viability of electric water pumps
#101
it is my understanding that in reference to temperature only Evans does run hotter than other engine coolants. It has less heat carring capacity. But, there is more to it than that.
Evans prevents run a way temps. No local vapor will occur. The Evans will always be removing heat no matter what the engines temps are. This is unlike normal type cooling in which at a certain temp the coolant will start to have a localized vapor which will prevent much heat exchange between the metal and coolant.
Evans also doesnt require any pressure in the system to work. This can be advantageous in some cases or of no concern in others. Thats my laymans understanding of it anyway.
Actually increasing the engine normal operating temperture ( and its ability to tolerate) will make the engine more efficent.
Like all other stuff--its a balance and there are limits. I have heard of recip engines at the track that run Evans ( when rules allow) having a coolant temp of 250-260F! Insane! Of course they are also using synthetic oil
I understand that when using Evans in our car a coolant tempt of 210-220F is quite normal.
I am thiking of converting myself.
Fan control ( both on at the same time--slow or fast) + EWP with computer control ( no bypass, no thermostat) is the best system i can think off. Even BMW has a secondary EWP for these type of situations.
My exhaust in slow traffic on a 104F day got the o2 sensor so hot--it wasnt working right. True story.
Evans prevents run a way temps. No local vapor will occur. The Evans will always be removing heat no matter what the engines temps are. This is unlike normal type cooling in which at a certain temp the coolant will start to have a localized vapor which will prevent much heat exchange between the metal and coolant.
Evans also doesnt require any pressure in the system to work. This can be advantageous in some cases or of no concern in others. Thats my laymans understanding of it anyway.
Actually increasing the engine normal operating temperture ( and its ability to tolerate) will make the engine more efficent.
Like all other stuff--its a balance and there are limits. I have heard of recip engines at the track that run Evans ( when rules allow) having a coolant temp of 250-260F! Insane! Of course they are also using synthetic oil
I understand that when using Evans in our car a coolant tempt of 210-220F is quite normal.
I am thiking of converting myself.
Fan control ( both on at the same time--slow or fast) + EWP with computer control ( no bypass, no thermostat) is the best system i can think off. Even BMW has a secondary EWP for these type of situations.
My exhaust in slow traffic on a 104F day got the o2 sensor so hot--it wasnt working right. True story.
Last edited by olddragger; 03-20-2012 at 09:04 AM.
#102
Evans prevents run a way temps. No local vapor will occur. The Evans will always be removing heat no matter what the engines temps are. This is unlike normal type cooling in which at a certain temp the coolant will start to have a localized vapor which will prevent much heat exchange between the metal and coolant.
Lets take it even further, there has been research adiabatic rotary engine, no coolant at all, efficiency went up maybe by 1% and most of the heat that would normally go to the coolant went into the exhaust, do you really want even higher EGT's?
#104
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Does Evans run hotter in general? 118°c just for daily driving with the A\C seems absurd. If that fluid doesn't play a role i would check for other issues in the car.
Opening the oil cooler vents and an open front grille instead of our fake one should be enough to keep the car cool even during a traffic jam.
The only cars i saw run that hot all had other problems (catalytic converter, poor maintenance\compression etc).
Opening the oil cooler vents and an open front grille instead of our fake one should be enough to keep the car cool even during a traffic jam.
The only cars i saw run that hot all had other problems (catalytic converter, poor maintenance\compression etc).
To answer your question, I observed that Evans NPG+ generally runs about 3C (5F) warmer than water-based coolant due to it being more viscous than water-based coolants; but nothing like what I saw that day. I do not know, at this point, whether the problem is:
1. inadequate coolant flow at low engine speeds (3K and lower)
2. insufficient air flow at low chassis speeds
3. 1&2 combined
I intend to open the oil cooler vents shortly (got a lovely Dremel for Christmas) and relocate the front plate to low on the left side (quasi-EVO style) to clear airway for the radiator.
As a matter of last resort, I am also considering switching to an AEM intake and relocating the battery out of the engine bay in order free up air flow behind the radiator.
