12V electric Water pumps - how are they fitted

[PeeBee]

I went through this exercise some years ago (not with a Patrol though). I inserted a Davis Craig in line electric pump. This pump arrangement worked well because with the electric pump OFF, the original mechanical pump worked "through" the electric pump. With the pump ON (when the engine was working hard) it obviously greatly increased the water flow, but it only reduced the water temp by a small amount because there was not a lot of time for the heat transfer to take place in the radiator. To solve this I purchased a more efficient radiator and turned it into a Triple Pass radiator. The coolant stayed in the radiator much longer and all my overheating problems went away.

Thanks for that info, as it kind of rings a few bells. I think the super radiator Brunswick Diesel sell now for the conversion is a quad pass alloy unit. Its around the $1800 mark but it works I am told from a guy who shelled out for one.

[the evil twin]

Muddy, have a read of the info from the link I posted, they pose some counter arguments to that hypothesis that seem reasonable and slap that fix out of the park.

I read it a couple of days ago and was dubious of the claims then and I still am... depending on context
Also Flowkooler don't have the greatest of reviews that I can find after an albeit cursory search which turned me off as well.

I agree with them in one area tho and it is to do with existing pump flow capacity as I work on 'weakest link in the chain' theory.

In the case of the 6.5 cooling, originally it was the 'old' thermostat design so they came out with the twin hi flow.
Then the weakest point became Rad efficiency.
Logic would say to me that if changing the pump capacity would allow the 6.5 (and for that matter TD42 or any engine with a cooling issue achilles heel) mean you don't have to arse around with different thermos and thousand dollar Rads then Messrs Chevy/Nissan et al and any major aftermarket mob would have been all over it.

BillsGU experience is exactly what I would expect ( a small improvement) unless the existing pump was the lowest efficiency component in the system, in which case you would get a large improvement.

To me, logically, it is sort of like to winding up the Turbo Boost rather than fitting a better Intercooler when attempting to reduce EGT.

I haven't seen all that much on the Chev Forums about dual pumps or elec/mech hybrid either, other than the hi flow impellors which I would def consider

[PeeBee]

I went through this exercise some years ago (not with a Patrol though). I inserted a Davis Craig in line electric pump. This pump arrangement worked well because with the electric pump OFF, the original mechanical pump worked "through" the electric pump. With the pump ON (when the engine was working hard) it obviously greatly increased the water flow, but it only reduced the water temp by a small amount because there was not a lot of time for the heat transfer to take place in the radiator. To solve this I purchased a more efficient radiator and turned it into a Triple Pass radiator. The coolant stayed in the radiator much longer and all my overheating problems went away.

Bill can you supply me some additional info on exactly what you did, how and what a triple pass radiator looks like and is configured, or did you buy it from someone, and lastly what similarities was your problem cooling to what a few of us are experiencing?

[Rossco]

Here's a link to Aussie Desert Coolers one I remember perusing a while ago. . .

http://www.aussiedesertcooler.com.au/triple-flow.html


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[nissannewby]

You cant really have too much flow. Maybe if the system cannot handle the amount of flow going through it. The temperature drop across the rad will remain much the same irrelevant of flow. 10 degrees is usually normal. If you can get 15 degrees you are doing well.

Davis Craig do some nice units for water pumps. I would be using the pump on its own removing the water pump impeller and thermostats. Use the davis craig supplied controller and plumbing instructions and it will be fine. You can save some hp hear as the pump will only operate when its required. It will not turn fully off though it will pulse the fluid through the engine as to keep the fluid temp more stable. A 150Lpm unit would prob suffice on the slow old lump that is a 6.5 chev.

One thing I think you should also be looking at is chemical cooling as an intercooler. Using water or a water/methanol mix. This evaporative effect will have intake temps right down. Especially since you are using a supercharger.

[PeeBee]

You cant really have too much flow. Maybe if the system cannot handle the amount of flow going through it. The temperature drop across the rad will remain much the same irrelevant of flow. 10 degrees is usually normal. If you can get 15 degrees you are doing well.

Davis Craig do some nice units for water pumps. I would be using the pump on its own removing the water pump impeller and thermostats. Use the davis craig supplied controller and plumbing instructions and it will be fine. You can save some hp hear as the pump will only operate when its required. It will not turn fully off though it will pulse the fluid through the engine as to keep the fluid temp more stable. A 150Lpm unit would prob suffice on the slow old lump that is a 6.5 chev.

One thing I think you should also be looking at is chemical cooling as an intercooler. Using water or a water/methanol mix. This evaporative effect will have intake temps right down. Especially since you are using a supercharger.

