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Davies Craig electric water pump: I am trying and failing...

Posted: Mon May 28, 2018 1:14 pm
by renaldo
Guys, trying to install a Davies Craig electric water pump on my Ginetta G15.

All going pretty well except that I'm having trouble with the new alternator belt size.

The way I'm installing required removal of stock pump and pulley.

Now down to two pulleys: 2.5" alternator pulley and 5" crank pulley.

That requires a much shorter belt. Plus, the alternator adjustment, which is set up for 3 pulleys, is minimal for 2 pulleys.

I might have 1/2" adjustment, but not much more.

The belt looks like it should need to be about 30" total circumference, versus over "40 for the stock belt.

Anyone do this conversion? Any help or guidance on how to deal with these issues?

Thanks a million!

Re: Davies Craig electric water pump: I am trying and failin

Posted: Mon May 28, 2018 3:31 pm
by The Nun
You can get a belt virtually whatever length you need, they are numbered up eg 1010 means it's 1010mm long if you need a 30" you'll be looking at a belt around 760

Re: Davies Craig electric water pump: I am trying and failin

Posted: Mon May 28, 2018 7:31 pm
by Keith 'Supaimpy' Laming
Or simply replace the pump with an idler pulley mounted on a plate using the pump fixings

Re: Davies Craig electric water pump: I am trying and failin

Posted: Mon May 28, 2018 8:35 pm
by renaldo
Thanks all for your advice.

I drove plenty of miles today to pick up an assortment of belt sizes, all in the vicinity of the size I likely needed.

One of out the 5 fit! Took lots of coaxing, boiling water, stretching and slippery detergent.

Can't adjust it much, but just enough I think.

Project passes another hurdle.

Start up, bleeding air out and sundry tomorrow...

Fingers crossed!

Re: Davies Craig electric water pump: I am trying and failin

Posted: Mon May 28, 2018 10:43 pm
by Lotus-e-Clan
Also consider this:

The DC EWP80 draws 7AMPS at full flow. This is significant for a low torque Imp engine.

When you add-in the current draw for wipers, heater blower, and lights on a cold dark night, the current draw is enough to significantly lower engine idle speed - enough to stall.

For this reason I fitted a 4 inch alloy pulley to the alternator to reduce the torque sap on the engine at idle. I also increased idle speed to 1300 rpm. A hot cam will like the increase in idle speed and the alternator will remain within 'charging revs' using the bigger 4 inch pulley with a higher idle speed. No need to wory about overheating in traffic using a high engine idle because the EWP80 can deliver full coolant flow at idle unlike the OE mechanical pump which struggles to flow properly at engine idle.

Of course if using a temperature controller you will not be drawing 7 AMPS all of the time - but it ill happen sooner or later!
Clan004

Re: Davies Craig electric water pump: I am trying and failin

Posted: Tue May 29, 2018 12:22 am
by renaldo
Thanks Lotus. Things I didn't know or hadn't considered.

I assume from your post though, you like your EWP over stock?

Ron

Re: Davies Craig electric water pump: I am trying and failin

Posted: Tue May 29, 2018 7:51 am
by Lotus-e-Clan
renaldo wrote:Thanks Lotus. Things I didn't know or hadn't considered.

I assume from your post though, you like your EWP over stock?

Ron
Yep I have had an EWP80 on the Lotus and Clan since 2004. Still going - very reliable (so far). The one on the Clan is an original non-ceramic bearing item.

They are both now pushing more viscous coolant (Evans Waterless) so they may suffer in the near future. Davis Craig thinks Evans will shorten the service life. We will see. Clan004