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K20a2 oil pump flow gpm?

6K views 13 replies 7 participants last post by  LotusElise 
#1 ·
Does anyone know what is the oil pump flow in gpm?
I am trying to desing an oil cooler and need to know what is the oil flow.

Thanks,
 
#2 ·
I dont have my Helms here, but it is in the specs portion IIRC.
 
#4 ·
It is towards the front of the helms in the engine specs.

It is the second section, SPECIFICATIONS, under design specifications, Item Engine, and it is the oil pump displacement.

I dont have my RSX manual here at home but I do have a TSX Helms manual right here and it states at 6300 rpm 54.3L or 57.4 US qt per minute, just for infos sake.
 
#10 ·
For other people being routed here looking for answers: (from the FN2 manual)
Oil pump displacement​
At 6,000 rpm (min −1 )​
54.3 L (57.4 US qt, 47.8 Imp qt)/minute​
Water pump displacement​
At 6,000 rpm (min −1 )​
82 L (87 US qt, 72 Imp qt)/minute​
 
#11 ·
but that number does not correspond to the amount of oil flowing through the engine as most of the flow will be bypassed and recirculated through the bypass valve in the oil pump.
As the engine reaches max pressure beyond some 2000-3000 rpm depending on oil type used and the recirculation valve starts bleeding off excess flow, the true flow rates through the engine or oil cooler are rather 1/3 to 1/2 of what is stated above, so about 18-27 l/min.
The pump flows 2000/6000 * 54.3 l/min ≈ 18 l/min at 2000 rpm and 3000/6000 * 54.3 l/min ≈ 27 l/min.

Pressure is proportional to flow, so if pressure stays constant from a certain rpm onwards despite the pump pumping more because the record valve opens, flow through the engine is constant at any higher rpm.
 
#12 ·
For other people being routed here looking for answers: (from the FN2 manual)
Welcome @Tjaart to K20a.org. Thanks for your information.

but that number does not correspond to the amount of oil flowing through the engine as most of the flow will be bypassed and recirculated through the bypass valve in the oil pump.
This and another point:
  • oil pump has a positive displacement design, means rotation speed vs flow is roughly linear, each rotated volume get filled and displaced at the outlet, thence working pressure need to be controlled to safe the pump and the hydraulic system from excessive pressure
  • water pump has centrifugal design, means rotation speed vs flow is highly non-linear and highly working pressure depended, the higher the working pressure or pressure difference of in- versus outlet, the less flow will be pushed through the pump.
That means, like @Lotus indicated, the oil flow flux of the oil and the water pump can't be predicted easily for each system (oil and coolant) as both have system-dependent flow properties. The manual data are only for the pump itself at practically no pressure difference of in- vs. outlet (= for shop test reasons specified).

If one need data, one need to measure it for ones exact system (turbine based sensors are quite cheap) and are easy to implement in the circuit.
 
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