Discussion
So taking the car out on (yet another) shakedown run this week (picked a buddy up from T5 at Heathrow - must be the most unlikely Airport pickup car 
), and whilst in traffic my water temperatures were rising REALLY quick.
When running normally the gauge reads 80. Sat in traffic (with the fans cutting in) the temp was quickly up to 110+ - i had to get home so didn't experiment to see whether it stabilised there but clearly I'm not shedding heat as quickly as I should or would like. I read a couple of threads regards the Pacet 11inch fan upgrades only to find that Kenlowe bought them out a couple of years ago. I saw Mark's electric fan upgrade (which I like) but it's not a practical solution given all the grief I had last year upgrading my charging system (which is powered off the water pump) and I will remove the grill behind the fans this weekend. The coolant system is in good nick and was refilled last year with new antifreeze.
So here's a couple of questions:
- I'll phone the factory at some point but do they offer a more powerful fan option? My Peter Knight engine is so far away from 'factory spec', we laugh about it when we get on the the phone to discuss what the factory advises!
- Has anyone fitted one of the Kenlow Extreme Performance Fans and if so is the 12" an alternative with modifications to the shroud?
I spoke with Kenlowe yesterday (very helpful BTW) and they are sending me the specs/sized for both the 11 & 12 inch options - the current draw is 15 and 24 amps per fan respectively - this is HUGE, so obviously the wiring will be a concern. The way the guy there explained the upgrading fan option made sense. He said that the lower amp fans lose a great deal of their power (sucking efficiency) when asked to draw air through a dense rad thus you need a much more powerful fan in order to dump heat out of the rad, meaning it runs for less time.... net cost of buying to new fans inc delivery and VAT is around £270-290 dependent upon the option.
I've no issue spending the money - way cheaper than an engine rebuild and an acceptable cost to allay any temperature anxiety I'll have (ambient temp on Monday was only around 19C and we weren't stuck in any MAJOR traffic!).
), and whilst in traffic my water temperatures were rising REALLY quick.When running normally the gauge reads 80. Sat in traffic (with the fans cutting in) the temp was quickly up to 110+ - i had to get home so didn't experiment to see whether it stabilised there but clearly I'm not shedding heat as quickly as I should or would like. I read a couple of threads regards the Pacet 11inch fan upgrades only to find that Kenlowe bought them out a couple of years ago. I saw Mark's electric fan upgrade (which I like) but it's not a practical solution given all the grief I had last year upgrading my charging system (which is powered off the water pump) and I will remove the grill behind the fans this weekend. The coolant system is in good nick and was refilled last year with new antifreeze.
So here's a couple of questions:
- I'll phone the factory at some point but do they offer a more powerful fan option? My Peter Knight engine is so far away from 'factory spec', we laugh about it when we get on the the phone to discuss what the factory advises!
- Has anyone fitted one of the Kenlow Extreme Performance Fans and if so is the 12" an alternative with modifications to the shroud?
I spoke with Kenlowe yesterday (very helpful BTW) and they are sending me the specs/sized for both the 11 & 12 inch options - the current draw is 15 and 24 amps per fan respectively - this is HUGE, so obviously the wiring will be a concern. The way the guy there explained the upgrading fan option made sense. He said that the lower amp fans lose a great deal of their power (sucking efficiency) when asked to draw air through a dense rad thus you need a much more powerful fan in order to dump heat out of the rad, meaning it runs for less time.... net cost of buying to new fans inc delivery and VAT is around £270-290 dependent upon the option.
I've no issue spending the money - way cheaper than an engine rebuild and an acceptable cost to allay any temperature anxiety I'll have (ambient temp on Monday was only around 19C and we weren't stuck in any MAJOR traffic!).
Hi Nigel I experienced the same issues with mine in traffic I played about for over a year trying fans heat wraps and coatings removing thermostat etc . And in the end it turned out to be that below 2000 rpm the car was running too lead with the fuel mixture May be worth a try on the dyno . I was pulling my hair out trying to cure it P
So caps are all good, as are all the pipes, clips and coolant levels. As to the mixture this can't be a million miles out given it was only on the rolling road 150 miles ago, its fuel injected and I've not so much as looked at it!
My thinking regards fans was an aluminium SBC with 6.75 litres/640 bhp would be beyond the parameters that the factory would have considered. Yes I know that they install bigger/more powerful lumps - but these are modern engines not lumpy, over cam'ed clunkers like mine
My thinking regards fans was an aluminium SBC with 6.75 litres/640 bhp would be beyond the parameters that the factory would have considered. Yes I know that they install bigger/more powerful lumps - but these are modern engines not lumpy, over cam'ed clunkers like mine
Nabbott said:
So caps are all good, as are all the pipes, clips and coolant levels. As to the mixture this can't be a million miles out given it was only on the rolling road 150 miles ago, its fuel injected and I've not so much as looked at it!
