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Thread: Remote Electric Water Pump

  1. #1
    Member gongloo's Avatar
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    Remote Electric Water Pump

    I'm thinking of replacing my water pump with a remote electric unit mounted somewhere towards the front of the car, and then running AN lines though much the cooling system (with custom flanges/fittings wherever needed). Some of the reasons I think this might be cool (pun intended):

    1. Frees up space in the engine compartment, making the VoD easier to access, clean, and investigate.
    2. Reduces rear weight bias a tiny bit (every pound counts!).
    3. Eliminates long heater return line from front to back of car (reducing front-to-rear coolant lines from four to three).
    4. Puts otterstat in return line from radiator rather than feed line to radiator, possibly reducing unnecessary fan activity.
    5. Allows the water pump to be configured to run only when the engine is above a certain temperature, decreasing warm-up time to optimal temperature.
    6. Allows the water pump to be configured to run for some time after the engine has shut off.
    7. Eliminates failure mode of engine overheating with a shredded/malfunctioning belt.
    8. Reduces unnecessary engine load at high RPM (I doubt this would be noticeable, but every horse counts!).
    9. Makes water pump and/or thermostat replacement trivial later down the line.
    10. AN fittings eliminate leaky hose connections and greatly reduce maintenance pain.

    I created this crude diagram to help get straight all of the routing. This moves the thermostat, otterstat and water pump out of the engine compartment and close to the radiator. Though I haven't yet looked at exact options for mounting locations, I suspect I can find a place up front that's accessible with reasonable ease from under the car.



    Would love to hear your thoughts, especially if anyone has made significant modifications to the cooling system like this before. Right now this is mostly a thought experiment, but if I decide to pursue this further, I'll document any progress made here.

  2. #2
    Guy with a DeLorean Mark D's Avatar
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    I can understand where you are coming from wanting to improve the car and make it more modern, add some control functionality, etc.

    But unless you plan on keeping this car forever, it sounds to me like this is something that would need to document to the Nth degree to avoid being the 'dreaded previous owner' if you ever sell your car later on down the line. What may seem like an improvement now will most likely be something that the next owner will have to un-do to return the car back to stock. It may also devalue your car if potential buyers do not want to deal with a custom setup that nobody else knows how to troubleshoot or repair without remaking custom hoses, buying special AN fittings, etc.

    Is the standard cooling system design really that bad that it needs to be completely re-engineered? There are a few obvious shortcomings like dealing with broken bolts on the Y pipe in the VOD, the plastic overflow bottle that typically gets updated to stainless, and the plastic side tanks on the radiator. But for the most part it's a well designed system that is very robust compared to a lot of modern cars. Nearly all of the shortcomings can be addressed with a one-time replacement of a part like the expansion tank / radiator / etc. I'm not reading dozens of threads on DMCTalk about ongoing cooling system issues that would benefit from completely redesigning the system.

    The cooling system was 100% original on my DeLorean until around 2011 when as a preventative measure I replaced a bunch of stuff, you know, just because I was in there doing other stuff. The system lasted decades before any major parts needed replacement...Compare that to my daily driver, A 2004 E46 BMW 325i. This car has a cooling system that is nearly all plastic and has a recommended service life of 60,000 miles or 5 years. There are pages upon pages of DIY threads and guides for how to "refresh" the cooling system before a catastrophic failure occurs. The expansion tank loves to crack and eventually explode, ejecting all the coolant from the engine which leads to nearly instantaneous overheat -> cylinder head warping -> head gasket failure -> engine failure. This is obviously an extreme comparison, but it makes the DeLorean cooling system with it's aluminum tubes and rubber hoses look like a bulletproof system.

    If you do go ahead with your redesign I would suggest that you at least make it easily reversible just in case you (or a future owner) decide to go back to the stock configuration. It does sound like a really cool project to watch and see how it's all going to work out. If this is something that you're really passionate about doing don't let me or anyone else kill your ambition.
    Last edited by Mark D; 06-27-2019 at 09:01 AM.
    Mark Dehlinger

  3. #3
    EFI'd dn010's Avatar
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    Few things:

    You will still need a belt to run the alternator so you'd need to figure that part out as well. Might be simple as getting a smaller belt for just the crank to alternator unless the angle of the tensioner doesn't allow it to work.

    You'd probably want coolant to circulate when the engine is running so that you don't get hot spots in the engine and all sensors get the same temp coolant.

