Tuscan Rad Fans On Chimaera
Discussion
Hi guys,
I'm starting to look at rad fans as my O/S one has been blowing relays and occasionally makes a noticeable and monetary "crack" sound as it chimes in. The "Crack" sound suggests it may be time for replacement and while I haven't put my test meter on the suspect fan yet I suspect when I do I'll see a massive spike when it fires up and that's what's been cooking my relays
Working to my policy of "If I'm replacing, I'm upgrading" I seem to remember Tuscan Spal fans from Powers Performance were being used by some Chimaera owners as they shift quite a bit more air.
Has anyone done this mod, if so is it a straight swap?
I'm starting to look at rad fans as my O/S one has been blowing relays and occasionally makes a noticeable and monetary "crack" sound as it chimes in. The "Crack" sound suggests it may be time for replacement and while I haven't put my test meter on the suspect fan yet I suspect when I do I'll see a massive spike when it fires up and that's what's been cooking my relays
Working to my policy of "If I'm replacing, I'm upgrading" I seem to remember Tuscan Spal fans from Powers Performance were being used by some Chimaera owners as they shift quite a bit more air.
Has anyone done this mod, if so is it a straight swap?
Edited by ChimpOnGas on Friday 13th May 08:51
I would be interested to know I bit more about uprated fans. I am looking at fitting a Laminova to mine which will have benefits bringing the oil up to temperature faster and cooling the oil when it gets too hot but will put additional load on the water cooling system.
I have been speaking to TVR Power about the possibility of using their new MBE ECU to soft start the fans, thus avoiding the voltage drop when they kick in. Upgraded fans that shift more air (CFM in the fan world I believe) would be a good shout as well.
I have been speaking to TVR Power about the possibility of using their new MBE ECU to soft start the fans, thus avoiding the voltage drop when they kick in. Upgraded fans that shift more air (CFM in the fan world I believe) would be a good shout as well.
I have had mine N/S rad fan just replaced by Mat Smith, because the old one was very difficult to turn. He was planning on upgrading, but then thought about the old wiring. He thought that the old wiring might not be up to the extra current (amps) that might be drawn because of the uprated fan.
So we went for the standard replacement. I have to say this was of course an improvement anyway over an old tried fan
So maybe check to see if you wiring / fuses are up to the job first?
Just my thoughts of course
So we went for the standard replacement. I have to say this was of course an improvement anyway over an old tried fan
So maybe check to see if you wiring / fuses are up to the job first?
Just my thoughts of course
I'm currently running my suspect O/S fan off my Canems ECU (output one) which allows me to tune the on & off points from my laptop, the second fan and a small electric water pump are run from a traditional otter switch as I wanted them on a permanent live so they run with the key off. The Canems system will allow independent tuning of both fans as there are two outputs offered, but as soon as you switch the engine off you turn the ECU off too so the fans stop just like the daft TVR setup.
My hybrid control system works well, assuming the otter switch rules/values are met the Davies Craig electric booster pump will continue to run giving water circulation even though the mechanical water pump has stopped turning and the N/S fan continues to run pulling cool air through the rad too. So even with the key removed and the car locked the little pump and N/S rad fan will continue to run giving both air flow & water flow (the two things you need to safely lower engine temps) until the off value of the otter switch has been reached.
Essentially the system ensures there is no risk of heat surge when you switch off, lock the car and walk away. With the standard TVR setup everything is immediately shut down when you switch off IE no coolant circulation and no air being pulled through the rad. If you happen to switch the engine off just as the fans cut in you are killing the engine driven water pump and the two fans just when you need both, the coolant temperature inevitably rises dramatically and all that static heat will surge up to the heads with no real flow other than the effects of thermosyphon, this is bad and probably where most head gaskets get cooked.
When I had the standard setup I would always turn the ignition back on and let the fans cycle with the engine off until they stopped as a measure of protection. I have no idea why TVR wired the fans on a switched live from the key but its a daft idea, as we all know every other manufacturer since the dawn of electric rad fans has wired them to continue to run when you switch off. On every other car its extremely common to switch off on a hot day, lock the car and the fans still be whirring away noisily as you walk away, manufacturers wire the rad fans like this for a reason!
