does anyone know what temperature the thermostat opens and also when an electric fan should cut in? neither my engine nor rad has a fan switch, only that aircon fan switch which is no good as i think it cuts in at 110 deg's.
i think i will have to plum in a sensor from a different car in one of the pipes.
Ralph
edit, its a 3.5 V8 from a Range Rover.
what temp for thermostat/fan switch
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Depends on the 'stat. Normally they are specced at 82deg or 88deg, but I think that's when they start to open, and it takes a few degrees for them to become fully open.
There are various ways of controlling the fan, normally by sticking a temp sensor in the bottom (or top) hose and using some kind of control box. There are kits out there to do it....... I'm sure somebody will know where they can be purchased from.
Chris.
There are various ways of controlling the fan, normally by sticking a temp sensor in the bottom (or top) hose and using some kind of control box. There are kits out there to do it....... I'm sure somebody will know where they can be purchased from.
Chris.
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Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
ideal thats probly same as the rover k series temps then, they started off life with a 82 deg stat, and the rad fan turns on at 90 something, then back off when its bellow 86.
then for emissions purposes they started using a 88 deg stat, which was silly as in therie the fan would never turn off as it would fight the thermostat.
i will sue a fan switch from a car then an make a thing for it to go in to.
Ralph
then for emissions purposes they started using a 88 deg stat, which was silly as in therie the fan would never turn off as it would fight the thermostat.
i will sue a fan switch from a car then an make a thing for it to go in to.
Ralph
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Ian Anderson
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Ralph
The cooler thermostat would be better
Try to pick up a Ford Thermostat from a Scrappy - they are the cheapest to replace if they go faulty. Be sure to cut a bit of the loom off too so you get the connector plug! Also they can be had in different temp ranges
The fan switch can be used direct to the fan but the fan current draw will quickly burn out the contacts so better to run it through a relay.
Lastly wire up an override switch so you can turn it on manually - you can see the traffic jam ahead! It then gives the engine a bit more of a chance on not boiling over! Especially on rear engined ones where there is little to no air movement around the engine when moving slowly.
It may pay to wire a second fan in the engine bay to blow air in or extract hot air in the same circuit
Ian
The cooler thermostat would be better
Try to pick up a Ford Thermostat from a Scrappy - they are the cheapest to replace if they go faulty. Be sure to cut a bit of the loom off too so you get the connector plug! Also they can be had in different temp ranges
The fan switch can be used direct to the fan but the fan current draw will quickly burn out the contacts so better to run it through a relay.
Lastly wire up an override switch so you can turn it on manually - you can see the traffic jam ahead! It then gives the engine a bit more of a chance on not boiling over! Especially on rear engined ones where there is little to no air movement around the engine when moving slowly.
It may pay to wire a second fan in the engine bay to blow air in or extract hot air in the same circuit
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
guessing this would be an ideal thermostat, i dont think i need to go any lower than 82. an if i have trouble with engine bay temps i will definatly rig up an engine bay fan to off the fan switch as well as rad fan.
Ralph
edit ment to put up this link... http://cgi.ebay.co.uk/ROVER-V8-THERMOST ... .m20.l1116
Ralph
edit ment to put up this link... http://cgi.ebay.co.uk/ROVER-V8-THERMOST ... .m20.l1116
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Ian Anderson
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No I ment a ford Fan switch
Like this sort of thing
http://cgi.ebay.co.uk/Ford-scorpio-Gran ... 286.c0.m14
They screw into a nut (about12mm) welded in the radiator (or in the solid pipes runing to / from the rad)
Then depending on the placement atemperature range is decided for the on / off switching (Water will be hotter entering the rad than leaving it so hence the need to decide placement first han chose the "switch" to match.
This purely has 2 wires coming our of it and switches a circuit for the fan/s
On mine the fan switch is mounted in the rad but near the exit point It switches on when the water temp is about 95 and off again at 90 ish
And on manual switch it will never go above 86
Ian
Like this sort of thing
http://cgi.ebay.co.uk/Ford-scorpio-Gran ... 286.c0.m14
They screw into a nut (about12mm) welded in the radiator (or in the solid pipes runing to / from the rad)
Then depending on the placement atemperature range is decided for the on / off switching (Water will be hotter entering the rad than leaving it so hence the need to decide placement first han chose the "switch" to match.
This purely has 2 wires coming our of it and switches a circuit for the fan/s
On mine the fan switch is mounted in the rad but near the exit point It switches on when the water temp is about 95 and off again at 90 ish
And on manual switch it will never go above 86
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
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ramon alban
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Regarding the original query, I think the best temperature to operate an electric cooling fan would be about 5 degrees C above the intended engine running temperature, so the Thermostat and other cooling functions, Radiator, Viscous, Ram Air, what have you, can be allowed to operate normally.
However I have an observation regarding this thread which I hope comes generally under the heading of "just my two pennyworth" so bear with me, its not a rant.
I'm always a bit bemused why later RV8 owners might choose to run their engines cooler than 90 deg C.
In the Sd1 Vitesse Workshop manual the standard thermostat is specified as 88 deg.
Given that there will be a few degrees of hysteresis as the stat opens, it is clear that the intended Rover running temperature will be in the range 90 to 95 deg C.
There was also the option to fit a "Summer" stat at 82 degrees to give the engine a chance of NOT overheating in hot conditions/climates and thereby mitigate the chances of overheating in the case of a cooling malfunction.
In addition, all Efi owners will be familiar with the temperature sensor resistance table which specified that the sensor will read 300-400 ohms at 80 degrees C and 150-200 ohms at 100 degrees C.
Furthermore, The Rovers Efi Technician Training Manual recommends a "get you home " fix of substituting a faulty temp sensor with a 150-200 ohm resistor to allow the engine to run properly.
So, many things point to the intended RV8 running temperature for the later Efi engines being something over 90 degrees.
If this is so, then choosing to run an engine at a much cooler temperature ---
--- will compromise fuel economy due to rich mixture, friction wear in the combustion chambers due to oil being washed off the bores and the lubricant operating a too low a temperature.
Add to that the obvious problems of inefficient combustion and excess hydrocarbons, in my opinion, it simply does not make sense.
However I have an observation regarding this thread which I hope comes generally under the heading of "just my two pennyworth" so bear with me, its not a rant.
I'm always a bit bemused why later RV8 owners might choose to run their engines cooler than 90 deg C.
In the Sd1 Vitesse Workshop manual the standard thermostat is specified as 88 deg.
Given that there will be a few degrees of hysteresis as the stat opens, it is clear that the intended Rover running temperature will be in the range 90 to 95 deg C.
There was also the option to fit a "Summer" stat at 82 degrees to give the engine a chance of NOT overheating in hot conditions/climates and thereby mitigate the chances of overheating in the case of a cooling malfunction.
In addition, all Efi owners will be familiar with the temperature sensor resistance table which specified that the sensor will read 300-400 ohms at 80 degrees C and 150-200 ohms at 100 degrees C.
Furthermore, The Rovers Efi Technician Training Manual recommends a "get you home " fix of substituting a faulty temp sensor with a 150-200 ohm resistor to allow the engine to run properly.
So, many things point to the intended RV8 running temperature for the later Efi engines being something over 90 degrees.
If this is so, then choosing to run an engine at a much cooler temperature ---
I prefer to use a 74. In winter it might be a touch cool, but for 9 months of the year, especially in traffic, it is just right.
--- will compromise fuel economy due to rich mixture, friction wear in the combustion chambers due to oil being washed off the bores and the lubricant operating a too low a temperature.
Add to that the obvious problems of inefficient combustion and excess hydrocarbons, in my opinion, it simply does not make sense.
I am with you completely on this. The use of low temp stats is only masking problems elsewhere. Of course thats a resonable thing to do if you cant find or fix the problem but its a bandade none the less.ramon alban wrote:Regarding the original query, I think the best temperature to operate an electric cooling fan would be about 5 degrees C above the intended engine running temperature, so the Thermostat and other cooling functions, Radiator, Viscous, Ram Air, what have you, can be allowed to operate normally.
However I have an observation regarding this thread which I hope comes generally under the heading of "just my two pennyworth" so bear with me, its not a rant.