    You'd probably not want to run the pump when the engine is off unless you also plan to have it run cooling fans at the same time [battery strain].

    How often do you plan to access your VOD for maintenance that justifies removing the pump and redesigning the cooling system?

    Just a preference, but I would rather have a mechanical pump that slowly indicates it's need for replacement [by weeping] over an electric pump that either works, or it doesn't, and usually the doesn't part comes at the worst times.

    I'm not going to get into the whole weight reduction of removing a water pump or your HP gain. If that is a concern of yours you should probably be checking out engine swaps instead.

    I can see the benefits you're trying to achieve, but personally the water pump is the LAST thing I worry about when I am driving. 17 years later and I haven't had a blown hose or coolant related breakdown, knock on wood. If you do go forward with the project, you'd certainly be the first one to do so! Good luck.
    -----Dan B.

  4. #4
    '82 T3 FABombjoy's Avatar
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    I would take all that money you're going to spend on AN fittings, hoses, electric pump, wiring, etc., and put it toward EFI instead:

    Quote Originally Posted by gongloo View Post
    1. Frees up space in the engine compartment, making the VoD easier to access, clean, and investigate.
    4. Puts otterstat in return line from radiator rather than feed line to radiator, possibly reducing unnecessary fan activity.
    5. Allows the water pump to be configured to run only when the engine is above a certain temperature, decreasing warm-up time to optimal temperature.
    6. Allows the water pump to be configured to run for some time after the engine has shut off.
    9. Makes water pump and/or thermostat replacement trivial later down the line.
    #1: VOD access in 10 minutes on a well set up EFI system, even with the original intake.
    All of the other could be computer controlled
    #5 might create hotspots around the liners and I wouldn't do it
    #6 would just put you back in to warm-up mode faster and decrease efficiency. You want the engine up to temp as quickly as possible.

    Quote Originally Posted by gongloo View Post
    3. Eliminates long heater return line from front to back of car (reducing front-to-rear coolant lines from four to three).
    It's aluminum tube and can't weigh more than a few pounds.

    Quote Originally Posted by gongloo View Post
    7. Eliminates failure mode of engine overheating with a shredded/malfunctioning belt.
    If the belt goes, the dash lights up due to alternator failure. What will be the comparable "tell" with an electric pump?
    Luke S :: 10270 :: 82 Grey 5-Speed :: Single Watercooled T3 .60/.48 :: Borla Exhaust :: MSD Ignition :: MS3X Fully SFI Odd-fire EFI :: DevilsOwn Methanol Injection

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  5. #5
    Delorean Guru
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    It adds additional load to an already overloaded electrical system. For all of the work and expense, IMHO it isn't worth it. You would also have to figure out how to run the alternator without the water pump. Could be as simple as just getting a different size belt. The water pump is very simple and reliable as it is. If you are doing it because it is an interesting project, go for it.
    David Teitelbaum

  6. #6
    DMC Timeless's Avatar
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    Quote Originally Posted by FABombjoy View Post
    I would take all that money you're going to spend on AN fittings, hoses, electric pump, wiring, etc., and put it toward EFI instead
    +2. This is a FANTASTIC idea.
    ~LXA~

  7. #7
    EFI'd dn010's Avatar
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    See post #3.

    Quote Originally Posted by David T View Post
    It adds additional load to an already overloaded electrical system. For all of the work and expense, IMHO it isn't worth it. You would also have to figure out how to run the alternator without the water pump. Could be as simple as just getting a different size belt. The water pump is very simple and reliable as it is. If you are doing it because it is an interesting project, go for it.
    -----Dan B.

  8. #8
    Member gongloo's Avatar
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    Thanks all for your great responses thus far. Very interesting discussion!

    Quote Originally Posted by dn010 View Post
    You will still need a belt to run the alternator so you'd need to figure that part out as well. Might be simple as getting a smaller belt for just the crank to alternator unless the angle of the tensioner doesn't allow it to work.
    Yes, I'd want to try to find a belt that is the right size to run the alternator directly off the crank without any other idlers or pulleys. I assume that the angle of the tensioner would not be a problem, but perhaps this is a poor assumption.

    Quote Originally Posted by dn010 View Post
    You'd probably want coolant to circulate when the engine is running so that you don't get hot spots in the engine and all sensors get the same temp coolant.
    Good thinking, I hadn't considered hotspotting! I'll update the original post with a note to this effect.

