeze and its tempting to speculate whether the improvement in cooling might allow an engine to run just with water wetter and a 7 psi cap and live with a lower boiling point. I know that antifreeze has a few other properties but in localities where it never even gets cold I wonder if its used there?
J H Cole

Assuming water wetter is just a detergent to lower the surface tension, let me say that surface tension plays no part in liquid phase heat transfer where there is no liquid / gas interface. The cooling rate depends on heat transfer from the air to the tubes, through the tubes and from the water to the tubes. Through the tubes resistance is the least of these. In the water, the resistance is due to the fluid properties - viscosity and thermal conductivity only and the water flow rate. Low viscosity, high conductivity and high flow are good. Additives in small amounts do not change either the viscosity or conductivity, so cannot help. Water has less viscosity and higher conductivity than glycol. Usually, air side resistance is by far the highest, that's why the tubes are finned, to increase the area. All this is basic heat transfer technology, well documented. Save your money on WW I'd say.
A Pearse

Thanks AP and I think your saying that ww is not effective but don't, as politicians say, the results speak for themselves (as shown above assuming they're accepted)?
J H Cole

AP, forgot to add that an explanation for WW working is that it inhibits the formation of vapour bubbles on the metal surface when close to boiling and hence helps retain the full surface area contact as a water/metal interface longer than otherwise would be the case. I know I'm putting my head on the block here but it sounded believable.
J H Cole

I've tried all the radiator fluid mixes above including the WW to help cool my 1500 engine but nothing did until I installed the blanking sleave.It made the differance and the temp. dropped to around 190. I'am also convinced now that adding the extra cores was wrong and I'm hopping someone out there has a spare MGA rediator that they would sell me? My car is a 1956 MGA Tom
Tom Peotter

Tom makes a very good point, why do you need to improve cooling? The answer is always that your basic system has a fault. The MGA cooling system when in good condition is more than capable of doing its job without other gimmicks. That especially so in the UK where temperatures never reach the excesses experienced in warmer parts of the world.
Bob (robert) Midget Turbo

We use water wetter in our cars. It seems to give us 10 degree cooler running temp, but with all the different cooling set ups MGA's have(oil coolers electric fans, different raidiator cores)it is hard to compare. All I can say is it works for me.Bob
B WALKER

I can't remember where I've read this but I think that it was from a published article that accepted that the MGA radiator (as originally set up) when working under full load was marginal for cooling. I know that there are lots of owners that seem to be able to keep the temperature below say 190F but for motorway driving on a hot day especially with an incline I think most standard cars will start to have problems. UK motorways weren't around in 1956.
J H Cole

I am with Bob on this one. I believe many owners spend too much time, energy and money treating the effect rather than cause.

The original MGA radiator design appears to have the optimum layout that includes the number of rows, pipe diameter, pipe spacing and fin spacing.

Probably a majority of MGAs on the road today have rebuilt radiators. If the rebuild is not to the same configuration as the original it would be my starting point for getting to the root cause of an overheating problem.

JH, If anything, I actually find my car runs a tadge cooler once I get it up to speed on the motorways. I have always assumed it to be the extra air being forced through the rad offsets the extra engine heat being generated.

Steve
Steve Gyles

I've had bad experiences with Water Wetter. First used it in a V12 E-Type after I changed all the hoses, and it leaked out of lots of places, so I drained it and binned it - and leaks stopped. When I got the A two+ years ago, coolant was leaking out of the water pump. Contacted the PO who told me it started when he put in WW (and the same thing happened to his MGB). I fitted a new pump and binned the WW, and evertything is now fine - temp is normal at usual running speed no matter what the weather, and rises a small amount on motorway journeys. Wouldn't touch the stuff again under any circumstances. If the car started overheating, I would look for and cure the root cause. AB
A Bennett

This thread was discussed between 21/08/2008 and 28/08/2008

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