alan.gilbert_6384 Posted June 6, 2020 Report Share Posted June 6, 2020 Hi All, I have replaced the standard temperature heat gauge with a combined oil and heat as per picture. The original gauge needle only got to exactly the same place as you can see in the picture on the new gauge (the original being the electrical one and the new one being capillary). I assume that as both are reading the same they are both OK and correct (it would seem to be a bizarre coinsdence if both read wrong). I have checked and it seems to be fitted with the standard 82c thermostat, question is, should I change to an 88c thermostat to see if I can get the needle to mid position where it should be ? The 1500 has been fitted with a wide radiator so cools better, but I don't think that's why it won't get hotter as the stat controls release temp from the head to the rad. The engine runs fine, I just want to see what would happen if I can get the needle to the mid position, I presume it will better running at nominal temp rather than a tad lower as at present. Any thoughts ? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted June 6, 2020 Report Share Posted June 6, 2020 Isn't the 1/3 position where they're meant to be? Most of my gauges show about 1/3 along the range, and I'm happy with that - if it goes up to half I know something is amiss. 82 degrees is standard for summer and 88 for winter; you may find that running the hotter thermostat can cause problems on hot days, and we've had a few recently. If you're worried that yours isn't getting up to temperature then going by the gauge I'd say it's fine. (I'd be more concerned by the zero oil pressure... ) Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 6, 2020 Report Share Posted June 6, 2020 being a later /leaner car the 1500 is spec'd at a 88c stat not 82c (used on all the rest for std UK use) https://www.canleyclassics.com/?catalogue=triumph-spitfire-mkiv/1500&diagram=triumph-spitfire-mkiv/1500-water-pump-and-fan-european pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted June 6, 2020 Report Share Posted June 6, 2020 There's always one that doesn't conform.... but I'd still be happy with the gauge at 1/3 rather than 1/2. Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 6, 2020 Report Share Posted June 6, 2020 yes agreed ,, leaves room for some ....heat Pete Link to comment Share on other sites More sharing options...
dave.vitesse Posted June 7, 2020 Report Share Posted June 7, 2020 Most cooling system on classic cars don't stick to the a given figure or point as do most of the modern cars. The ambient, air, temperature has a great effect on the running temperature of the engine. The engine runs cooler on a cold day and hotter on a hot day. The 82C is the standard and 88C the winter stat. The point of using the 82C is it allows for this change or swing in ambient temperature. However, in the winter with the much lower ambient temperatures this becomes more difficult and the engine tends to run too cool. Hence the use of the 88C. Dave Link to comment Share on other sites More sharing options...
Colin Lindsay Posted June 7, 2020 Report Share Posted June 7, 2020 I always saw the thermostat as the average point in the middle of a range - when the engine is too hot it tries to keep it cool and when it's too cool it tries to keep it hot; the rad is just there to provide the means of cooling and of course the engine provides the heat. It has a limited range of temperatures that it can control hence the 88 for when it's cooler (or a 76 for when it's really hot). Technically you could have an entire range of in-betweens, but it's just two points that were chosen for more or less optimal running temperatures and they will fluctuate to an amount either side, which will be dependant on the outside ambience and the airflow. Link to comment Share on other sites More sharing options...
dougbgt6 Posted June 7, 2020 Report Share Posted June 7, 2020 These gauges really aren't very accurate, the important thing is, is it reading the same as yesterday? Has it changed? Is it hotter than before? We don't like change! My temperature gauge always sat dead in the middle until I did an extensive clean and backwash of the block, then it dropped half a division. Cleaning is good. Doug Link to comment Share on other sites More sharing options...
Gully Posted June 8, 2020 Report Share Posted June 8, 2020 I'm with Doug on this - with different radiators, thermostats and senders, not to mention 50 year old gauges, the readings are no more than an indication. I know where mine runs 'normally'. If it suddenly changes, I know something's amiss. For the record, mine runs just over the middle in winter, a little above that in summer and will happily sit at 3/4 in traffic in the summer. I had a faulty temperature sender a few years ago - the gauge has registered warmer since changing the sender, but same profile of reading. Gully Link to comment Share on other sites More sharing options...
Chris A Posted June 8, 2020 Report Share Posted June 8, 2020 Plus one more. I know where it sits and the slight movements to either side depending on conditions. If it were to go outside these then I would start to worry. Link to comment Share on other sites More sharing options...
alan.gilbert_6384 Posted June 8, 2020 Author Report Share Posted June 8, 2020 Cheers all, think I will lave as is then @colin, I too was very worried about the lack of oil pressure, did a few hours fault finding then realised the ignition was off when I took the picture 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted June 8, 2020 Report Share Posted June 8, 2020 Plus one more re the gauges. Dave Link to comment Share on other sites More sharing options...
Nick Jones Posted June 8, 2020 Report Share Posted June 8, 2020 The filled system mechanical gauges are pretty accurate. I have had a similar one for decades (probably ex MGB), though with actual degrees C marked. It's been tested in boiling water a couple of times and has always shown 100ºC at that point. Car doesn't actually boil over until just shy of 110ºC indicated, but doesn't usually get beyond 105ºC even climbing an Alp behind a caravan on a hot day. Typical UK running temperatures are 75 - 80ºC. It's an 82ºC 'stat. As for the 1/3rd reading on both gauges, I am mildly amazed that your filled system gauge reads the same as the old electric one did and suspect that they are both telling you that your thermostat is weary and opening too soon. Without and actual calibrated thermometer, about all you can do is try another thermostat. I'd probably stick with an 82. Nick Link to comment Share on other sites More sharing options...
Clive Posted June 9, 2020 Report Share Posted June 9, 2020 Following on from Nicks post, it may be worth checking teh capillary gauge in boiling water. Easy enough especially if you have a camping stove or a spare electric kettle handy! That would give you a good idea of the gauge calibration. And a new thermostat would be worth a try. Worth remembering running too cool is bad news for an engine, the oil really does not like it. Link to comment Share on other sites More sharing options...
Anglefire Posted June 9, 2020 Report Share Posted June 9, 2020 On 07/06/2020 at 13:38, dave.vitesse said: Most cooling system on classic cars don't stick to the a given figure or point as do most of the modern cars. The ambient, air, temperature has a great effect on the running temperature of the engine. The engine runs cooler on a cold day and hotter on a hot day. The 82C is the standard and 88C the winter stat. The point of using the 82C is it allows for this change or swing in ambient temperature. However, in the winter with the much lower ambient temperatures this becomes more difficult and the engine tends to run too cool. Hence the use of the 88C. Dave Most modern cars, the temperature gauge is controlled by the ECU and will read in the middle of the normal for a huge temperature range - my disco would be normal at a notional 90'C (From memory) - but would be in the same place from anything around 75/80 to 100 - it didn't get into the red and the warning light come on until it got to about 105 - normally in quick succession. I knew this because I had a diagnostic reader that would display the actual temperature. Link to comment Share on other sites More sharing options...
dave.vitesse Posted June 9, 2020 Report Share Posted June 9, 2020 8 minutes ago, Anglefire said: Most modern cars, the temperature gauge is controlled by the ECU and will read in the middle of the normal for a huge temperature range - my disco would be normal at a notional 90'C (From memory) - but would be in the same place from anything around 75/80 to 100 - it didn't get into the red and the warning light come on until it got to about 105 - normally in quick succession. I knew this because I had a diagnostic reader that would display the actual temperature. I agree it's how the ECU processes the info. We are getting new owners comparing their classic with a modern car. It's right they ask the questions are their could be something wrong. I was recently asked why the electrical system on 1950/60's cars was so basic and a poor design. My reply was, it wasn't if you compare it with cars of the 1920/30's, I think that goes for most of the car. Technology and social views march on with time. I am glad we get these questions because it make us think just how thing do work and what is normal in our classic cars. Dave 2 Link to comment Share on other sites More sharing options...
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