#105
Modulated Moderator
iTrader: (3)
As a FYI....I haven't seen ANY elevated temps with the Evans coolant at all. The temp is very stable at the thermostat opening temp...and basically doesn't change at all with load. I found that the temp will vary with different thermostats ...I have one that is 3 degrees cooler than the other...both OEM
The electric water pump works well....I have it hooked to my turbo timer so it will run for a period of time after I shut the car off...
The electric water pump works well....I have it hooked to my turbo timer so it will run for a period of time after I shut the car off...
#106
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I don't want to get into bashing anyone's merchandise, but IMO there are a lot of products on this forum that are excessively overhyped and overplayed that do little to nothing as compared to the all the advice members here dish out over them.
#107
the extended rpm range of a rotary engine makes this very difficult to achieve i.e proper flow at idle vs max rpm. Simply tying in a mechanical pump to operate based on a linear RPM scalar alone won't and can't address this. The demands of the system are not linear. An electric water pump let's you have your cake and eat it too. A properly designed electric pump is no less prone to failure than any other mechanical device. Pump seals fail, belts break, bearings wear out. It all happens eventually. Who has a mechanical fuel pump any more?
I don't want to get into bashing anyone's merchandise, but IMO there are a lot of products on this forum that are excessively overhyped and overplayed that do little to nothing as compared to the all the advice members here dish out over them.
I don't want to get into bashing anyone's merchandise, but IMO there are a lot of products on this forum that are excessively overhyped and overplayed that do little to nothing as compared to the all the advice members here dish out over them.
Talking about "anyone's merchandise", Mazmart's water pump is not one of the products you mention. I have been running that water pump for years now and the temperatures are more stable, especially when running at high rpms.
To sum my opinion up: An electric water pump is a cool gizmo that is useless on a street car with basic cooling mods and may be interesting for a track setup. May or may not actually, depending on the real cooling needs.
#109
Your experience vs my beliefs? How about your experience vs mine? Running in parking lots doesn't make you the keeper of the absolute truth just like road racing doesn't do that for me.
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revchux (12-13-2023)
#110
Momentum Keeps Me Going
#111
I believe dan is running the davis craig pump? I may be wrong?
So Dan--you continued to run a thermostat? I was thinking that one of the benefits of the ewp was the ability to not run a thermostat?
Guys this is just another option, depending on what your particular needs are. I do think it has lots of benefits over the mechanical--mainly increased flow in the lower rpms and its ability to prevent shutdown boilover. Team nailed it in saying we have a huge rpm band and no mechanical pump can be expected to be perfect under those conditions.
A coolant system is dependant on flow. Both the coolant and the air over the radiator. Its not a simple system. Our current system is a combination of mechanical valves, bypass channels, pump and electronic fan controls. They are all interrelated and have overlapping responsibility. The EWP/controller can simplify the system a little in that you would no longer need the by pass or the thermostat. Quicker warm ups, less temperature functuations in traffic ( fans on and off), better cool down on shut off are benefits also that come to mind.
One other thing I have read about is high rpm mechanical pump cavitation due to the lost of coolant viscosity. This is something that Evans coolant research papers speak off. It seems to me that the EWP would be less likely to experience this as it's rpms are not as high as the mechanical when the engine is at high rpm.
Its time for me to explore this a little further--me thinks.
So Dan--you continued to run a thermostat? I was thinking that one of the benefits of the ewp was the ability to not run a thermostat?
Guys this is just another option, depending on what your particular needs are. I do think it has lots of benefits over the mechanical--mainly increased flow in the lower rpms and its ability to prevent shutdown boilover. Team nailed it in saying we have a huge rpm band and no mechanical pump can be expected to be perfect under those conditions.
A coolant system is dependant on flow. Both the coolant and the air over the radiator. Its not a simple system. Our current system is a combination of mechanical valves, bypass channels, pump and electronic fan controls. They are all interrelated and have overlapping responsibility. The EWP/controller can simplify the system a little in that you would no longer need the by pass or the thermostat. Quicker warm ups, less temperature functuations in traffic ( fans on and off), better cool down on shut off are benefits also that come to mind.
One other thing I have read about is high rpm mechanical pump cavitation due to the lost of coolant viscosity. This is something that Evans coolant research papers speak off. It seems to me that the EWP would be less likely to experience this as it's rpms are not as high as the mechanical when the engine is at high rpm.