Thanks Matt, I did make contact with SNOW regards a kit when the vehicle was N/A but they said they did not have a kit. I dont know if it was the lack of electronics or ability to meter the flow which a few of their system use, but might give them another shot. Its funny, I had not even thought about removing the impeller, makes total sense. I need to check the specs with Brunswick Diesel first as the new pump is I think 130gpm(520lpm), as opposed to the existing at 65gpm(260LPM), but these figures are huge compared to a Davis Craig pump you recommend. Something is not right. Right now I get 11 to 12 deg differential across the radiator.

With the cooling, I assume the liquid sprays into the manifold as the S/C sits directly on top of the engine valley? Do you have a recommendation on a system? - or do you spray pre the s/c into its inlet?

[the evil twin]

Uuuuummmm... if more flow is good then how is replacing a 260LPM mech pump with a 150LPM eleccy going to help at anything more than low RPM?

Eleccy pumps are mainly touted to, increase power and/or increase fuel economy by reducing driven load on the engine and increase engine life by reducing heat soak after shutdown.
Totally agree on those points.

I agree that more flow is a no brainer in open loop (Airflow thru the Rad) but would definitely question getting anything like the same efficiencies on the closed loop side (Coolant thru Rad) where the Rad spec is unchanged.

The coolant side works entirely on conduction so if the coolant stays in contact with the core for less time it must dump less thermal load but there is more coolant passing over the core thus there has to be a crossover point on the curves. Get on the wrong side of the crossover and flow will hinder not help

Multi pass Rads work on the principle of extending the contact time, the lower the coolant temp going in the more thermal load it can carry, the higher the coolant temp (say it is up near 110 degrees) the less load it can remove



Great discussion this, really has me thinking... :-)

[BillsGU]

Bill can you supply me some additional info on exactly what you did, how and what a triple pass radiator looks like and is configured, or did you buy it from someone, and lastly what similarities was your problem cooling to what a few of us are experiencing?

At the time I could not get a triple pass radiator at anywhere near a reasonable price so I purchased a new high efficiency radiator. I then turned it into a triple pass by using a hacksaw to put a cut in the top tank about one third of the way from the inlet. I then cut another slot in the bottom tank a third of the way from the outlet. I then cut some metal plates that fit into these slots and welded them into place, effectively blocking those parts of the radiator from the water flow.

Obviously in a normal radiator the water enters the top tank via the inlet, passes through the core, enters the bottom tank and then out the outlet (single pass).

In a tripple pass the water enters the inlet into the top tank, hits the barrier one third of the way along, drops through the core into the bottom tank, hits the bottom barrier and flows up through the core again into the top tank where it once again drops through the core, into the bottom tank and out of the outlet (tripple pass). As the water stays in the radiator longer there is more time for the heat to transfer to the core. I also upgraded the cooling fans to ensure better thermal transfer to atmosphere.

As I mentioned before this solved all the overheating problems I had at the time.

[PeeBee]

Many thanks Bill, another piece of the puzzle.

[nissannewby]

Uuuuummmm... if more flow is good then how is replacing a 260LPM mech pump with a 150LPM eleccy going to help at anything more than low RPM?

Eleccy pumps are mainly touted to, increase power and/or increase fuel economy by reducing driven load on the engine and increase engine life by reducing heat soak after shutdown.
Totally agree on those points.

I agree that more flow is a no brainer in open loop (Airflow thru the Rad) but would definitely question getting anything like the same efficiencies on the closed loop side (Coolant thru Rad) where the Rad spec is unchanged.

The coolant side works entirely on conduction so if the coolant stays in contact with the core for less time it must dump less thermal load but there is more coolant passing over the core thus there has to be a crossover point on the curves. Get on the wrong side of the crossover and flow will hinder not help

Multi pass Rads work on the principle of extending the contact time, the lower the coolant temp going in the more thermal load it can carry, the higher the coolant temp (say it is up near 110 degrees) the less load it can remove



Great discussion this, really has me thinking... :-)

I was not aware of the capacity of the chev pump in my statement. I have since had a look and the best I can find is a mech driven 130gpm. Which is a large quantity of water. A lot of the problem with a chev is the heads I believe. There were upgrades to the "HO" water pump and the twin thermostat housing which did seem to help.

The recommendation to run watet/meth injection would help to alleviate some of the heat the head would see due to intake charge temp. Combustion temps and cylinder pressure would come down taking some load off the cooling system. Water/meth can also have a steam cleaning effect due meaning can stay cleaner longer.