Technical Q: electronic water pump??

I wouldnt personally

We ran some tests on a Davis Craig pump to see if we could verify their claims.

We couldnt and there were some fundamental flaws in their thinking too....

It lost power not gained it, water temperature guage indicated it was doing its job, fully instrumented cylinder head on an engine dyno showed it very definately wasnt

Over time you would not do any motor a lot of good running one.

Stick with a mechanical pump, remote mount one if you have to, they do at least work ;D

Just my experience

The latest issue of PPC has an article about an electric water pump made by a comapny called MAW. It claims it moves 110 litres of water a minute and is suitable for engines up to 8 litre. Cost is a pretty steep £179 though. Phone number is 01273 493343.

I have PPC don't know how i missed it. will look at that tonight. I'd heard theres a new one out as it was spotted in Retro Cars, generally theres some bad feedback coming from the older ones at least. Hmm, back to the drawing board

HaHa

Just got hold of my ppc

internals are stainless, and its 179 quids.

other brands popping up elsewhere; www.aerospacecomponents.com/pumps.htm , www.stewartcomponents.net/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=ElectPump

It wasnt a rolling road it was a fully instumented engine on an Engine Dyno at Cosworth.

Pumps were specced to engine and coolant capacity and flow requirements

With Temperature probes in the head casting to measure combstion temps and the heat transfer to coolant.

Basically the Electric pumps were not moving enough water to get effective heat transfer out of the combustion chamber.
This in turn lead to power dropping off as temperatures rose and worse was microboiling of the coolant on the casting above the chamber which causes very fast erosion of the head casting.... this was found by cutting the (extremely expensive) head up afterwards to confirm an initial borescope inspection.

Not something you would show up on a rolling road, or a hillclimb or sprint for that matter

And not the kind of testing that an electric pump supplier is likely to do either.....

The first you would know about it is that nice, fully ported race head that cost you an arm and a leg has suddenly gone porous or cracked due to the casting wall being eroded away

Cheap horsepower then isnt it ;D

Here's the thing though:


But:


Perhaps they were specced in accordance with their makers guidelines, and the guidelines were ill-defined.

I like the idea of an electric water pump, got to be more efficient than an old mechanical water-wheel, agreed though that the ones on the market probably have not had a proper thorough evaluation process to match them correctly to whatever the water capacity/heat loss/flow rates etc etc might be of a certain engine. its got to be more complicated than ‘this pump shifts X litres/min and is therefore OK on engines up to Y litres capacity'.

Ive heard all sorts of problems with those davis craig pumps, autospeed australia did a test, anddecided that they didnt do their job. Davis craig the company then got all shirty and threatened legal action, autospeed has to withdraw the article. So Davis craig obviously knows that there is problems but they are just not willing to admit it.

Has anyone done any tests to see how much power a water pump draws? It must be quite a bit as water isnt exactly the least dense material to move around, so an electric one must be pretty powerful?

J

Ive got lots of turbo impellers hanging around, i wonder if a good water pump could be made from one of those?

J

edit -

I just found this, could be of interest?

www.projecttransam.com/projects9.asp

When it comes to the water pump in a cooling system then I think it's about one thing only, 'does it pump the necessary amount of water at the correct time'.
4,000 revs in 5th on a motorway needs less water pumped around(as the rad has more air through it = the water is cooler) than 4,000 revs in 2nd gear on a country lane.
In theory a well controlled electric pump should be the ideal.