Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13

Thread: Coolant routing/flow?

  1. #1
    Member gongloo's Avatar
    Join Date:  Jul 2012

    Location:  Waltham, MA

    Posts:    41

    My VIN:    5879

    Coolant routing/flow?

    Having recently been into the VoD to deal with a leaky hose from the water pump, I thought it might be interesting to investigate relocating the water pump to the front of the car, with an aim to greatly simplify the system as well as to eliminate many of the pipes and hoses (instead just running AN fittings in as many places as possible), among other reasons. For starters I'm looking for a decent diagram and/or explanation of the routing of coolant (crucially with flow direction) through the car.

    So far what I think is going on (please correct me where I'm wrong):

    1. At the top of the water pump, there's the thermostat which, when open, allows the pump to push coolant through the otterstat on the driver's side of the car into the radiator.
    2. At the exit of the radiator, there are a couple of return hoses (bleed hose at the top), which run back to the water pump on the passenger side of the car. On this return, there's also a T which allows coolant from the overflow tank in to the loop.
    3. At the back of the engine towards the firewall, there's a hose allowing coolant to exit to the overflow tank as well as a hose to feed the heater core.
    4. There's a return from the heater core directly to the water pump, running through the valley.
    5. At the top of the engine on either side of the water pump there are feed hoses allowing the pump to push coolant through the engine.
    6. In the valley there are two return orifices that allow coolant to return, through the Y pipe, to the water pump.

    So in total I'm counting three outlets (1, 5) and three inlets (2, 4, 6) to/from the water pump.

    Do I have this right?

  2. #2
    Senior Member Bitsyncmaster's Avatar
    Join Date:  May 2011

    Location:  Leonardtown, MD

    Posts:    7,635

    My VIN:    03572

    I'm pretty sure the water pump is always pumping coolant through the engine and heater core even before the thermostat opens. So I can't see the improvement you would get by moving to a water pump to the front of the car.
    Dave M vin 03572

  3. #3
    Senior Member
    Join Date:  Oct 2016

    Location:  Fresno, CA

    Posts:    235

    My VIN:    10353

    What would drive the pump if you moved it? Can't see what the benefit of moving it would be.

  4. #4
    DMC Timeless's Avatar
    Join Date:  Nov 2016

    Location:  SW FL

    Posts:    208

    Club(s):   (DCF) (DCO) (DCUK)

    Quote Originally Posted by eight8toy View Post
    What would drive the pump if you moved it? Can't see what the benefit of moving it would be.
    Electric pump. I don't see a benefit either of moving it.
    Dunmurry | Stuttgart | Leipzig | Tochigi | Fremont | Crewe

  5. #5
    Senior Member
    Join Date:  Aug 2018

    Location:  Virginia

    Posts:    414

    My VIN:    1623

    If youíre looking for simplicity, wouldn't it be simpler just to maintain your cooling system? I canít imagine the engineering required to accomplish your idea.
    DMCF rebuild 2008, Stage II, Eibach

  6. #6
    LS Swapper Josh's Avatar
    Join Date:  Mar 2013

    Location:  SK, Canada

    Posts:    1,980

    My VIN:    11408

    Club(s):   (TXDMC) (DOI)

    It seems like you would complicate the system. The issue with the coolant system in a rear engined front radiator car is the length of piping from front to back.
    So unless you are going to put the engine in the front this seems like a futile effort

    If you want to relocate the waterpump, use an electric one.

    5.3L LS4 + Subaru 6spd 314whp/348ft-lbs
    Getting it back on the road!
    LS Swap

  7. #7
    Member gongloo's Avatar
    Join Date:  Jul 2012

    Location:  Waltham, MA

    Posts:    41

    My VIN:    5879

    Coolant routing/flow?

    Thanks all for the replies. I can see that literally everyone on this thread is focused on the relocation part, which is great to see comments about, but isn't the actual topic at hand: trying to understand the coolant flow.

    I'll be happy to start a separate thread specifically about pump relocation to explore the pros/cons of that, as I'm sure you all have lots of thoughts and considerations to raise that are definitely worth surfacing.

    In the meantime, I'd like to focus this thread on making sure that we clearly document the expected coolant flow through the various parts. It seems that might be useful to have well documented separate from any proposed modifications.
    Last edited by gongloo; 06-26-2019 at 09:28 PM.

  8. #8
    '82 T3 FABombjoy's Avatar
    Join Date:  May 2011

    Location:  Lansing, MI

    Posts:    898

    My VIN:    10270

    Imagine the radiator on the other side and the expansion tank on the return hose.

    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 - Game console parts, kits, games and more. [shop] [wiki] [RSS] [f] [t]

  9. #9
    Senior Member vwdmc16's Avatar
    Join Date:  May 2011

    Location:  sacramento

    Posts:    1,391

    My VIN:    1768

    Club(s):   (NCDMC) (DCUK)

    Yes your description of the coolant flow sounds correct.

    Water pump always flows water inside the engine, when it gets hot it flows to and from Radiator.

  10. #10
    Senior Member jamesrguk's Avatar
    Join Date:  Jun 2011

    Location:  England UK

    Posts:    221

    My VIN:    5462

    Club(s):   (DCH)

    is there anything inherently wrong with the original set up

    Is there actually anything wrong with the original design? OK having the radiator so far away from the engine isn't ideal, but most issues I hear or have experience (during 19 years of ownership wow where did that time go) of overheating are down to poor maintenance or parts that are simply old and wear out.

    A good stock cooling system should work fine, if you replace your radiator with a modern aluminum version and/or possibly upgrade the fans with items from your preferred vendor then even better.

    I think the O.P's idea is interesting for those who like a project for project's sake but I don't see any benefit in changing the stock setup.

    All this being said I always enjoy reading about a quirky project.


Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts