Cold Weather Running
Discussion
As the cold weather starts thought I would post my experience over the last week.
I normally put a blanking shroud in front of the rad which covers around 250mm of the rad, but because it has not been very cold did not do this at the end of summer.
Decided to have a run out during the holidays, and after coffee stop the car would not hold a steady idle, eventually stalling. When I got home pulled the plugs and found them black and very sooty - deduced the car was running too cold while on the move and running enrichment as if cold.
So decided to put in my blanking shroud, as on holiday decided to see how big this could be without overheating while not moving - it now blanks off around 3/4 of the rad leaving just 2 small parts exposed at each side.
Well - it has transformed the car - not only running in the sweet spot and very sharp, but the heater is now actually being felt putting some warmth into the cabin. At idle the temp reaches 90 deg and the fans come on and off to hold this temp, on the move temp drops to around 80. Think the mpg figure has improved as a bonus.
Would like to get the on the move temp to be 90, but think it would over heat standing still - perhaps an active shroud would be the answer but do not want to complicate things.
Am going to modify the shroud as so much of the rad and fans are covered and concerned about overloading or overheating the fan motors. Think I will bracket the shroud off the rad face by around 50mm. This should stop the cold blast while moving but allow the fans to get some air in from around the sides.
Andy
I normally put a blanking shroud in front of the rad which covers around 250mm of the rad, but because it has not been very cold did not do this at the end of summer.
Decided to have a run out during the holidays, and after coffee stop the car would not hold a steady idle, eventually stalling. When I got home pulled the plugs and found them black and very sooty - deduced the car was running too cold while on the move and running enrichment as if cold.
So decided to put in my blanking shroud, as on holiday decided to see how big this could be without overheating while not moving - it now blanks off around 3/4 of the rad leaving just 2 small parts exposed at each side.
Well - it has transformed the car - not only running in the sweet spot and very sharp, but the heater is now actually being felt putting some warmth into the cabin. At idle the temp reaches 90 deg and the fans come on and off to hold this temp, on the move temp drops to around 80. Think the mpg figure has improved as a bonus.
Would like to get the on the move temp to be 90, but think it would over heat standing still - perhaps an active shroud would be the answer but do not want to complicate things.
Am going to modify the shroud as so much of the rad and fans are covered and concerned about overloading or overheating the fan motors. Think I will bracket the shroud off the rad face by around 50mm. This should stop the cold blast while moving but allow the fans to get some air in from around the sides.
Andy
What value thermostat are you using? My car was fitted with a 74° stat and rarely exceeded 70° unless caught in traffic. Changing to the correct 82° cured the problem and now temps. are between 82° and 92°, when the fans cut in. I have read that the Land Rover block was originally fitted with an 88° stat. but that may be a step too far.
Edited by Hedgehopper on Monday 31st December 19:53
Edited by Hedgehopper on Tuesday 1st January 11:32
What value thermostat are you using? My car was fitted with a 74° stat and rarely exceeded 70° unless caught in traffic. Changing to the correct 82° cured the problem and now temps. are between 82° and 92°, when the fans cut in. I have read that the Land Rover block was originally fitted with an 88° stat. but that may be a step too far.
Edited by Hedgehopper on Monday 31st December 19:53
Edited by Hedgehopper on Tuesday 1st January 11:33
Belle427 said:
Maybe worth testing your current stat just to check it’s not stuck open or even if you have one fitted at all.
Beat me to it.Sounds like this will be the problem. If it was really freezing out then the stat would rarely open but heater temp would be fine. This reduced flow is the only reason you would shroud a rad to prevent it freezing not to control the engine temp.
Steve
I've run an 88° thermostat for years with great results and at no risk whatsoever, I do so because it's the stat value the engine was designed to work with. People still seem to misunderstand how a thermostat works and its function in the cooling system, so you often see low value stats fitted to TVR's in the hope they may somehow magically help with overheating issues.
To be 100% clear, if your car overheats you have an issue with your cooling system that needs investigating and correcting, fitting a lower value thermostat is not going to help because the function of the stat is merely to help the engine warm up and reach it's optimal coolant temp faster.
A 77° thermostat is fully open around 80°, engines don't overheat at 80° any more than they overheat at 93° when my 88° thermostat is fully open, in both examples neither engine even comes close to overheating which on a pressure sealed system can only occur above 105° and in reality more likely closer to 110°.
