chris_barry

Having problems maintaining oil pressure above 60psi with my dry sump system at high rpm. I suspect that the pump stage is undersized and cannot keep up the oil flow required once the VTEC solonoid is switched and the rpm increases (pump efficiency drops with speed). Have tried different oil grades and the scavenge side seems to be working.

Does anyone know what the oil pressure flow rate/volume is for a stock engine oil pump. Normal dry sump pumps have ratings like 18 GPM @ 4000rpm.

I was going to measure up the flow of the stock pump. Does anyone know what the speed ratio of the oil pump to crank is?

Thanks

Chris.

chris_barry

Found the information

The standard F20C pump runs at 21/34 the crank speed.

It pumps 6.5ml oil per revolution

So at 9000rpm its moving approx 36litres pre minute, approx 10 gallons/minute.

The pump is a concentric rotor style so is very efficient.

Chris.

davepk

Chris

That 21/34 should be 34/21.

21 teeth on the oil pump, 34 teeth on the crank.

Comes out to about 95 l/min

chris_barry

Dave,

Well spotted. So used to reduction ratios I got my numbers reversed.

That pump is certainly moving a truckload of oil. Probably explains why the 18 GPM pump cant maintain pressure. 95L/m is around 25 GPM

Chris.

Slows2k

Moving to Technical

PSC

In the (2000- 2003) service manual

Section 2-10 "Specs"

Design Specifications -> Engine -> Oil Pump Displacement :

@ 6000 RPM, 58.4L per minute


-- Paul