Water pump - electric

[Lotsof 3146 R]

Lotus Europa twin cam special coming out of twenty years hibernation.
The water pump is seized, but not leaking externally and there is no water in the oil.
Can I fit an electric pump without removing the original?
I be grateful for any feedback or experience.

[Grumblebuns]

I'm thinking of doing the same to my TCS after my engine rebuild. My concern to leaving the original water pump in place is the impediment to flow with the stock impeller in place. Also the seal  may not be leaking now but how about further down the road.

 

[Lotsof 3146 R]

I have found the following information from https://daviescraig.com.au/electric-water-pumps
DISABLING THE MECHANICAL WATER PUMP
Leaving the mechanical water pump in place, install the EWP® into the bottom radiator hose and remove the manufacturer’s thermostat.
You will need to bypass the water pump pulley by installing an appropriate length belt. This method makes for an easy installation.
If running the pump continuously, remove the thermostat and drill two approx. 3mm (1/8") holes in the thermostat plate to allow some coolant circulation. Re-install ensuring that the thermostat housing is clean and a new gasket is used if required.

What is not clear is if this would still apply to a seized water pump; any experience with EWP on the twin cam would be much appreciated.

[andy harwood]

I used a EWP pump and controller in my TCS. I removed the water pump belt, and the mechanical pump freewheeled with the EWP water pump flow. I had no issues, except getting all the air out of the system. It was nice with the controller - you could hear it ramping up flow, and starting the fan with temp changes. Also, the controller ran for a few minutes after shutdown to cool the engine a bit. With the impeller frozen, seems that would impede coolant flow greatly.

[Lotsof 3146 R]

Many thanks for letting me know, I have decided that EWP is the way  to go and ordered the parts; if I’m lucky it’ll work; if not, it’ll be engine out and mechanical pump removed.
I’ll update in due time

[magno_grail]

Every engine driven water pump that I have seen is a centrifugal type. Most have straight vanes, a few have curved. Coolant can flow between the vanes without the impeller running. it does not matter if the pump is seized.
To take out the impeller usually requires pressing off the pulley and taking out the sealed bearing that it is attached to. Then the bearing hole has to be plugged. You might be able to press it off the shaft or break it.
Porsche was clever enough on the Boxster to use a plastic impeller so when the bearing went out it did not take out the engine case.

[Lotsof 3146 R]

So its fitted, the engine has run up to temperature for the first time in perhaps 10 or 20 years and yippy it works!
No leaks, no water in oil or oil in water and the old mechanical pump remains seized solid.
And the engine sounds sweet with good oil pressure.
Early days - I'll post an update once she's back on the road

[Grumblebuns]

Good job. Were did you install the pump?

[Lotsof 3146 R]

Good job. Were did you install the pump?

On the bottom radiator hose. I fitted a new aluminium radiator and fan at the same time.
The standard EWP 80 comes with a one straight and one 90 degree flange. This is not optimal (and I'm not posting photos of this lash-up:-) ) I have a straight flange on order from the UK importer  http://www.mawsolutions.com/index.html

[Grumblebuns]

The lower radiator hose seems to be the easiest place to plumb in the EWP. The biggest issue that I've read is the possible loss or reduction in coolant  flow for the cabin heater due to the change in differential pressure across the heater core. I'm very curious if you experience this phenomenon. My plan is to plumb mine in at the inlet to the normal inlet to the engine, at the timing chest.

   

[Lotsof 3146 R]

Quick and easy installation of an electric water pump and associated thermostat

[Rosco5000]

I love the electric pump idea!  The work you have done looks very good.  I do have one question though if I look at the diagrams on the water pump website has online the outlet pushes towards the engine and sucks from the radiator, the way you have this installed the opposite is happening.  You are sucking from the engine and pushing coolant into the radiator.  Can the system flow either way?
Cheers,
Ross

[rascott]

i fit mine at the radiator.

the temp control sensor is in the head, the fan control is still in the radiator.
i'm still turning the waterpump, 'cause the alternator is driven by the wp pulley.
hmmm. the pic is bigger than usual. another mystery.

[Grumblebuns]

I love the electric pump idea!  The work you have done looks very good.  I do have one question though if I look at the diagrams on the water pump website has online the outlet pushes towards the engine and sucks from the radiator, the way you have this installed the opposite is happening.  You are sucking from the engine and pushing coolant into the radiator.  Can the system flow either way?
Cheers,
Ross

From the way I see it, both installations have flow going in the correct direction, normally coolant from the engine enters the radiator from the bottom hose and goes back to the engine from the top hose. Lotsof has his pump plumbed into the bottom hose sucking from the engine discharging into the radiator. rascott has his pump plumbed into the top hose sucking from the radiator discharging back to the engine.

This is for the twin cam.

[MRN I J]

I love the electric pump idea!  The work you have done looks very good.  I do have one question though if I look at the diagrams on the water pump website has online the outlet pushes towards the engine and sucks from the radiator, the way you have this installed the opposite is happening.  You are sucking from the engine and pushing coolant into the radiator.  Can the system flow either way?
Cheers,
Ross

From the way I see it, both installations have flow going in the correct direction, normally coolant from the engine enters the radiator from the bottom hose and goes back to the engine from the top hose. Lotsof has his pump plumbed into the bottom hose sucking from the engine discharging into the radiator. rascott has his pump plumbed into the top hose sucking from the radiator discharging back to the engine.

This is for the twin cam.

Almost right, hot coolant is pushed out of the top of the engine into the top of the radiator, the radiator cools the coolant because the opposite of heat rises occurs so cooling lowers,  the cooler coolant is then sucked from the bottom of the radiator to the (normally) lowest place in the engine, the water pump inlet, the water pump then pushes the coolant through the engine, through the thermostat / bypass system, through to the top of the radiator starting the cooling process again.