280zex Posted June 19, 2015 Share Posted June 19, 2015 (edited) I did find an old post about the CSR electric water pump here : http://forums.hybridz.org/topic/43305-csr-water-pump/ Just wondering who else runs an electric pump setup?? My reasons why I am looking into going electric. 1- an attempt to control heat spike cycling, and reduce head gasket wear. 2- free up wasted HP I have also seen a setup around HBZ that a guy made a bracket and used an electric motor to turn the stock water pump. Right now I am researching water flow values for the stock nissan water pump. I ASSUME ABOUT 33 TO 36GPH?? The stand alone water pump from MSA: http://www.thezstore.com/page/TZS/PROD/16-7025 I like this unit and coupled with a Davies electronic control unit it should work with what I am planning.. My current setup: Turbo charged L28, ebay 3 row aluminum radiator, 1982 turbo water pump, custom heater core (all in 1 unit for a jeep). I do not use the thermostat bypass hose setup as my heater core is free flowing I.E. it has no off valves. It flows from off the back of the head, thru the dash core, and then back to the water pump. 190F thermostat. My Z has a thermal cycle from 190F to about 220 if I'm driving hard, and 190F to 205F on cruze. The temp guage shows a lot of thermal temp cycling unless its 85F+ outside, then it stays about 200F solid. I am concerned about all that thermal cycling and premature head gasket failure. My hope is that I may be able to control that thermal cycle better with a stand alone electric water pump and control system... Edited June 19, 2015 by 280zex Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted June 20, 2015 Share Posted June 20, 2015 From my experience you have a problem you need to sort out before throwing any modifications at the system.When I had my turbo L28, in my '73, it would run a solid 182*F +/- about 2* during cruise even on the hottest of summer days, with a 180* stat. Flogging on it, I wouldn't get over 190 +/- 2*, and that took a LOT of flogging to get that high. Stock heater core, oil cooled turbo (no coolant provisions), 280Z rad, 15 PSI cap, though towards the end it was a bit weak.If I were in your shoes, I'd look at the condition of the coolant, make sure that the T-stat is good, because it sounds like it might be a bit lazy, that the coolant level is correct and that there are no bubbles in the coolant, and make sure that there is sufficient bypass happening. Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 20, 2015 Share Posted June 20, 2015 The thermostat does look suspect. I had an old thermostat and it would do the same, even though it looked fine when tested in a pan of hot water on the stove. No flow there though. It allowed a wide range of temperature, about 170 to 190, and moved up and down with engine use and daily temperature. Bought a new Nissan brand 180 degree unit and it's very steady now, hits the number quickly (actually about 185) and sits there. Might rise 5 degrees on a hot day after some use. Using an inexpensive parts store Murray brand radiator. Stock NA engine. Quote Link to comment Share on other sites More sharing options...
280zex Posted June 20, 2015 Author Share Posted June 20, 2015 Every single part in question is brand new, with less than 6k miles. I can pull the t-stat and test it. I remove the water pump belt when flushing my coolant so i can spin it by hand. This can possibly help remove any air bubbles. I am assuming that the new aluminum radiator is really good at removing heat. My Z runs a perfect 200f as long as the ambiant temp is atleast 80f, any colder and the temp guage shows a lot of thermal cycling. the system may possibly have an air bubble stuck some place..... My turbo is oil cooled, so that is not an issue, or is it?? i have a 1.1 bar radiator cap. i use sierra premix coolant with 1 bottle of wetter water. i use an 14 inch electric puller fan on the passenger side of the radiator. Quote Link to comment Share on other sites More sharing options...
280zex Posted June 20, 2015 Author Share Posted June 20, 2015 Here are some pix of my current coolant system. I dont have the t-stat bypass hose installed. From the reading here on HBZ I assume that I didnt need the t-stat bypass due to my heater core has no shut off valve like the stock factory system. I assume that this is not an issue?? maybe it is?? I get heat out from the core with-in 1 minute of start-up from being cold. I will go buy another factory Nissan t-stat and install that later today just to see what happens. I can also install that small t-stat bypass hose just to see if that helps equalize the temps better. I will also get some new coolant and flush the system. I did the vinegar block flushing trick when I rebuilt the engine. I will look into finding a way to completely flush the coolant system with the t-stat removed, just to see what may be cleaned out.... Quote Link to comment Share on other sites More sharing options...