Anyway I digress, my staged fan system with permanent live on fan one one & electric booster pump works great but if one of my 20 year old fans is showing signs of getting past its operational life (which it clearly is) it makes perfect sense to me to replace both with something more modern and effective.
I've been looking at the brushless fans from Spal, these were introduced in 2005 and were immediately adopted by Chevrolet for the Corvette model and have been exclusively used by GM that point forward, so these fans are both OEM quality and very well proven.
The key advantages of these more modern brushless fans over the earlier Spal brushed motor fans used on the Chimaera are:
• Higher efficiency yet with lower power consumption
• Lower Noise, vibration and harshness
• Electronic controls with on-board diagnostics
• Motor with integrated electronics
• Battery compensation system
• Proprietary sine-wave sensorless drive
• Low inertia inner rotor design
• Low weight motor
• Higher ambient working temperature
At the end of the day the standard Chimaera fans do their job, but that doesn't mean they cant be improved upon so I think given one of my 20 year old units seems to be blowing relays with annoying regularity it's time to go with a pair of modern Spal brushless motor fans.
Can someone confirm what size I need please?
My hybrid control system works well, assuming the otter switch rules/values are met the Davies Craig electric booster pump will continue to run giving water circulation even though the mechanical water pump has stopped turning and the N/S fan continues to run pulling cool air through the rad too. So even with the key removed and the car locked the little pump and N/S rad fan will continue to run giving both air flow & water flow (the two things you need to safely lower engine temps) until the off value of the otter switch has been reached.
Essentially the system ensures there is no risk of heat surge when you switch off, lock the car and walk away. With the standard TVR setup everything is immediately shut down when you switch off IE no coolant circulation and no air being pulled through the rad. If you happen to switch the engine off just as the fans cut in you are killing the engine driven water pump and the two fans just when you need both, the coolant temperature inevitably rises dramatically and all that static heat will surge up to the heads with no real flow other than the effects of thermosyphon, this is bad and probably where most head gaskets get cooked.
When I had the standard setup I would always turn the ignition back on and let the fans cycle with the engine off until they stopped as a measure of protection. I have no idea why TVR wired the fans on a switched live from the key but its a daft idea, as we all know every other manufacturer since the dawn of electric rad fans has wired them to continue to run when you switch off. On every other car its extremely common to switch off on a hot day, lock the car and the fans still be whirring away noisily as you walk away, manufacturers wire the rad fans like this for a reason!
Anyway I digress, my staged fan system with permanent live on fan one one & electric booster pump works great but if one of my 20 year old fans is showing signs of getting past its operational life (which it clearly is) it makes perfect sense to me to replace both with something more modern and effective.
I've been looking at the brushless fans from Spal, these were introduced in 2005 and were immediately adopted by Chevrolet for the Corvette model and have been exclusively used by GM that point forward, so these fans are both OEM quality and very well proven.
The key advantages of these more modern brushless fans over the earlier Spal brushed motor fans used on the Chimaera are:
• Higher efficiency yet with lower power consumption
• Lower Noise, vibration and harshness
• Electronic controls with on-board diagnostics
• Motor with integrated electronics
• Battery compensation system
• Proprietary sine-wave sensorless drive
• Low inertia inner rotor design
• Low weight motor
• Higher ambient working temperature
At the end of the day the standard Chimaera fans do their job, but that doesn't mean they cant be improved upon so I think given one of my 20 year old units seems to be blowing relays with annoying regularity it's time to go with a pair of modern Spal brushless motor fans.
Can someone confirm what size I need please?
Edited by ChimpOnGas on Friday 13th May 09:36
Ideally you want the fans to be controlled and powered by the ECU so the they can be spun up gradually as the temperature increased, similar to the mod wise kit but much cleaner as you a simplifying the setup to and complicating it but adding extra sensors and controllers.
The question is if the ECU is providing the power to the fans and it is only on when the ignition is on then how do you keep the fans running when the key is removed. I tend to leave the ignition on after stopping the engine as like you say it is still hot and needs cooling, probably not making much difference as the water pump at that stage is not circulating the water.