My thinking regards fans was an aluminium SBC with 6.75 litres/640 bhp would be beyond the parameters that the factory would have considered. Yes I know that they install bigger/more powerful lumps - but these are modern engines not lumpy, over cam'ed clunkers like mine
Surely if you are idling it shouldn't really matter how much power your engine can make at full chat as it will be making NO power at all anyway. So the amount of heat generated will also be very low. My thinking regards fans was an aluminium SBC with 6.75 litres/640 bhp would be beyond the parameters that the factory would have considered. Yes I know that they install bigger/more powerful lumps - but these are modern engines not lumpy, over cam'ed clunkers like mine
So it is either not enough air getting over the rad (fans), or an issue with the engine that is causing too much heat to be produced at idle (tune).
Ahh, i must be nearly summer again!
A few important points:
1) 110deg is not "too hot" unless your coolant is leaking all over the floor. Modern engines will run fine at 120degC, and usually have a 1.4bar system pressure that will prevent water lose until at least this point
2) The air to fuel mixture of your engine isn't going to make ANY difference to the temperature of your cooling system. (In fact, running "lean" will help! Less fuel burnt = less heat)
3) Is your coolant temp gauge accurate? I'd bet that in the vast majority of cases it isn't.
4) Electric fans don't really ever "struggle to pull air through a rad" as the pressure loss is infinitesimally small at the flow rates a fan can draw. The usual issue is that they are not properly shrouded and just pull in air from behind the rad, rather than through it
5) Check your system voltage at idle. Often, people gear down things like alternators, if you ar edrawing large currents (with big fans, fuel pumps etc) you may find your alternator can't keep up, and these "powerful" electric fans are only powerful at 14.7V. If you system is dipping into the 12v or lower region, you are loosing 20% of your fan power! In fact, fast idling the engine at say 1200rpm often improves idle cooling performance! (water pump moves more water, alternator generates more power etc)
A few important points:
1) 110deg is not "too hot" unless your coolant is leaking all over the floor. Modern engines will run fine at 120degC, and usually have a 1.4bar system pressure that will prevent water lose until at least this point
2) The air to fuel mixture of your engine isn't going to make ANY difference to the temperature of your cooling system. (In fact, running "lean" will help! Less fuel burnt = less heat)
3) Is your coolant temp gauge accurate? I'd bet that in the vast majority of cases it isn't.
4) Electric fans don't really ever "struggle to pull air through a rad" as the pressure loss is infinitesimally small at the flow rates a fan can draw. The usual issue is that they are not properly shrouded and just pull in air from behind the rad, rather than through it
5) Check your system voltage at idle. Often, people gear down things like alternators, if you ar edrawing large currents (with big fans, fuel pumps etc) you may find your alternator can't keep up, and these "powerful" electric fans are only powerful at 14.7V. If you system is dipping into the 12v or lower region, you are loosing 20% of your fan power! In fact, fast idling the engine at say 1200rpm often improves idle cooling performance! (water pump moves more water, alternator generates more power etc)
Edited by anonymous-user on Wednesday 13th May 10:21
Appreciate that 110 isn't too hot per se - but it was the rate of increase that I saw that worried me. I wasn't stationary for long enough for it to go much further (thank goodness) - but where have all the people gone that said, 'yeah I upgraded the factory fans to Pacit 11" with a greater flow rate and now my overheating is no longer an issue'??????
Nabbott said:
Appreciate that 110 isn't too hot per se - but it was the rate of increase that I saw that worried me. I wasn't stationary for long enough for it to go much further (thank goodness) - but where have all the people gone that said, 'yeah I upgraded the factory fans to Pacit 11" with a greater flow rate and now my overheating is no longer an issue'??????
here!Although I use Evans NPG coolant in a 450 horse SBC I was finding problems keeping the temperature down at 100 or less in traffic using the factory fans. When one wore out I upgraded both to PACETs (no other changes) and I can pretty much hold or reduce the temp at whatever I want. My sport uses slightly smaller fans, so I am using 10" IIRC
Kinda of worried I wont get a replacement now...
I had exactly the same problem. 1st solution was to upgrade fans,improve shrouding and remove the grills to increase airflow. This did not make any difference.
My next move was to replace belt driven water pump with an electric one, remove stat altogether and fit a speed control unit which controls the pump speed with engine temp. Sorted! it also controls fans more accurately by sensing water temp as it leaves the engine and runs on for 2 mins after shut off to remove residual heat. However it is a further draw on the alternator but the 80 amp one that I have is able to cope. You are also able to accurately adjust the temp that the engine runs at.
