overheating & electric water pump?

[cortina1]

I am running a Spyder which is prone to overheating if sitting still for any length of time, fans trip in okay, but temp keeps rising, only remedy i found was to switch fans on manually when I anticipated getting stuck in traffic or shutting down the engine. I have recently plumbed in a Davies Craig electric water pump, mounted as low as possible and removed thermostat and disconnected the mechanical water pump via fanbelt, however I have not been able to get the EWP running without it apparently cavitating and thus getting air circulating around which you can hear....any advice appreciated,

[r5gttgaz]

correct me if im wrong its not a wise idea to run with out a thermostat

[GreenV8S]

If I were you I'd keep the mechanical pump, the little DC pump is fine for gentle part throttle low rev pootling in traffic, but you need the oomph of the mechanical pump to give the full water flow under power. I'd also suggest you keep the stat, without that you will suffer from overcooling. If you use an EWP controller to get around that then you will get even less water flow through the heads when there is ample radiator cooling capacity, which exagerates the problems of using an EWP. Basically think of the EWP as a booster pump that increases the water flow at low RPM and strangles it at higher RPM and you won't be far wrong.

Your EWP is unlikely to suffer from cavitation, but unless they are mounted the right way up they will suffer from an internal air lock which prevents them from self-bleeding. Ensure the pump is oriented so that air inside it naturally flows up and out of the outlet. If that still doesn't do the trick then check the logic of the EWP installation to ensure that you haven't accidentally knackered the logic of the vent/degas circuit.

[stig]

I tried a Davies Craig EWP in the GTR - total waste of time

The solution was probably collective rather than a single fix. I uprated the rad fans, cermakromed the exhausts, used water wetter (didn't make any difference by the way), thoroughly bled the system (make sure heater is on when doing this) and finally, richened up the idle mix.

Trouble with the EWP is that whilst it gives good flow at idle, it's less efficient than a mechanical pump at revs, where it ends up impeding the flow!

[gtrclive]

Well thats why GM used a EWP as standard on the Generation 4 Corvette's ?? The Criag Davis pump doesn't flow very well under pressure but it's not the only EWP on the market......

[stig]

gtrclive said:

Well thats why GM used a EWP as standard on the Generation 4 Corvette's ?? The Criag Davis pump doesn't flow very well under pressure but it's not the only EWP on the market......

Hardly a valid comparison Clive seeing as we're talking about an SBC in a Sport, not an LT1.

Just imparting my experience with the EWP.

[gtr-gaz]

Adam (layada) had a similar problem with his Spyder when I saw him at the Lavenham show last summer.

He seems happy with it now, although I have not seen the mods made. www.pistonheads.com/gassing/topic.asp?h=0&t=206653

Gary

[layada]

Garys right - upgraded rad and fans seesm to have sorted it (although I've not been out on a really rosting hot day as yet).

Some b*$ta3£ sole my digital camera - so I've not had a chance to put up shots of the system. However, if you would like to see the installation, I'm sure we could arrange a time for a visit.

Adam

[cortina1]

many thanks for the quick replies, will try a run with the mechanical pump reconnected with thermostat and use ELP when temp hits 100, although weather just now is not exactly a good test for getting stuck in a traffic jam in the summer. Welcome any more comments and may I say that I am very impressed with the Ultima forum - its my first use of any type of forum- great stuff, keep up the good work!! regards, Mark

[tjb]

I had overheating problems with my Sports and the two things that made the biggest difference were uprating the fans to Pacet Profans and panelling in the gaps at the sides of the rad.

[stig]

Yup - I also uprated the fans to Pacet Pro's which had twice the flow of the originals.

[peterpsg]

Did you guys happen to have the part/model number & size of the fans you used handy?
(Or should Pacet know which ones are suitable?)

Also roughly what did they cost for a pair?
(As I have to run all the Ult's costs past the other half these days! Grrr!)

Cheers,
Pete

Ok, I found the part number on an earlier thread! So no worries... KPF1011P here I come...


>> Edited by peterpsg on Friday 6th January 11:24

[layada]

Reprint from an old thread of mine.... I did a lot of research before purchase. Note the uprated rad takes three not two fans..

"
For those of you out there with older models that may suffer overheating problems I've discovered that it is possible to uprate the standard motors when you order new pacet profans direct from the manufacturer. Useful if, like me, you are space limited on fan diameter.

I've just ordered three of the 295mm fans with the "602" motor - after discussion, I believe the most powerful they supply.

Added as postfix to the part.

eg PK1111P/602

Hoping that and the new ally rad will do the job.

Beware of the v.high current draw though - you may need a relay on your fan switch.

Adam"

[tjb]

Just checked and my Pacet delivery note said:

10" X 11 PROFAN ASSY PULL 12V - Stock code PF1011P

so your details from the earlier thread should be ok, though mine don't have a K at the front of the code

Can't remember the price and can't find the invoice, sorry.



>> Edited by tjb on Saturday 7th January 18:38