The capacity of the coolant system, the surface area of the radiator and the airflow through it is what governs the running coolant temp not the thermostat, at idle the car is stationary so the missing airflow generated by the car moving forward is replaced by the radiator fans. Given this and the fact the capacity of the coolant system and surface area of the rad in an engine fitted with a 77° thermostat is exactly the same as the engine fitted with 88° thermostat, neither stat will make a jot of difference to the engine's propensity to overheat or ability to control over heating.
However it should be noted the Rover V8 being an aluminum block engine is very good a dissipating heat all by itself, this is especially true when the engine is subject to high levels of cooling airflow rushing over it in the winter months when the car is driven at speed.
If you fit a 77° thermostat it will open way too soon so the radiator will come into play way too early, this will be especially noticeable in the winter months as the air cooled ally block effect will compound the issue. During the winter you want the coolant to remain trapped in the block and heater as long as possible before the stat starts to open to bring the radiator into the equation, a stat that opens too soon will just mean coolant temps will never get to the correct running target of 90°.
To be honest in the winter the engine may well never get up to full operating temp even with an 88° thermostat fitted due to the cooling effect of all that icy wind blast over the block. As I say I have run an 88° thermostat for years, without a rad blind fitted the engine will still struggle to get above 80° during a fast motorway run.
Without a rad blind in the winter months the over cooling issue can be directly linked to how soon after starting the cold engine I reach those higher speed cruising speeds. If I join the motorway too soon after a cold start my coolant temp will take ages just to eventually hit 80°, however it I join the motorway with a fully warmed engine the coolant will never fall below 83°, revealingly as we can see in both cases in the winter months my 88° thermostat never actually allows the coolant to hit the correct value of 88°.
These are true temperature readings taken from my Canems software not the rather inaccurate figures we see from our TVR temp gauge, the fact my 88° thermostat equipped Rover V8 never actually hits the target 88° coolant temp at speed on a winter's day proves the system overall is over cooling and the air cooling effect on the engine block is real. Now consider what happens if you have unwisely fitted a 77° thermostat, the low value stat will open and bring the radiator way to early, so much so you'll probably find the coolant will never get above 70° (or even lower) which will mean the engine management system will never break out of it's warm up enrichment mode.
Also keep in mind the thermostat will start to open well below the value stamped on it, and will never actually be fully open until the coolant temp is some way above the stat's marked value, the value marked on the stat is what the engine coolant should be controlled at under all normal running conditions with the exception of idle. On a cold day the radiator is essentially a huge vessel of super cold coolant so even if the thermostat only opens a tiny amount it will have a far more dramatic and rapid effect on dropping the coolant temp within the block compared with the same volume of warm coolant sitting in the rad on a summer's day when ambient temps are far higher.
To be honest all engine coolant systems are a compromise which is why they can only be expected to work within a range of temps, in an ideal world coolant would hit 98° and never stray one degree above or below this figure no matter what, modern engines are far better at this because they often use an electric thermostat which is faster acting than the old wax type we use. A mechanical water pump that just pumps harder and harder the faster the engine turns is also a huge compromise because at speed on a cold day the engine may not even need a water pump at all, what you really want s the opposite of what a mechanical pump does. Ideally you want a pump that spins fast at low engine speeds (idle) and a far slower turning pump or no pump at all at speed. This is where an electric water pump can deliver a huge improvement in efficiency and will also help to maintain the correct coolant temp at all times where a mechanical water pump will often promote over cooling even with the correct value stat fitted and it will most definitely be wasting fuel.
A radiator blind is an ancient solution to the issues of coolant system compromise, it's really just a sticking plaster solution but rad blinds can work very well indeed. The trouble is you typically only need to help of a rad blind at speed, at idle it may promote overheating so do be careful how much of the rad you cover. In an ideal world the blind would only come into play above 40mph so something with sprung slats that are forced closed by increasing airflow as road speed increases and will open again automatically when airflow (road speed) drops would be the perfect solution.
Of course such systems are not new, back in the 1920'/30's it was common to see thermostatically controlled grill slats that opened when coolant temps increased above a certain threshold and closed when coolant temps dropped to restrict the effects of airflow over the radiator. This YouTube link shows such a mechanism used on a 1936 Talbot, the owner has just replacing the slow bellows type thermostat used on the original system with a modern fast acting electric actuator, this clearly works extremely well.
https://www.youtube.com/watch?v=MemeDpyp61M
To be 100% clear, if your car overheats you have an issue with your cooling system that needs investigating and correcting, fitting a lower value thermostat is not going to help because the function of the stat is merely to help the engine warm up and reach it's optimal coolant temp faster.