It is fair to say that the slower the water runs through the rad the more heat it will loose however if the flow is too slow the water coming from the engine(where the temp sensor for the gauge is located) can get very hot and perhaps(because there is no return temp sensor) the water returning is quite cool. This kind of gradient cannot be a good thing. The important thing is that the water temp stabilises before it boils. (as it gets hotter more heat will be shed by the rad)
Enough said. My water temp leaving the engine never goes above 87 now with the control temp set at 85.
My next move was to replace belt driven water pump with an electric one, remove stat altogether and fit a speed control unit which controls the pump speed with engine temp. Sorted! it also controls fans more accurately by sensing water temp as it leaves the engine and runs on for 2 mins after shut off to remove residual heat. However it is a further draw on the alternator but the 80 amp one that I have is able to cope. You are also able to accurately adjust the temp that the engine runs at.
It is fair to say that the slower the water runs through the rad the more heat it will loose however if the flow is too slow the water coming from the engine(where the temp sensor for the gauge is located) can get very hot and perhaps(because there is no return temp sensor) the water returning is quite cool. This kind of gradient cannot be a good thing. The important thing is that the water temp stabilises before it boils. (as it gets hotter more heat will be shed by the rad)
Enough said. My water temp leaving the engine never goes above 87 now with the control temp set at 85.
No difference? Ah man - that sucks!
So I've just pushed the grill out (anyone know what gets rid of that Wurth bonding BTW), and all being well will test the car again tonight.
It's has to be said that if I spend £250 on upgraded fans and it runs no cooler I will be somewhat gutted. As I mentioned. I REALLY don't want to have to go to the electric water pump option as I'll have to revisit my whole alternator drive as well
So I've just pushed the grill out (anyone know what gets rid of that Wurth bonding BTW), and all being well will test the car again tonight.
It's has to be said that if I spend £250 on upgraded fans and it runs no cooler I will be somewhat gutted. As I mentioned. I REALLY don't want to have to go to the electric water pump option as I'll have to revisit my whole alternator drive as well
Doh!
So I'm throwing myself at the mercy of the forum.... Form an orderly queue for ridicule here
Having just pushed the grill out I though I'd test the fans to see how much they chucked out...... Only to find that the RH side fan was not working. Pulled the plug, checked the power, reconnected et voila now 2 working fans dry joint in the connector!
Let's see how we go this evening......
So I'm throwing myself at the mercy of the forum.... Form an orderly queue for ridicule here
Having just pushed the grill out I though I'd test the fans to see how much they chucked out...... Only to find that the RH side fan was not working. Pulled the plug, checked the power, reconnected et voila now 2 working fans dry joint in the connector!
Let's see how we go this evening......
That's a nice cheap fix (you can get electrical connection cleaning spray that helps sort this type of problem).
Shame about the mesh. Heat gun and brake cleaner (not at the same time) are your friends for Worth removal.
I sense temperature at the block and my ecu switches the fans on before the temp rises too much. At tick over it takes a while for the rad sensor to detect the rise and fire up the fans as water flow is quite slow.
Paul
Shame about the mesh. Heat gun and brake cleaner (not at the same time) are your friends for Worth removal.
I sense temperature at the block and my ecu switches the fans on before the temp rises too much. At tick over it takes a while for the rad sensor to detect the rise and fire up the fans as water flow is quite slow.
Paul
This might sound like dumb question but since we're on the subject of cooling systems, my swirl pot has a basic rubber gasket and the expansion bottle has a spring loaded pressure release type cap. But after short runs to test the car or with it idling, the water temp is getting up to about 98 deg and I'm losing coolant from the swirl pot from under the cap. Every time I go back to it when it's cool, the water level in the swirl pot is right at the bottom of the pot and it takes maybe a pint of water to bring it back up...
A) is there an issue with the swirl pot lid... Or...
B) am I over filling the swirl pot and the water level should actually be at the bottom of the pot when the engines cool?
Pete
A) is there an issue with the swirl pot lid... Or...
B) am I over filling the swirl pot and the water level should actually be at the bottom of the pot when the engines cool?
Pete
Thanks Tony, however, when you say your second bottle is a third full, are you talking about the expansion bottle which is the one with just the small hoses attached? On mine, that bottle is empty when it's cold and so is the swirl pot which is the one with the large hoses on it and that's the one that is both leaking at the cap and I'm having to top up with about a pint of water all the time. Is something not quite right with that?
The swirl pot, behind the passenger, should be full, the header or expansion tank, behind the driver, the level varies dependent on how hot the water is, normally full(ish) when up to working temp and a third to a quarter full when cold, that's my understanding.
My swirl pot cap leaks as well, I have bought a couple from Car Builders but they leak after a while. There must be a better alternative?? I guess it's needed as a convenient point to fill the system and to purge air bubbles from the system..."
My swirl pot cap leaks as well, I have bought a couple from Car Builders but they leak after a while. There must be a better alternative?? I guess it's needed as a convenient point to fill the system and to purge air bubbles from the system..."
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