The question is if the ECU is providing the power to the fans and it is only on when the ignition is on then how do you keep the fans running when the key is removed. I tend to leave the ignition on after stopping the engine as like you say it is still hot and needs cooling, probably not making much difference as the water pump at that stage is not circulating the water.
ChimpOnGas said:
Hi guys,
I'm starting to look at rad fans as my O/S one has been blowing relays and occasionally makes a noticeable and monetary "crack" sound as it chimes in. The "Crack" sound suggests it may be time for replacement and while I haven't put my test meter on the suspect fan yet I suspect when I do I'll see a massive spike when it fires up and that's what's been cooking my relays
Working to my policy of "If I'm replacing, I'm upgrading" I seem to remember Tuscan Spal fans from Powers Performance were being used by some Chimaera owners as they shift quite a bit more air.
Has anyone done this mod, if so is it a straight swap?
I have had to move the expansion tank from the front chassis rail and change the routing of the bottom radiator hose to clear the thicker fan housing and deeper motors plus I decided to use a couple of 70 amp relays (one per fan) as I'm running them "staged"...I'm starting to look at rad fans as my O/S one has been blowing relays and occasionally makes a noticeable and monetary "crack" sound as it chimes in. The "Crack" sound suggests it may be time for replacement and while I haven't put my test meter on the suspect fan yet I suspect when I do I'll see a massive spike when it fires up and that's what's been cooking my relays
Working to my policy of "If I'm replacing, I'm upgrading" I seem to remember Tuscan Spal fans from Powers Performance were being used by some Chimaera owners as they shift quite a bit more air.
Has anyone done this mod, if so is it a straight swap?
Phil
Hoofa said:
Just look at the spall website, I got the biggest flow I could get, also change the inline connectors for some DTM connectors as the old ones can corrode
Yes they are a straight swap
Yes, I forgot I swapped those too ... I used these:Yes they are a straight swap
http://www.ebay.co.uk/itm/141719280389?_trksid=p20...
Phil
Matthew Poxon said:
Ideally you want the fans to be controlled and powered by the ECU so the they can be spun up gradually as the temperature increased, similar to the mod wise kit but much cleaner as you a simplifying the setup to and complicating it but adding extra sensors and controllers.
The question is if the ECU is providing the power to the fans and it is only on when the ignition is on then how do you keep the fans running when the key is removed. I tend to leave the ignition on after stopping the engine as like you say it is still hot and needs cooling, probably not making much difference as the water pump at that stage is not circulating the water.
The soft start function is a nice to have, if the MBE ECU is doing this it's a good feature, but its worth understanding if it'll still run the fans with the ignition key turned off. This is not the case with the Canems system, turn the key off and the fans go off even if the coolant is at 90 degrees or more.The question is if the ECU is providing the power to the fans and it is only on when the ignition is on then how do you keep the fans running when the key is removed. I tend to leave the ignition on after stopping the engine as like you say it is still hot and needs cooling, probably not making much difference as the water pump at that stage is not circulating the water.
I've resolved this with a permanent live on fan one switched by a good old otter switch, fan two remains controlled by the ECU and both are set to be staged in their operation.
Apparently the brushless fans from Spal have their own electronics inside the motors that provide the soft start function which is another reason why they interest me. I plan to keep my switching and electric water pump system just as it is but use a pair of the soft start brushless fans that also shift more air.
Well that's the plan
Edited by ChimpOnGas on Friday 13th May 18:15
Loubaruch said:
Dave,
You mentioned you have a Craig Davis booster pump in circuit. Hope its not in the main cooling path, as if this fails you will get no circulation. Dont ask how I know (on a 1936 Morgan)
Its the Davies Craig electric booster pump (EBP), its really small about the size of a tennis ball and fits in the palm of your hand.You mentioned you have a Craig Davis booster pump in circuit. Hope its not in the main cooling path, as if this fails you will get no circulation. Dont ask how I know (on a 1936 Morgan)
My EBP is plumbed into the heater circuit that's also used to warm my LPG vaporiser, it is not directly plumbed into the main coolant circuit so can not restrict the flow through the block and radiator produced by the original engine driven water pump which remains to do what it does very well indeed. shift a significant volume of coolant.