A 77° thermostat is fully open around 80°, engines don't overheat at 80° any more than they overheat at 93° when my 88° thermostat is fully open, in both examples neither engine even comes close to overheating which on a pressure sealed system can only occur above 105° and in reality more likely closer to 110°.
The capacity of the coolant system, the surface area of the radiator and the airflow through it is what governs the running coolant temp not the thermostat, at idle the car is stationary so the missing airflow generated by the car moving forward is replaced by the radiator fans. Given this and the fact the capacity of the coolant system and surface area of the rad in an engine fitted with a 77° thermostat is exactly the same as the engine fitted with 88° thermostat, neither stat will make a jot of difference to the engine's propensity to overheat or ability to control over heating.
However it should be noted the Rover V8 being an aluminum block engine is very good a dissipating heat all by itself, this is especially true when the engine is subject to high levels of cooling airflow rushing over it in the winter months when the car is driven at speed.
If you fit a 77° thermostat it will open way too soon so the radiator will come into play way too early, this will be especially noticeable in the winter months as the air cooled ally block effect will compound the issue. During the winter you want the coolant to remain trapped in the block and heater as long as possible before the stat starts to open to bring the radiator into the equation, a stat that opens too soon will just mean coolant temps will never get to the correct running target of 90°.
To be honest in the winter the engine may well never get up to full operating temp even with an 88° thermostat fitted due to the cooling effect of all that icy wind blast over the block. As I say I have run an 88° thermostat for years, without a rad blind fitted the engine will still struggle to get above 80° during a fast motorway run.
Without a rad blind in the winter months the over cooling issue can be directly linked to how soon after starting the cold engine I reach those higher speed cruising speeds. If I join the motorway too soon after a cold start my coolant temp will take ages just to eventually hit 80°, however it I join the motorway with a fully warmed engine the coolant will never fall below 83°, revealingly as we can see in both cases in the winter months my 88° thermostat never actually allows the coolant to hit the correct value of 88°.
These are true temperature readings taken from my Canems software not the rather inaccurate figures we see from our TVR temp gauge, the fact my 88° thermostat equipped Rover V8 never actually hits the target 88° coolant temp at speed on a winter's day proves the system overall is over cooling and the air cooling effect on the engine block is real. Now consider what happens if you have unwisely fitted a 77° thermostat, the low value stat will open and bring the radiator way to early, so much so you'll probably find the coolant will never get above 70° (or even lower) which will mean the engine management system will never break out of it's warm up enrichment mode.
Also keep in mind the thermostat will start to open well below the value stamped on it, and will never actually be fully open until the coolant temp is some way above the stat's marked value, the value marked on the stat is what the engine coolant should be controlled at under all normal running conditions with the exception of idle. On a cold day the radiator is essentially a huge vessel of super cold coolant so even if the thermostat only opens a tiny amount it will have a far more dramatic and rapid effect on dropping the coolant temp within the block compared with the same volume of warm coolant sitting in the rad on a summer's day when ambient temps are far higher.
To be honest all engine coolant systems are a compromise which is why they can only be expected to work within a range of temps, in an ideal world coolant would hit 98° and never stray one degree above or below this figure no matter what, modern engines are far better at this because they often use an electric thermostat which is faster acting than the old wax type we use. A mechanical water pump that just pumps harder and harder the faster the engine turns is also a huge compromise because at speed on a cold day the engine may not even need a water pump at all, what you really want s the opposite of what a mechanical pump does. Ideally you want a pump that spins fast at low engine speeds (idle) and a far slower turning pump or no pump at all at speed. This is where an electric water pump can deliver a huge improvement in efficiency and will also help to maintain the correct coolant temp at all times where a mechanical water pump will often promote over cooling even with the correct value stat fitted and it will most definitely be wasting fuel.
A radiator blind is an ancient solution to the issues of coolant system compromise, it's really just a sticking plaster solution but rad blinds can work very well indeed. The trouble is you typically only need to help of a rad blind at speed, at idle it may promote overheating so do be careful how much of the rad you cover. In an ideal world the blind would only come into play above 40mph so something with sprung slats that are forced closed by increasing airflow as road speed increases and will open again automatically when airflow (road speed) drops would be the perfect solution.