I'm always a bit bemused why later RV8 owners might choose to run their engines cooler than 90 deg C.
In the Sd1 Vitesse Workshop manual the standard thermostat is specified as 88 deg.
Given that there will be a few degrees of hysteresis as the stat opens, it is clear that the intended Rover running temperature will be in the range 90 to 95 deg C.
There was also the option to fit a "Summer" stat at 82 degrees to give the engine a chance of NOT overheating in hot conditions/climates and thereby mitigate the chances of overheating in the case of a cooling malfunction.
In addition, all Efi owners will be familiar with the temperature sensor resistance table which specified that the sensor will read 300-400 ohms at 80 degrees C and 150-200 ohms at 100 degrees C.
Furthermore, The Rovers Efi Technician Training Manual recommends a "get you home " fix of substituting a faulty temp sensor with a 150-200 ohm resistor to allow the engine to run properly.
So, many things point to the intended RV8 running temperature for the later Efi engines being something over 90 degrees.
If this is so, then choosing to run an engine at a much cooler temperature ---
I prefer to use a 74. In winter it might be a touch cool, but for 9 months of the year, especially in traffic, it is just right.
--- will compromise fuel economy due to rich mixture, friction wear in the combustion chambers due to oil being washed off the bores and the lubricant operating a too low a temperature.
Add to that the obvious problems of inefficient combustion and excess hydrocarbons, in my opinion, it simply does not make sense.
I thought that I would eloborate as to why I choose to run a 74 degree thermostat in my Rover V8.
I have been driving my 1974 Rover P6B since 1985. The thermostats slated for the 3500 run between 78 and 83 degrees C. At the time, mine was fitted with an 82.
The temperature gauge has three marked temperatures only,..50, 85 and 120. With an 82, the needle would sit between the 8 and 5, provided the ambient temperature was little more than 20 degrees C. In traffic or on warmer days, especially here in Sydney when from September to May, 20 degrees C is pretty much a day time minimum, and 30 plus quite often over Summer, the needle would climb much higher, and I estimate between 95 and 100 degrees. My engine oil temperature gauge would read between 110 and 120 degrees on such occassions, and the sender is in the sump plug, reading the oil at its coolest!
In 1988 I had to remove the sump and tighten the majority of the main bearing caps, as due to block expansion they had worked loose..evident by heavy knocking at idle...which was gone once done.
My 3.5 engine in the P6B ran a 10.5 : 1 CR, timing was set to TDC running on less than 100 octane fuel. On occassions when coolant temperature rose above 85 degrees, power would always fall off and pinging would always result, especially in traffic when accelerating.
I changed to a 78 degree thermostat which helped, but on hotter days, the same would occur. I switched over to a 74 degree thermostat, and had the largest radiator that I could fit within the engine bay fitted.
This made a large improvement, but still on days over 30 degrees, temperature would climb...coolant 90 to 100 degrees, oil 100 to 120 degrees!!
Last year, after 205,000 miles (327,000km) I retired my 3.5 and had a 4.6 fitted, running my twin SU carbs. I have a 74 degree thermostat fitted, and an engine oil cooler. My best fuel consumption has been 29mpg, the worst 24 mpg, both country running, the better being on a cooler day.
Inspection of the 3.5 engine revealed all bar 2 of the bolts securing the main bearing caps had worked loose and were below the minimum specified torque setting. All block registers showed fretting in varying degrees.
I read Des Hammill's text last year before changing my engine, and the constant theme of running the Rover V8 at no more than 80 degrees C seemed quite appropriate, given what I had found.
Members of the U.K based P6 Rover Owner's club would often submit articles to the club magazine discussing the overheating problems that would effect their cars on warmer days. It is a similar theme with Rover club members here in Sydney, and N.S.W in general.
Everything is a compromise, and over 23 years of driving my Rover, which is a daily runner, I try and do the best I can in the conditions that I am required to operate.
I have been driving my 1974 Rover P6B since 1985. The thermostats slated for the 3500 run between 78 and 83 degrees C. At the time, mine was fitted with an 82.