TimZ Posted June 20, 2015 Share Posted June 20, 2015 (edited) Every single part in question is brand new, with less than 6k miles. I can pull the t-stat and test it. I remove the water pump belt when flushing my coolant so i can spin it by hand. This can possibly help remove any air bubbles. I am assuming that the new aluminum radiator is really good at removing heat. My Z runs a perfect 200f as long as the ambiant temp is atleast 80f, any colder and the temp guage shows a lot of thermal cycling. the system may possibly have an air bubble stuck some place..... My turbo is oil cooled, so that is not an issue, or is it?? i have a 1.1 bar radiator cap. i use sierra premix coolant with 1 bottle of wetter water. i use an 14 inch electric puller fan on the passenger side of the radiator. Any idea what your EGTs look like at cruise and idle? I was fighting very similar issues for years - I had large injectors and could only go so lean at idle before the injectors went unstable, and was controlling idle speed by letting more air in via the bypass screws to get a suitably lean mix, and then controlling speed with ignition advance (retard actually). This generally put my idle EGTs (measured at the turbine inlet) up around 1200 degF. I never thought that much of it since I figured I had everything ceramic coated (combustion chambers, exhuast ports, exhaust manifold, etc) and pretty well heat shielded to boot. 1200 degF was kind of high but I figured that was happening after the combustion chamber anyway so didn't think it would have much effect on coolant temps. This turned out to be wrong. When I went to staged injectors I was able to get much more stable lean mixtures at idle. First thing I noticed was that my EGTs dropped sharply when I leaned the idle mix, which was a bit counter-intuitive. I ended up leaning the crap out of my idle mix and running a lot more advance. EGTs dropped to ~800 degF and my coolant temps at idle stopped climbing above the set-point. I then (CAREFULLY) remapped my advance and fuel curves at cruise to lower EGTs at there as well. I can now run my AC on a hot night pretty much indefinitely without coolant temp issues. Oh - almost forgot... I ran the CSR electric pump for a while, and aside from the nice feature of controlling heat soak by running for a while after the engine was shut off, it did not help my coolant temp issues. At all. As I recall it would be okay for a while and then just go into thermal runaway and I'd have to shut it down and let it run for a while with the engine off to cool things back down. I even tried using a thermostatic switch - controlled Kenne Bell Boost-a-Pump to speed it up if the temps climbed to no avail. I'm currently running a diesel mechanical pump and stock mechanical fan and NPG-R coolant. I don't think it's having a significant effect on my power production. Edited June 20, 2015 by TimZ Quote Link to comment Share on other sites More sharing options...
280zex Posted June 20, 2015 Author Share Posted June 20, 2015 I dont have an EGT sensor, I will look into that. I did re-tune my ignition timing map last weekend on the dyno. I was able to pull a lot of fuel from the idle circuit. FYI-my turbo system is a blow thru Holley carb not EFI... Quote Link to comment Share on other sites More sharing options...
280zex Posted June 20, 2015 Author Share Posted June 20, 2015 I think I will go shoot some video, just so people can get a better idea of what I am seeing. It may come down to the fact that I am being to hyper-sensitive to what may be a good working coolant system???? Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 20, 2015 Share Posted June 20, 2015 I do not use the thermostat bypass hose setup as my heater core is free flowing I.E. it has no off valves. It flows from off the back of the head, thru the dash core, and then back It's been documented that too much flow from the back of the head back to the pump inlet (the typical bypass that people do when they get a leak in the cabin) reduces overall cooling capacity. It reduces flow through the head and thermostat and back to the radiator. A short circuit, effectively reducing pump output. You might try clamping your heater core line closed and seeing what happens. Maybe your new core flows more than the stock system. If it has an effect, you can restrict flow through the core to improve cooling but still have heat. Quote Link to comment Share on other sites More sharing options...
280zex Posted June 20, 2015 Author Share Posted June 20, 2015 It's been documented that too much flow from the back of the head back to the pump inlet (the typical bypass that people do when they get a leak in the cabin) reduces overall cooling capacity. It reduces flow through the head and thermostat and back to the radiator. A short circuit, effectively reducing pump output. You might try clamping your heater core line closed and seeing what happens. Maybe your new core flows more than the stock system. If it has an effect, you can restrict flow through the core to improve cooling but still have heat. Now that is something I didnt take into consideration. I can go do some testing. I took the car for a drive and its warm enough outside that i only seen a 8F deg fluctuation on the temp gauge today. Oddly enough I only see ugly thermal spikes when its below 80F. I live in Washington and most of the year it satys below 70F, and thats when my Z coolant temp has a nasty thermal spike, or so says the autometer coolant temp gauge. Quote Link to comment Share on other sites More sharing options...
johnc Posted June 21, 2015 Share Posted June 21, 2015 I think NewZed nailed it. Quote Link to comment Share on other sites More sharing options...
