Water temperature

[Hurvinek]

Hi folks!

While browsing fotos of several Austin Sevens on the web I realized that most of the cars from 1932 onwards don't have a Boyce Motormeter on top of the radiator. But there is also no temperature gauge on the dashboard... 

Question: How do you deal with not having control about the water temperature? Just let it boil when it's starts to or what?

Sorry, I'm still learning...  Thank you in advance.

[Nick Lettington]

I have a 1936 four seat open road tourer with no provision for a gauge. I have never found the need for one. Perhaps ignorance is bliss? It hasn't ever boiled on me, but I live in Essex... one of the flattest counties on this island of ours.

[Howard Wright]

Hi Hurvinek

I don’t think any Seven was fitted with a temperature gauge (perhaps the Big Seven did?)

‘Boyce Motormeters’ were aftermarket accessories along with some other makes.  Replicas are available from the Cherished Suppliers.  However the originals and replicas are not very accurate.

I have a replica Motormeter on my RK and a small alcohol glass thermometer fitted into my radiator cap. I find it difficult to read either gauge and, in truth, they are there for show!

I don’t run with a fan belt unless the weather is very hot and have only had the water boil on one occasion when I was stuck in very slow moving traffic for over half an hour.

Unless the engine is badly clogged up I think the Seven is over cooled.

Cheers

Howard

[Colin Morgan]

So long as everything is in good condition, the thermosyphon sorts itself out - the higher the temperature, the greater the cooling flow. So a temperature gauge would perhaps be only of use to show a cooling system problem? The only time my car ever boiled was after a stud became loose at the bottom of the radiator, allowing the water to gradually escape. However, even this might not have been picked up by a sensor as it would have been in air, and not water.

The oil pressure gauge reading gives me an idea of how hot the engine is running. It falls away when the engine is working hard on warmer days - suggesting that I perhaps should back off a bit. (It is a late Ruby 3-bearing engine - so reads about 5psi when all is well at 30-40 mph. Pressure is less important with a two-bearing engine since there is no directly-fed centre-main to keep lubricated, but still might give an idea if the engine is getting particularly hot.)

[Ivor Hawkins]

Water temperature gauges on Austin Sevens are for Promenade Percies!

Never, ever needed one, even in a special.

[Reckless Rat]

There is a lot of coolant in an A7 thermosyphon system and providing all is well with it you really shouldn't have to worry about overheating. My RP has been up and over the Alps & the Pyrenees several times and never once got to boiling point. As stated by Colin, the oil pressure gauge on a splash fed engine will give you a good idea if things are getting hot, but this usually only occurs when the engine is working hard in a lower gear. If things are getting really hot under the bonnet it's possible that some vapour lock may occur, (with loss of power or misfiring) but if that's the case just run with the bonnet open until it cools down. Once over the top of a climb things very quickly return to normal.

My advice is forget the temperature gauge, it's just something else to worry about. More important is ensuring that the engine warms up quickly.

[Hurvinek]

Thank you to everyone who replied. 

Well, I've never driven a car without a temperature gauge yet, and there are steep mountains here and it's hot in the summer too. Unlike the British Isles. But what you all say makes sense, actually you don't need it when the car has no water pump. I'll get used to it and at some point I won't even think about the temperature anymore.

And...
"(...) in truth, they are there for show!"

And...
"Water temperature gauges on Austin Sevens are for Promenade Percies!"

I don't want that, so get rid of it. So, does anyone need two used Boyce Motormeters? I would give both away for little money...

[Steve kay]

I have a temp gauge on the Ruby, definitely not essential but sometimes interesting. Certainly agree with above comments about cooling being perfectly satisfactory. A good radiator core and cleaned out block keep boiling far away. Sevens who joined us on the Cotswolds Tour during the Centenary Week may have has occasional challenges but in general boiling was unusual, although for certain Chummies, bonnet removal up on short but very steep hills was one response. Watching the temperature indicates what a small volume of coolant as the temperature changes rather frequently and quickly. So keep those passages clean and don’t worry!

[Tony Griffiths]

Everybody agrees that a Seven in decent condition is overcooled and so a temperature gauge is unnecessary. Unlike later cars with their sealed, pressurised systems, that on a Seven is "open" and there will be a little water loss due to evaporation and, if it does boil, down the radiator overflow pipe. Hence, a check on the water lever is, now and again, necessary.

[Barry Townsend]

I've gone a different route and fitted a thermostat to my RN. As you would expect the warm up period is much reduced and the temperature stays pretty constant, winter and summer. The Boyce meter seems to be fairly accurate in keeping with the conditions.

I live in North Wales and encounter all sorts of roads.

The purists would argue that it is not needed but I would counter argue that the bulk of engine wear takes place in the first few minutes of running a cold engine. Each to their own.