Of course such systems are not new, back in the 1920'/30's it was common to see thermostatically controlled grill slats that opened when coolant temps increased above a certain threshold and closed when coolant temps dropped to restrict the effects of airflow over the radiator. This YouTube link shows such a mechanism used on a 1936 Talbot, the owner has just replacing the slow bellows type thermostat used on the original system with a modern fast acting electric actuator, this clearly works extremely well.
https://www.youtube.com/watch?v=MemeDpyp61M
I've been out on a run today with outside temps around 9 degrees and getting up to speed straight away I was only hitting 70 degrees on the temp gauge.
It's been noticeably lower since moving to full vacuum on the distributor, was closer to 90 before.
Car runs sweet as a nut but maybe these running temps are slightly too low.
It's been noticeably lower since moving to full vacuum on the distributor, was closer to 90 before.
Car runs sweet as a nut but maybe these running temps are slightly too low.
Belle427 said:
I've been out on a run today with outside temps around 9 degrees and getting up to speed straight away I was only hitting 70 degrees on the temp gauge.
It's been noticeably lower since moving to full vacuum on the distributor, was closer to 90 before.
Car runs sweet as a nut but maybe these running temps are slightly too low.
I seriously wouldn't trust the TVR temp gauge, what it shows is more of an indication of approximate coolant temp rather tan a true and accurate reading.It's been noticeably lower since moving to full vacuum on the distributor, was closer to 90 before.
Car runs sweet as a nut but maybe these running temps are slightly too low.
By design swapping the vac advance unit to a full vacuum signal is only ever going to change the ignition timing at and just off idle, the additional timing it gives will reduce exhaust manifold temps but not really coolant temps, and only really at idle so I doubt it's having much if any impact on overall running temps.
ChimpOnGas said:
I've run an 88° thermostat for years with great results and at no risk whatsoever, I do so because it's the stat value the engine was designed to work with. People still seem to misunderstand how a thermostat works and its function in the cooling system, so you often see low value stats fitted to TVR's in the hope they may somehow magically help with overheating issues.
To be 100% clear, if your car overheats you have an issue with your cooling system that needs investigating and correcting, fitting a lower value thermostat is not going to help because the function of the stat is merely to help the engine warm up and reach it's optimal coolant temp faster.
A 77° thermostat is fully open around 80°, engines don't overheat at 80° any more than they overheat at 93° when my 88° thermostat is fully open, in both examples neither engine even comes close to overheating which on a pressure sealed system can only occur above 105° and in reality more likely closer to 110°.
The capacity of the coolant system, the surface area of the radiator and the airflow through it is what governs the running coolant temp not the thermostat, at idle the car is stationary so the missing airflow generated by the car moving forward is replaced by the radiator fans. Given this and the fact the capacity of the coolant system and surface area of the rad in an engine fitted with a 77° thermostat is exactly the same as the engine fitted with 88° thermostat, neither stat will make a jot of difference to the engine's propensity to overheat or ability to control over heating.
However it should be noted the Rover V8 being an aluminum block engine is very good a dissipating heat all by itself, this is especially true when the engine is subject to high levels of cooling airflow rushing over it in the winter months when the car is driven at speed.
If you fit a 77° thermostat it will open way too soon so the radiator will come into play way too early, this will be especially noticeable in the winter months as the air cooled ally block effect will compound the issue. During the winter you want the coolant to remain trapped in the block and heater as long as possible before the stat starts to open to bring the radiator into the equation, a stat that opens too soon will just mean coolant temps will never get to the correct running target of 90°.
To be honest in the winter the engine may well never get up to full operating temp even with an 88° thermostat fitted due to the cooling effect of all that icy wind blast over the block. As I say I have run an 88° thermostat for years, without a rad blind fitted the engine will still struggle to get above 80° during a fast motorway run.
Without a rad blind in the winter months the over cooling issue can be directly linked to how soon after starting the cold engine I reach those higher speed cruising speeds. If I join the motorway too soon after a cold start my coolant temp will take ages just to eventually hit 80°, however it I join the motorway with a fully warmed engine the coolant will never fall below 83°, revealingly as we can see in both cases in the winter months my 88° thermostat never actually allows the coolant to hit the correct value of 88°.