The temperature gauge has three marked temperatures only,..50, 85 and 120. With an 82, the needle would sit between the 8 and 5, provided the ambient temperature was little more than 20 degrees C. In traffic or on warmer days, especially here in Sydney when from September to May, 20 degrees C is pretty much a day time minimum, and 30 plus quite often over Summer, the needle would climb much higher, and I estimate between 95 and 100 degrees. My engine oil temperature gauge would read between 110 and 120 degrees on such occassions, and the sender is in the sump plug, reading the oil at its coolest!
In 1988 I had to remove the sump and tighten the majority of the main bearing caps, as due to block expansion they had worked loose..evident by heavy knocking at idle...which was gone once done.
My 3.5 engine in the P6B ran a 10.5 : 1 CR, timing was set to TDC running on less than 100 octane fuel. On occassions when coolant temperature rose above 85 degrees, power would always fall off and pinging would always result, especially in traffic when accelerating.
I changed to a 78 degree thermostat which helped, but on hotter days, the same would occur. I switched over to a 74 degree thermostat, and had the largest radiator that I could fit within the engine bay fitted.
This made a large improvement, but still on days over 30 degrees, temperature would climb...coolant 90 to 100 degrees, oil 100 to 120 degrees!!
Last year, after 205,000 miles (327,000km) I retired my 3.5 and had a 4.6 fitted, running my twin SU carbs. I have a 74 degree thermostat fitted, and an engine oil cooler. My best fuel consumption has been 29mpg, the worst 24 mpg, both country running, the better being on a cooler day.
Inspection of the 3.5 engine revealed all bar 2 of the bolts securing the main bearing caps had worked loose and were below the minimum specified torque setting. All block registers showed fretting in varying degrees.
I read Des Hammill's text last year before changing my engine, and the constant theme of running the Rover V8 at no more than 80 degrees C seemed quite appropriate, given what I had found.
Members of the U.K based P6 Rover Owner's club would often submit articles to the club magazine discussing the overheating problems that would effect their cars on warmer days. It is a similar theme with Rover club members here in Sydney, and N.S.W in general.
Everything is a compromise, and over 23 years of driving my Rover, which is a daily runner, I try and do the best I can in the conditions that I am required to operate.
4.6 Rover 3500 P6B
only thign with trying to make it colder is im sure in therie, at 95 degree's surely any 78/82/88 degree thermostats will be fully open??
i would have thoguht if its runnign far hotter than the thermostat is rated to then theres a further problem like the rads to small, or the water pump is not up to the job?
Ralph
i would have thoguht if its runnign far hotter than the thermostat is rated to then theres a further problem like the rads to small, or the water pump is not up to the job?
Ralph
Hello Ralph,
One accessory I don't have on my P6B are thermatic fans, mainly because there is simply no room. Between the radiator, which is the largest that will fit in the space provided, and the grill is a very narrow space, and I have a transmission oil cooler there.
The standard fan has 13 blades and runs on a viscous coupling. I have changed the coupling previously, but when the weather is hot the temperature goes up.
Sitting in traffic idling, or driving slowly is the problem. A large engine in a small space, with insufficient air flow.
Ron.
One accessory I don't have on my P6B are thermatic fans, mainly because there is simply no room. Between the radiator, which is the largest that will fit in the space provided, and the grill is a very narrow space, and I have a transmission oil cooler there.
The standard fan has 13 blades and runs on a viscous coupling. I have changed the coupling previously, but when the weather is hot the temperature goes up.
Sitting in traffic idling, or driving slowly is the problem. A large engine in a small space, with insufficient air flow.
Ron.
4.6 Rover 3500 P6B
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Ian Anderson
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I have to agree with Ron here
you will need airflow around your engine
I cannot believe how much lower the temp is on my firewall (left shoulder about 1 inch from it) with and without the 2 fans running blowing the air through the engine bay when in traffic / stationary Heat bakes off it without the fans running and with them running "comfortably warm"
Ian
you will need airflow around your engine
I cannot believe how much lower the temp is on my firewall (left shoulder about 1 inch from it) with and without the 2 fans running blowing the air through the engine bay when in traffic / stationary Heat bakes off it without the fans running and with them running "comfortably warm"
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