You'd need a very big electric water pump to shift the volume of coolant a traditional mechanical water pump does, the truth is my little EBP doesn't really shift that much volume, as the name suggests the electric booster pump just boosts the flow of the engine driven pump or offers some light circulation once the engine has stopped turning.
As such the EBP could never be used as a sole water pump on anything other than a go-kart or a small capacity motorcycle, and for these reasons the EBP model from Davies Craig is specificity designed to cause no restriction in flow.
Remember in my system my EBP only chimes in at 88 degrees and goes off at 85 degrees as determined by the otter switch values I chose, so in normal operation it's cycling on and off all the time in unison with fan one. I've run the coolant system like this for many thousands of miles and its never given a hint of trouble, and while testing for the source of relay failure I even ran the car with the power to the EBP disconnected so not running but still plumbed in, for 1,000 miles or more I ran the car like this with no issues whatsoever which proves conclusively the Davies Craig EBP is absolutely no restriction.
The EBP only pulls 1.3amps at most so doesnt require a relay, but still manages to shift 15 Litres a minute which is actually quite impressive for a pump so small, I figured for the 25 seconds or so it will fully circulate the entire contents of the coolant system through the rad while at the same time fan one pulls cool air through the rad.
It certainly works because if you disconnect the EBP and switch of at fan one chimes in the fan will stay on twice as long without the assisted flow with provided by the EBP when connected.
Here's the technical spec...
https://daviescraig.com.au/product/electric-booste...
If you ran your Morgan with one of the Davies Craig bigger electric wter pumps plumbed into the main coolant circuit I can see why it may of offered a restriction if it failed, but my little booster pump in my heater circuit is of no concern to me at all.
Thanks for your input though, and I'm sorry to hear of your issue.
Dave.
Bassfiendnoideawhathp said:
I have had to move the expansion tank from the front chassis rail and change the routing of the bottom radiator hose to clear the thicker fan housing and deeper motors plus I decided to use a couple of 70 amp relays (one per fan) as I'm running them "staged"...
Phil
Do you have a link to, and photos of your 70amp relays Phil?Phil
I assume you needed special relay holders to match as this type of heavy duty relay typically has beefier terminals in my experience.
I've just found the spec from Spal and its quite revealing, Spal says our fans draw 40 amps in normal operation and can spike to 45 amps when they first fire up, this could easily be a higher figure on my fans that have done service for almost 20 years as I'm sure their internal resistance will be higher now than when they were new.
So it seems highly likely my 40 amp relays are right on the edge of their capacity rating, I blew one about 8 months ago which I put down to water ingress as Lloyds mounted them under the bonnet towards the front of the car, so I purchased some natty looking 40amp waterproof relays, these look great but in practice seem like they are internally not really up to the job.
I've now completed an autopsy on both of the two dead waterproof relays that seem to have only lasted a few months each, both exhibit the same failure where the contacts have welded themselves together. At least this type of failure means the fan will just run continuously but as it's on a permanent live it will continue to do so until it flattens the battery.
Once I'd unstuck the welded together contacts it became clear the little leaf spring that holds the them apart is weaker than I'd expect and generally the internal construction of these Chinese made waterproof relays appears to be rather poor.
As an interim measure I've removed these cheap Chinese made waterproof relays and replaced them with what look like better quality regular 40amp diode protected relays purchased from my local Land Rover specialist. Only time will tell if these prove reliable but my gut feeling (given the amp draw & momentary amp spike data from Spal) is that Phil's use of his more suitable rated 70amp relays is a much much safer bet.
Phil, please can you share the details of your 70amp relays mate?
I am in process of install the Motec Pdm module, this is getting rid of relays, however on inspection both my fans are wired from one relay and not one per fan ? , its on a 99 year car
Anyone else got this kind of fan wiring ?
Also no ecu provides a fan soft start function , it's either on or off , depending where you set the temperature on / off points
Anyone else got this kind of fan wiring ?