These are true temperature readings taken from my Canems software not the rather inaccurate figures we see from our TVR temp gauge, the fact my 88° thermostat equipped Rover V8 never actually hits the target 88° coolant temp at speed on a winter's day proves the system overall is over cooling and the air cooling effect on the engine block is real. Now consider what happens if you have unwisely fitted a 77° thermostat, the low value stat will open and bring the radiator way to early, so much so you'll probably find the coolant will never get above 70° (or even lower) which will mean the engine management system will never break out of it's warm up enrichment mode.
Also keep in mind the thermostat will start to open well below the value stamped on it, and will never actually be fully open until the coolant temp is some way above the stat's marked value, the value marked on the stat is what the engine coolant should be controlled at under all normal running conditions with the exception of idle. On a cold day the radiator is essentially a huge vessel of super cold coolant so even if the thermostat only opens a tiny amount it will have a far more dramatic and rapid effect on dropping the coolant temp within the block compared with the same volume of warm coolant sitting in the rad on a summer's day when ambient temps are far higher.
To be honest all engine coolant systems are a compromise which is why they can only be expected to work within a range of temps, in an ideal world coolant would hit 98° and never stray one degree above or below this figure no matter what, modern engines are far better at this because they often use an electric thermostat which is faster acting than the old wax type we use. A mechanical water pump that just pumps harder and harder the faster the engine turns is also a huge compromise because at speed on a cold day the engine may not even need a water pump at all, what you really want s the opposite of what a mechanical pump does. Ideally you want a pump that spins fast at low engine speeds (idle) and a far slower turning pump or no pump at all at speed. This is where an electric water pump can deliver a huge improvement in efficiency and will also help to maintain the correct coolant temp at all times where a mechanical water pump will often promote over cooling even with the correct value stat fitted and it will most definitely be wasting fuel.
A radiator blind is an ancient solution to the issues of coolant system compromise, it's really just a sticking plaster solution but rad blinds can work very well indeed. The trouble is you typically only need to help of a rad blind at speed, at idle it may promote overheating so do be careful how much of the rad you cover. In an ideal world the blind would only come into play above 40mph so something with sprung slats that are forced closed by increasing airflow as road speed increases and will open again automatically when airflow (road speed) drops would be the perfect solution.
Of course such systems are not new, back in the 1920'/30's it was common to see thermostatically controlled grill slats that opened when coolant temps increased above a certain threshold and closed when coolant temps dropped to restrict the effects of airflow over the radiator. This YouTube link shows such a mechanism used on a 1936 Talbot, the owner has just replacing the slow bellows type thermostat used on the original system with a modern fast acting electric actuator, this clearly works extremely well.
https://www.youtube.com/watch?v=MemeDpyp61M
Thanks Dave - that was very good info, am going to change the thermostat as believe it to be original 94 year and going to fit an 88 deg part - like you have never had an overheating issue except when caused by a failed part.To be 100% clear, if your car overheats you have an issue with your cooling system that needs investigating and correcting, fitting a lower value thermostat is not going to help because the function of the stat is merely to help the engine warm up and reach it's optimal coolant temp faster.
A 77° thermostat is fully open around 80°, engines don't overheat at 80° any more than they overheat at 93° when my 88° thermostat is fully open, in both examples neither engine even comes close to overheating which on a pressure sealed system can only occur above 105° and in reality more likely closer to 110°.
The capacity of the coolant system, the surface area of the radiator and the airflow through it is what governs the running coolant temp not the thermostat, at idle the car is stationary so the missing airflow generated by the car moving forward is replaced by the radiator fans. Given this and the fact the capacity of the coolant system and surface area of the rad in an engine fitted with a 77° thermostat is exactly the same as the engine fitted with 88° thermostat, neither stat will make a jot of difference to the engine's propensity to overheat or ability to control over heating.
However it should be noted the Rover V8 being an aluminum block engine is very good a dissipating heat all by itself, this is especially true when the engine is subject to high levels of cooling airflow rushing over it in the winter months when the car is driven at speed.
If you fit a 77° thermostat it will open way too soon so the radiator will come into play way too early, this will be especially noticeable in the winter months as the air cooled ally block effect will compound the issue. During the winter you want the coolant to remain trapped in the block and heater as long as possible before the stat starts to open to bring the radiator into the equation, a stat that opens too soon will just mean coolant temps will never get to the correct running target of 90°.