280zex Posted June 21, 2015 Author Share Posted June 21, 2015 Ok here is the plan: 1-Drain coolant and replace the thermostat and new coolant. 2-if new t-stat doent help then i can install a ball valve inline with the heater core. 3-if not the heater core then i will install the small t-stat bypass line. Right now step 1 is done and today its test drive time. I hope it was just a bad t-stat... Quote Link to comment Share on other sites More sharing options...
280zex Posted June 24, 2015 Author Share Posted June 24, 2015 T-stat bypass hose fixed my issue, or maybe there was an air bubble traped some where inside the cooling system. Either way i still plan on installing an electric water pump setup. After run shut down temps spike to 230f behind the t-stat, even with the after run fans on... Quote Link to comment Share on other sites More sharing options...
roger280zx Posted June 24, 2015 Share Posted June 24, 2015 What are your oil temps? Do you run a cooler? These cars are very responsive to adding an oil cooler I have seen it fix the problems that a $2000 radiator/shroud/fan couldn't fix. Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 24, 2015 Share Posted June 24, 2015 Ok here is the plan: 1-Drain coolant and replace the thermostat and new coolant. 2-if new t-stat doent help then i can install a ball valve inline with the heater core. 3-if not the heater core then i will install the small t-stat bypass line. Right now step 1 is done and today its test drive time. I hope it was just a bad t-stat... For the record - you did these three things in order, and confirmed the problem still existed for #1 and #2. But it went away when you did #3? I'm kind of nerdy and like the scientific approach. Just wondering. Quote Link to comment Share on other sites More sharing options...
280zex Posted June 24, 2015 Author Share Posted June 24, 2015 What are your oil temps? Do you run a cooler? These cars are very responsive to adding an oil cooler I have seen it fix the problems that a $2000 radiator/shroud/fan couldn't fix. Yes i have a 12x12 inch oil cooler, mounted in front of the car... Quote Link to comment Share on other sites More sharing options...
280zex Posted June 24, 2015 Author Share Posted June 24, 2015 For the record - you did these three things in order, and confirmed the problem still existed for #1 and #2. But it went away when you did #3? I'm kind of nerdy and like the scientific approach. Just wondering. No. If you dont have coolant flow thru your heater core, a t-stat bypass line is a must have. Basicly a t-stat bypass line is just a good idea. My Z never had one from when i got it from the wrecking yard. I never had any cooling issues until i installed the blow thru turbo setup. My Z will stay 202f temp IF im going 100+mph, OR if it is hotter than 80f outside air temp. The coolant temps usualy swings between 190f and 210-215f if im just cruzing down the road, and its a very active fluctuation. I installed an inline ball valve to the heater core and shut that off, its summer time and i dont use it. I then installed a t-stat bypass line in 3/8inch diameter from off the bottom of the t-stat housing to a T fitting at the water pump/heater core coolant junction. I used some ugly fittings and fuel line just for the testing. Quote Link to comment Share on other sites More sharing options...
280zex Posted June 24, 2015 Author Share Posted June 24, 2015 To note: i am still going to install an electric pump and control system to help remove after run coolant temp spikes. Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 24, 2015 Share Posted June 24, 2015 Thanks. Still not clear what caused the temperature instability to go away (or what caused it in the first place). So you did everything at once, or did 1 first, then 2 and 3 at the same time? And the line from the water pump inlet that comes from the thermostat housing would just allow flow through the pump when the thermostat is closed. Not seeing that correlation. Probably insignificant in stock form but it actually is another short circuit for the pump, but a little different. A loop of coolant that doesn't pass through the radiator. So it cools the engine and head but doesn't get cooled itself. Anyway, it was an interesting problem. If you get a chance and want to add to the body of knowledge you might open up that ball valve and report what happens. Quote Link to comment Share on other sites More sharing options...
280zex Posted June 25, 2015 Author Share Posted June 25, 2015 I did step 1 first. New coolant, new t-stat. Had same wierd temp spike. I then installed the t-stat bypass line and closed off the heater core line. No more wierd temp spikes. There is a topic around here i found about the importance of having that t-stat bypass line installed, and the size of the line too. Quote Link to comment Share on other sites More sharing options...
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