Also no ecu provides a fan soft start function , it's either on or off , depending where you set the temperature on / off points
Hoofa said:
I am in process of install the Motec Pdm module, this is getting rid of relays, however on inspection both my fans are wired from one relay and not one per fan ? , its on a 99 year car
Anyone else got this kind of fan wiring ?
Also no ecu provides a fan soft start function , it's either on or off , depending where you set the temperature on / off points
That Motec Pdm module looks really clever, I'd be interested to hear how you get on with it.Anyone else got this kind of fan wiring ?
Also no ecu provides a fan soft start function , it's either on or off , depending where you set the temperature on / off points
Hoofa said:
on inspection both my fans are wired from one relay and not one per fan ? , its on a 99 year car
Anyone else got this kind of fan wiring ?
My '94 Griff 500 has only one relay for two fans, the relay has welded itself closed on at least one occasion due to current load. When the fans come on the current draw is so great it almost stalls the engine at tick over. Anyone else got this kind of fan wiring ?
There are some electronic PWM control modules available that provide soft start but they all seem to be USA based products and in the hundreds of $ territory
http://www.spal-usa.com/fans/automated/accessories...
Spal USA seem to have discontinued this, don't know why.
http://derale.com/products/electric-fans/fan-contr...
This one needs a probe stuck into the rad fins which I don't like
http://www.haydenauto.com/Featured%20Products-Digi...
This one is limited to 24amps load, so probably no good for our application.
Has anyone tried these types of devices?
Edited by MisterT on Saturday 14th May 09:45
ChimpOnGas said:
Bassfiendnoideawhathp said:
I have had to move the expansion tank from the front chassis rail and change the routing of the bottom radiator hose to clear the thicker fan housing and deeper motors plus I decided to use a couple of 70 amp relays (one per fan) as I'm running them "staged"...
Phil
Do you have a link to, and photos of your 70amp relays Phil?Phil
ChimpOnGas said:
I assume you needed special relay holders to match as this type of heavy duty relay typically has beefier terminals in my experience.
No - Just wire directly to the base of the relay with crimp terminals - standard spades for the coil and these...http://www.carbuildersolutions.com/uk/yellow-pre-i...
...for the switched feeds.
ChimpOnGas said:
I've just found the spec from Spal and its quite revealing, Spal says our fans draw 40 amps in normal operation and can spike to 45 amps when they first fire up, this could easily be a higher figure on my fans that have done service for almost 20 years as I'm sure their internal resistance will be higher now than when they were new.
Remember that as standard you probably have different fans to me - the very early Chims seemed to have 'pussy spec' SPALs that had a current rating of (IIRC) 9amps each from looking up the specs.The replacement ones I bought were the "one down from top spec" units as the next step up basically doubled the current draw and cost.
Also my early Chim didn't have the cowlings behind the rad either - if I'd just slapped these new units on directly in place of the old ones then I could have got away without moving bits but then that would have negated much of the reason for doing the change anyway. Remember the cowlings don't just help the rad cool better in summer when things are hot by making the fan draw air in over the full area of the radiator but they also help stop the thing overcooling in winter too.
ChimpOnGas said:
So it seems highly likely my 40 amp relays are right on the edge of their capacity rating, I blew one about 8 months ago which I put down to water ingress as Lloyds mounted them under the bonnet towards the front of the car, so I purchased some natty looking 40amp waterproof relays, these look great but in practice seem like they are internally not really up to the job.
One of the reasons I went for two relays was that it gave me the flexibility to trigger the fans separately or together depending on what I wanted to do ... I *COULD* have used 2 x 30 or 2 x 40 amp relays but we've had so many issues with my mates racing Skyline where 40 amp relays have failed permanently closed even when switching loads of less than 40 amps that it just seemed sensible to 'overspec'.As it is I've had a direct 12v feed brought down from the alternator into the nose to a bolt down busbar (initially this was so I could get a good solid feed for the headlights) and fixed the relays to the backs of the cowlings so the high current lines are pretty short. The trigger feeds aren't a problem being as long as necessary as long as they're routed away from the exhausts.