Its time for me to explore this a little further--me thinks.
#112
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A cool gizmo an EWP would be yes but not useless, even if the gain is only like 1 HP more or 1 MPG more, it would benefit itself, on top of other mentioned advantages..
http://www.daviescraig.com.au/Electr...5-details.aspx
And this Davies and Craig water pump seems to be my choice when I do this swap, but really around 21.13333 GPM that pump can push can be beat by a Meziere more expensive pump.. But around $200 for that cool Turbo looking D&C pump and another $200 for the plate is not "Too expensive" of a mod that will eventually pay itself off with gas mileage..
http://www.daviescraig.com.au/Electr...5-details.aspx
And this Davies and Craig water pump seems to be my choice when I do this swap, but really around 21.13333 GPM that pump can push can be beat by a Meziere more expensive pump.. But around $200 for that cool Turbo looking D&C pump and another $200 for the plate is not "Too expensive" of a mod that will eventually pay itself off with gas mileage..
Last edited by VICEdOUT; 03-21-2012 at 09:26 AM.
#115
Yes, somewhere I must find it.
Generally, at sea level and low altitudes, higher water jacket temperature does decrease friction horsepower and of course promotes fuel evaporation which is good for overall efficiency, but it also hurts volumetric efficiency so the net BHP is lower.
Decrease in friction horsepower is dependent on lubricant properties itself and in the end of the day, we are talking about magnitude around 1% with 50°C delta, so friction change can be neglected.
Only what remains is VE and fuel evaporation. Cooler engine will ingest more air mass so this is straightforward. And fuel evaporation can be optimized by higher fuel temperature and injection pressure.
Here are some references discussing same subject http://not2fast.com/NACA/naca-tn-476.pdf
http://www.scribd.com/doc/40610101/T...-Harry-Ricardo Chapter III, DISTRIBUTION OF HEAT IN A HIGH-SPEED FOUR-CYCLE ENGINE
Generally, at sea level and low altitudes, higher water jacket temperature does decrease friction horsepower and of course promotes fuel evaporation which is good for overall efficiency, but it also hurts volumetric efficiency so the net BHP is lower.
Decrease in friction horsepower is dependent on lubricant properties itself and in the end of the day, we are talking about magnitude around 1% with 50°C delta, so friction change can be neglected.
Only what remains is VE and fuel evaporation. Cooler engine will ingest more air mass so this is straightforward. And fuel evaporation can be optimized by higher fuel temperature and injection pressure.
Here are some references discussing same subject http://not2fast.com/NACA/naca-tn-476.pdf
http://www.scribd.com/doc/40610101/T...-Harry-Ricardo Chapter III, DISTRIBUTION OF HEAT IN A HIGH-SPEED FOUR-CYCLE ENGINE
#116
Momentum Keeps Me Going
I'd appreciate hearing from Dan about some of his experiences like...
- any pic of how/where you have mounted the pump?
- is your application replacing or adding to the mechanical?
- what temp control to you use, if any, of the suggested choices?
- did you do any before/after HP measurments esp. at high RPM as Craig mentions?
- any subjective comments before/after?
- ease of install/setup/use?
Thanx
- any pic of how/where you have mounted the pump?
- is your application replacing or adding to the mechanical?
- what temp control to you use, if any, of the suggested choices?
- did you do any before/after HP measurments esp. at high RPM as Craig mentions?
- any subjective comments before/after?
- ease of install/setup/use?
Thanx
#117
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iTrader: (1)
As a FYI....I haven't seen ANY elevated temps with the Evans coolant at all. The temp is very stable at the thermostat opening temp...and basically doesn't change at all with load. I found that the temp will vary with different thermostats ...I have one that is 3 degrees cooler than the other...both OEM
The electric water pump works well....I have it hooked to my turbo timer so it will run for a period of time after I shut the car off...
The electric water pump works well....I have it hooked to my turbo timer so it will run for a period of time after I shut the car off...
Also, which Evans coolant are you using, NPG, NPG+, or NPGR? I'm using NPG+, at the recommendation of Evans; but I am thinking about switching to NPGR because of its lower viscosity.
Last edited by longpath; 03-21-2012 at 03:42 PM. Reason: I'm a crummy typist and a worse proofreader.
