Davies Craig water pump (EWP)
The Davies Craig EWP is cooling's independence movement: the Australian electric water pump family (EWP115/150 the staples) that divorced coolant flow from crank speed — race cooling that works hardest exactly when engines idle hottest.
History
Davies Craig built its Melbourne business on a thermodynamic argument the belt-driven world ignored: mechanical water pumps flow with rpm, but heat rejection needs flow by temperature — worst at post-stage idle, grid waits and slow corners. The Electric Water Pump line (EWP80 through EWP115 and EWP150 by flow rating, with matching digital controllers) made coolant flow electronically commanded: full flow at zero rpm, controller-managed temperatures, and after-shutdown circulation that kills heat-soak — plus the parasitic-drag horsepower the deleted mechanical pump returns.
Motorsport adoption followed the argument's logic: rally cars (stage-end idle heat the classic killer), drag builds (cooling between runs without running engines), circuit racers chasing parasitic gains and packaging freedom (remote pump mounting liberates front-end design), and the kit/engine-swap world where the EWP solves plumbing a donor pump never suited.
As used equipment, EWPs are honest electricals: impeller and housing condition, motor function under load, controller pairing and plumbing-size match structure the market — with the firm's longevity and parts support keeping the ecosystem serviceable.
Palmarès
Cooling national rally, drag and circuit machinery across the Australian and international club scenes for two decades — the record of temperature crises that didn't happen: stage-end idles survived and heat-soak restarts that simply cranked.
What to check before you buy
Flow-match first: EWP models rate by litres-per-minute (115/150 the motorsport staples) — size against your engine's heat rejection honestly, because under-pumping cooks engines politely and slowly. Controller pairing matters (the digital controller's temperature management is half the system's point; pump-only purchases forfeit it). Test used pumps under load (bench-run: current draw and flow tell motor health), inspect impeller and housing for corrosion and cavitation wear, and verify plumbing diameter match to your system. Series legality is rarely an issue but check homologation-sensitive classes. New pricing is rational; used serves budget builds fine when bench-tested.
Did you know
- After-shutdown circulation is the EWP's party trick: coolant keeps moving through a dead engine, killing the heat-soak that warps paddock-parked alloy.
- The deleted mechanical pump returns real horsepower — parasitic drag at high rpm that dyno sheets actually show, cooling's rare free lunch.
- Melbourne's thermodynamic heresy took decades to mainstream — OEMs now fit electric pumps for the exact reasons Davies Craig argued in the 1990s.
In the marketplace now
View all →No exact Davies Craig water pump (EWP) listed right now — here is closely related machinery on the market.