ChimpOnGas said:
I've now completed an autopsy on both of the two dead waterproof relays that seem to have only lasted a few months each, both exhibit the same failure where the contacts have welded themselves together. At least this type of failure means the fan will just run continuously but as it's on a permanent live it will continue to do so until it flattens the battery.
Yup - that was how we found they were failing on the Skyline too ... annoying as hell because some of the failed ones were only switching maybe 10 amps or so and we weren't using cheap no-name eBay stuff.ChimpOnGas said:
Once I'd unstuck the welded together contacts it became clear the little leaf spring that holds the them apart is weaker than I'd expect and generally the internal construction of these Chinese made waterproof relays appears to be rather poor.
TBH although the springs do seem a bit weak that shouldn't really matter - it seems to be that the contacts become "sticky" (which they shouldn't be) and that seems to be the problem on the ones we pulled apart.ChimpOnGas said:
As an interim measure I've removed these cheap Chinese made waterproof relays and replaced them with what look like better quality regular 40amp diode protected relays purchased from my local Land Rover specialist. Only time will tell if these prove reliable but my gut feeling (given the amp draw & momentary amp spike data from Spal) is that Phil's use of his more suitable rated 70amp relays is a much much safer bet.
Phil, please can you share the details of your 70amp relays mate?
Done...Phil, please can you share the details of your 70amp relays mate?
Phil
Hoofa said:
I am in process of install the Motec Pdm module, this is getting rid of relays, however on inspection both my fans are wired from one relay and not one per fan ? , its on a 99 year car
Anyone else got this kind of fan wiring ?
I think that by default they're all single relay ... mine certainly was.Anyone else got this kind of fan wiring ?
Phil
Thanks Phil,
Do keep in mind it's best practice to use a diode protected relay on any ECU driven component like a fan, it's another lesson I've learned along the way
I completed 250 miles today with my new better quality 40amp diode protected relays in place, there must have been literally hundreds of fan cycling events and no issues whatsoever, the solution to my relay burn out frustrations seems to be in the fitment of better quality relays.
Cheers, Dave
Do keep in mind it's best practice to use a diode protected relay on any ECU driven component like a fan, it's another lesson I've learned along the way
I completed 250 miles today with my new better quality 40amp diode protected relays in place, there must have been literally hundreds of fan cycling events and no issues whatsoever, the solution to my relay burn out frustrations seems to be in the fitment of better quality relays.
Cheers, Dave
ChimpOnGas said:
Thanks Phil,
Do keep in mind it's best practice to use a diode protected relay on any ECU driven component like a fan, it's another lesson I've learned along the way
You are quite correct ... however ...Do keep in mind it's best practice to use a diode protected relay on any ECU driven component like a fan, it's another lesson I've learned along the way
1) The relay that came out that had been controlled by the ECU didn't seem to be diode protected.
2) You can diode protect any relay by wiring a diode in reverse across the coil - it's only to kill back EMF.
3) Mine aren't being controlled by the ECU.
ChimpOnGas said:
I completed 250 miles today with my new better quality 40amp diode protected relays in place, there must have been literally hundreds of fan cycling events and no issues whatsoever, the solution to my relay burn out frustrations seems to be in the fitment of better quality relays.
Probably nowhere near "literally hundreds" in reality Dave - I'd be surprised if you even broke into triple digits TBH but you'll get an idea from the logging on the CANEMS software if you actually want to know for sure - and it is only one day too!How long were your other relays in and working before they started sticking? I hope to God it was more than a few days!!!
We were using what should have been quality relays on the Skyline (and yes, they were diode protected) driven from a SYVECS ECU but they still failed - basically anything with a comparatively high starting (inrush / making) current and a high operating (breaking) current will beat the living crap out of relay contacts due to arcing as they make and break and cause them to become pitted. That pitting reduces the contact area (and can also make the contacts stick) so increases the current per sqmm of contact which can make the contact faces run increasingly hotter ... relays have a switching current rating as well as a continuous current handling rating but it's the switching current rating that is normally not listed by sellers / retailers...
I will usually try to get hold of Omron relays if I can because they seem well built. See: https://www.omron.com/ecb/products/search/?cat=1&a...
Cheers
Phil
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