#118
Modulated Moderator
iTrader: (3)
I'd appreciate hearing from Dan about some of his experiences like...
- any pic of how/where you have mounted the pump? I will look...I have a few. I mounted it under the frame horn in the passenger side beside the oil cooler. Depending on what you have installed and what pump you will have to find a place for it to fit
- is your application replacing or adding to the mechanical? I removed the OEM mechanical pump and fitted a block-off plate that has fittings for the pump inlet and outlet
- what temp control to you use, if any, of the suggested choices? OEM thermostat Can't justify any more complexity for an electric controller
- did you do any before/after HP measurements esp. at high RPM as Craig mentions? No...don't really care I guess...looking for better cooling..and the benefit of being able to shut down the engine and circulate the coolant..as well as the increased flow
- any subjective comments before/after?
- ease of install/setup/use?
I like the way it works..It was relatively easy to install. I worked with Scott at RX-8 Performance on the bits...so he has the plate for sale...and can help you choose a pump and mounting location. I used the air pump relay as it was close to where I mounted the pump and unused and a big relay..that was easy and triggered it off the ignition wire so that when the key was on to "go" the pump will run.
I will have more information soon....but I'm not sure how relevant it will be to a stock setup because there is nothing stock left really I can monitor temps both with the stock ECT sensor..and an aftermarket PLX sensor so very accurately
Thanx
- any pic of how/where you have mounted the pump? I will look...I have a few. I mounted it under the frame horn in the passenger side beside the oil cooler. Depending on what you have installed and what pump you will have to find a place for it to fit
- is your application replacing or adding to the mechanical? I removed the OEM mechanical pump and fitted a block-off plate that has fittings for the pump inlet and outlet
- what temp control to you use, if any, of the suggested choices? OEM thermostat Can't justify any more complexity for an electric controller
- did you do any before/after HP measurements esp. at high RPM as Craig mentions? No...don't really care I guess...looking for better cooling..and the benefit of being able to shut down the engine and circulate the coolant..as well as the increased flow
- any subjective comments before/after?
- ease of install/setup/use?
I like the way it works..It was relatively easy to install. I worked with Scott at RX-8 Performance on the bits...so he has the plate for sale...and can help you choose a pump and mounting location. I used the air pump relay as it was close to where I mounted the pump and unused and a big relay..that was easy and triggered it off the ignition wire so that when the key was on to "go" the pump will run.
I will have more information soon....but I'm not sure how relevant it will be to a stock setup because there is nothing stock left really I can monitor temps both with the stock ECT sensor..and an aftermarket PLX sensor so very accurately
Thanx
Also...was using NPG-R...but will be going to NPC+C next week...as they have discontinued the other 2 racing coolants for just this one
#119
thanks Dan. Good info. So running with a thermostat and by pass intact +Evans. Sweet---simple and efficient obviously.
Have yall seen the mezerine single intake double output remote mount pump?
http://www.meziere.com/ps-1150-1118-wp337s.aspx
Have yall seen the mezerine single intake double output remote mount pump?
http://www.meziere.com/ps-1150-1118-wp337s.aspx
#120
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Got my EWP Plate in... (Thank you Scott) from http://www.rx8performance.com/produc...ric-water-pump
I'll post more pictures of the EWP on this thread when I get the water pump itself and hoses and finally mount it in the STARX8.
For updates on MY custom build, click on the link below and follow the progress on my Picasa Web Album. =D
I'll post more pictures of the EWP on this thread when I get the water pump itself and hoses and finally mount it in the STARX8.
For updates on MY custom build, click on the link below and follow the progress on my Picasa Web Album. =D
Last edited by VICEdOUT; 04-13-2012 at 10:48 AM.
#121
FULLY SEMI AUTOMATIC
iTrader: (9)
i was wondering what happened to that build. update
#124
very nice--using the merizne pump? One hint--- use a restrictor in the heater hose.
You will not be running the coolant bypass---right? The thermostat housing can be modified to accept a GM barrel type thermostat which will allow increase flow at a lower head pressure.
You will not be running the coolant bypass---right? The thermostat housing can be modified to accept a GM barrel type thermostat which will allow increase flow at a lower head pressure.