To be honest in the winter the engine may well never get up to full operating temp even with an 88° thermostat fitted due to the cooling effect of all that icy wind blast over the block. As I say I have run an 88° thermostat for years, without a rad blind fitted the engine will still struggle to get above 80° during a fast motorway run.
Without a rad blind in the winter months the over cooling issue can be directly linked to how soon after starting the cold engine I reach those higher speed cruising speeds. If I join the motorway too soon after a cold start my coolant temp will take ages just to eventually hit 80°, however it I join the motorway with a fully warmed engine the coolant will never fall below 83°, revealingly as we can see in both cases in the winter months my 88° thermostat never actually allows the coolant to hit the correct value of 88°.
These are true temperature readings taken from my Canems software not the rather inaccurate figures we see from our TVR temp gauge, the fact my 88° thermostat equipped Rover V8 never actually hits the target 88° coolant temp at speed on a winter's day proves the system overall is over cooling and the air cooling effect on the engine block is real. Now consider what happens if you have unwisely fitted a 77° thermostat, the low value stat will open and bring the radiator way to early, so much so you'll probably find the coolant will never get above 70° (or even lower) which will mean the engine management system will never break out of it's warm up enrichment mode.
Also keep in mind the thermostat will start to open well below the value stamped on it, and will never actually be fully open until the coolant temp is some way above the stat's marked value, the value marked on the stat is what the engine coolant should be controlled at under all normal running conditions with the exception of idle. On a cold day the radiator is essentially a huge vessel of super cold coolant so even if the thermostat only opens a tiny amount it will have a far more dramatic and rapid effect on dropping the coolant temp within the block compared with the same volume of warm coolant sitting in the rad on a summer's day when ambient temps are far higher.
To be honest all engine coolant systems are a compromise which is why they can only be expected to work within a range of temps, in an ideal world coolant would hit 98° and never stray one degree above or below this figure no matter what, modern engines are far better at this because they often use an electric thermostat which is faster acting than the old wax type we use. A mechanical water pump that just pumps harder and harder the faster the engine turns is also a huge compromise because at speed on a cold day the engine may not even need a water pump at all, what you really want s the opposite of what a mechanical pump does. Ideally you want a pump that spins fast at low engine speeds (idle) and a far slower turning pump or no pump at all at speed. This is where an electric water pump can deliver a huge improvement in efficiency and will also help to maintain the correct coolant temp at all times where a mechanical water pump will often promote over cooling even with the correct value stat fitted and it will most definitely be wasting fuel.
A radiator blind is an ancient solution to the issues of coolant system compromise, it's really just a sticking plaster solution but rad blinds can work very well indeed. The trouble is you typically only need to help of a rad blind at speed, at idle it may promote overheating so do be careful how much of the rad you cover. In an ideal world the blind would only come into play above 40mph so something with sprung slats that are forced closed by increasing airflow as road speed increases and will open again automatically when airflow (road speed) drops would be the perfect solution.
Of course such systems are not new, back in the 1920'/30's it was common to see thermostatically controlled grill slats that opened when coolant temps increased above a certain threshold and closed when coolant temps dropped to restrict the effects of airflow over the radiator. This YouTube link shows such a mechanism used on a 1936 Talbot, the owner has just replacing the slow bellows type thermostat used on the original system with a modern fast acting electric actuator, this clearly works extremely well.
https://www.youtube.com/watch?v=MemeDpyp61M
The gauge seems to work quite well, fans come on and off just before showing 90deg so will leave this as is, but going to explore an active blind, like the idea of using an actuator like on the Talbot and will look at using the otter switch to open - maybe with a manual summer/winter setting allowing for the blind to have less restriction when closed in summer mode.
Its quite possible the thermostat is not working correct, would have thought they fail closed, but running at this hotter temp transformed the fueling and it runs so much better - these cars have so much grunt they can hide a little problem so well
Thanks again Dave for the post
Just a slight different slant on this. I have owned my Chim for 12 years and have always run a lower temp stat. Car runs brilliant and always has, emissions on the MOT are always on the lower end of the limits so the ECU doesn’t mind this stat. Plugs are always the correct colour.
The reason I have a lower temp stat is a report I read when I first got the car and it was advised to run the engine at the lower end of the temp range. This was to reduce the possibility of liner slip.
It was not fitted for overheating issues. The Steve Heath bible states the optimum temp is 74-95.