    Quote Originally Posted by dn010 View Post
    You'd probably not want to run the pump when the engine is off unless you also plan to have it run cooling fans at the same time [battery strain].
    I think a few amps for a minute or so shouldn't really strain the battery too much, but of course that depends on the battery system.

    Quote Originally Posted by dn010 View Post
    How often do you plan to access your VOD for maintenance that justifies removing the pump and redesigning the cooling system?
    Yearly, because I'm anal. Monthly if it's trivial to reach right in!

    Quote Originally Posted by dn010 View Post
    Just a preference, but I would rather have a mechanical pump that slowly indicates it's need for replacement [by weeping] over an electric pump that either works, or it doesn't, and usually the doesn't part comes at the worst times.
    Yeah, I'm not really familiar with the failure modes of electric pumps, so that's totally worth considering further. Lots of cars now exclusively use electric water pumps stock, and it seems for extra insurance some of them include a flow meter to throw a CEL when they malfunction. Hooking something like that up to the fan fail circuit would be fairly trivial, and possibly wouldn't even require a flow sensor (sensing voltage/amps across the pump might be sufficient, depending on failure modes). Lots of food for thought here!

    I'm so sick of coolant leaks at this point, though, and totally wouldn't mind carrying an extra small, light electric pump in the trunk as a backup (instead of the emergency coolant bottle I currently carry), especially if it's fairly trivial to replace. Wouldn't be the first time I've had to replace a component like that on the car at the side of the highway (last time was the alternator).

    Quote Originally Posted by FABombjoy View Post
    I would take all that money you're going to spend on AN fittings, hoses, electric pump, wiring, etc., and put it toward EFI instead
    Why not both? :-P

    Quote Originally Posted by FABombjoy View Post
    #6 would just put you back in to warm-up mode faster and decrease efficiency. You want the engine up to temp as quickly as possible.
    I'm not talking about bringing the engine way down in temperature; I'm just talking about reducing hotspotting after shutdown. Definitely less of an issue for naturally aspirated engines (which, to be clear, mine is), but nevertheless seemed like a neat trick to help a little bit with longevity. Maybe just a minute or so of circulating coolant post shutdown.

    Quote Originally Posted by FABombjoy View Post
    It's aluminum tube and can't weigh more than a few pounds.
    I'm concerned less with the tubing weight and more with the water pump weight and location. That unit is surprisingly heavy! Honestly, though, I'm way less concerned with the weight than the other thoughts I had above. In particular, I hate that the system has that many hose connections in it. My aluminum tubes are also a bit pitted and worn, so getting a great seal on them is a pain. Could I replace the aluminum lines? Sure, but where's the fun in that?!

    Quote Originally Posted by David T View Post
    It adds additional load to an already overloaded electrical system.
    This is definitely one of my bigger concerns. Even the new DMCH alternators are a bit anemic for the car, in my opinion. I've switched several components to reduce electrical load (LEDs all around including headlights and high beams, modern fans, etc.) but still see the electrical system taxed with the AC on at idle. Looking forward to throwing in Dave McKeen's Idle ECU with idle speed bump on AC signal for this reason. If I go down the electric water pump route further, I'll definitely be taking some very specific measurements around electrical load and capacity before committing. Perhaps there are direct fit higher-amp alternators around that I'm not aware of; if so, I'd like to install one regardless.

    Quote Originally Posted by David T View Post
    If you are doing it because it is an interesting project, go for it.
    Nailed it. That's what this whole thing is about!

  9. #9
    Administrator Ron's Avatar
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    Quote Originally Posted by gongloo View Post
    Would love to hear your thoughts...
    It looks like you have several bad circuits to me, E.G., the radiator's inlet and outlet are virtually connected to the same place, the thermostat outlet(s). I guess you could add restrictor passages, but that would be a nightmare to figure out...
    (Easy to see the flow if you redraw it where the pump is a battery and the rest of the components are light bulbs.)

    The otterstat should be immediately downstream and close to the thermostat.
    Actually, it's in a bad place already. Ideally, it should be in one of the heads (replacing it with a sensor, as previously suggested).

  10. #10
    EFI'd dn010's Avatar
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    I'm sure you already know this but higher amp alternators won't fix how they wired up the car, the size of the wires they chose to use and corroded/dirty connections, etc.
    -----Dan B.

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