It’s probablyy advisable normally to run an engine at the upper end of the range but I made the decision years ago and have no regrets at all..
I don’t believe the gauge but a toasty heater when outside temp is very cold is a good indicator
The reason I have a lower temp stat is a report I read when I first got the car and it was advised to run the engine at the lower end of the temp range. This was to reduce the possibility of liner slip.
It was not fitted for overheating issues. The Steve Heath bible states the optimum temp is 74-95.
It’s probablyy advisable normally to run an engine at the upper end of the range but I made the decision years ago and have no regrets at all..
I don’t believe the gauge but a toasty heater when outside temp is very cold is a good indicator
My own experience is an over-reading water temp gauge.
If I plug into the Canems ECU, the water temp used for turning on the fans (from the 'other' sensor) shows 80C when the dash gauge shows 90C. It really is just an approximate indication.
On cool days at cruise, it shows only 70C so the engine water temp is only 60C! Enough for a warm heater though.
If I plug into the Canems ECU, the water temp used for turning on the fans (from the 'other' sensor) shows 80C when the dash gauge shows 90C. It really is just an approximate indication.
On cool days at cruise, it shows only 70C so the engine water temp is only 60C! Enough for a warm heater though.
ChimpOnGas said:
I seriously wouldn't trust the TVR temp gauge, what it shows is more of an indication of approximate coolant temp rather tan a true and accurate reading.
^^This^^People quoting absolute numbers from the dash gauge is worrying. Hopefully owners realise that the ECU does not use this sender for its fuelling calculation. If you really want to know what your coolant temperature is and more importantly what your ECU is doing about that then connect rovergauge so you can read from the more accurate and faster responding ECU temperature sender.
As COG says, the dash gauge is only an indication, imo the gauge should sweep a blue to red scale without numbers so that drivers arn't given inaccurate information
Talking about rad shrouds didn’t Jag use a simple flap type system on the XJ6 saloon.
Just rubber flaps that pushed shut when over a certain speed,,, or did I just make that up, i has a glorious series 3 once and I happened to notice them and assumed that’s how they must have worked?
If I’m correct it might be a good idea to look into how that actually worked as it looked very simple and the Jagggg never ran to cool.
Just rubber flaps that pushed shut when over a certain speed,,, or did I just make that up, i has a glorious series 3 once and I happened to notice them and assumed that’s how they must have worked?
If I’m correct it might be a good idea to look into how that actually worked as it looked very simple and the Jagggg never ran to cool.
There are some mutterings in the RV8 tuning manuals that the engine produces better power at lower temperatures, so this may be a reason cooler 'stats have been fitted by some. This idea makes no sense to me, as you want to extract heat into the combustion chamber to push the piston down, and not waste it in the cooling system and into the atmosphere. I can only assume there are other factors (maybe friction) that causes the available power to drop as the engine reaches the mid 90's.
Classic Chim said:
Talking about rad shrouds didn’t Jag use a simple flap type system on the XJ6 saloon.
Just rubber flaps that pushed shut when over a certain speed,,, or did I just make that up, i has a glorious series 3 once and I happened to notice them and assumed that’s how they must have worked?
If I’m correct it might be a good idea to look into how that actually worked as it looked very simple and the Jagggg never ran to cool.
this is funny Alun, I own a glorious series 3 jag and hav never noticed "rubber flaps" on the fan shroud [although i have seen them on other cars] I just had a look at mine and sure enough it has the flaps. only thing is they are on the rear side of the shroud so they would presumably blow open at speed not closed as you would think was required? i imagine they are there so that when the thermo fan cuts in at low speeds the flaps will pull shut and so draw air through the whole radiator and still proved good air flow through the rad. at higher speed.Just rubber flaps that pushed shut when over a certain speed,,, or did I just make that up, i has a glorious series 3 once and I happened to notice them and assumed that’s how they must have worked?
If I’m correct it might be a good idea to look into how that actually worked as it looked very simple and the Jagggg never ran to cool.
Hahah, so in the Jags case it works the other way round, I knew it did something 
I think I was polishing the front lower valance at the time so only sort of noticed them by chance. This thread then reminded me of it all those years ago.
Thanks for clearing that up as I was quite shocked at the time
I think I was polishing the front lower valance at the time so only sort of noticed them by chance. This thread then reminded me of it all those years ago.
Thanks for clearing that up as I was quite shocked at the time
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