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Durance oil pump differences


papak

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As I go about building my first Duratec (2.3l), I am trying to find out what differences exist between the standard pump and the "high output" one. Does anyone have any factual information regarding the differences? is there any external dimensional change?

 

TIA

Edited by papak
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With absolutely no expertise at all, I'll offer a differing point of view. IF (that is a big IF) the engine is in good nick, any extra volume provided by a larger oil pump is just wasted HP that doesn't get to the wheels. It won't provide any higher oil pressure than the pressure regulator is set for. Contrary to popular belief, the rotating parts etc do not ride on the flow of the oil. They ride on the molecular film that is wetted to the metals. As long as oil is getting to the last bearing, not much more can be attained with a higher volume pump.

 

That is all predicated by the basis that everything in the engine is in good condition. Worn parts require higher volume to get the oil to the last bearings in the oil galleries. Some well respected people claim that 10 PSI for every 1000 RPM (up to the pressure relief setting) when the engine and oil is hot is enough pressure to do the job. Look it up. It is on the internet. It must be true. That may be a simplified rule of thumb. And may not fit all engine designs.

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  • 2 weeks later...

I have tested both pumps for the Duratec , I didnt see any higher psi and when I tested for volume I didnt see a gain , why they call it high output I dont know

 

Yes they are made for the Turbo Duratecs

 

I dont use them because they cost a little more , most shops install them either because they dont test to see what they actually do or to charge more for the job

 

Use the stock pump and you will be fine , if your going to go over 7400 RPM go to a dry sump there are some nice ones out there for the Duratec

 

I also agree with the rule of thumb of 10psi per every 1000 RPM but thats for oil psi not to get confused with oil Volume

 

Tom

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I also agree with the rule of thumb of 10psi per every 1000 RPM but that's for oil psi not to get confused with oil Volume

 

I may be looking at this oil volume all wrong, but here is how I see it.

 

Pressure and volume are interrelated, at least until some form of regulating device is put into the circuit. Assume the oil galleries are operating at some fixed temperature and RPM, they will provide some fixed resistance to oil flow. If the oil pressure relief valve has hit it's operation point, say 60PSI, any excess "volume" will just have to be returned to the sump via the bypass route. The larger pump will do nothing for the bearing and journal lubrication and since there is no more flow thru them, nothing for cooling. When operating below the pressure relief valve setting a higher volume will provide more flow, and as a result, more cooling.This is wasted energy. The engine has to use more if its available HP to drive the larger pump, making less HP available for the wheels.

 

Just my thoughts.

Chuck

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I'll add my two cents. The flow at any given pressure is regulated by resistance.. Reduce that resistance, ANY resistance, and you will get better flow.

 

One of the ways that manufacturers keep production costs down is to feed the oil into a galley (channel) where it is used along the way by different users. The first user gets oil at full pressure/flow minus any resistance along the way. The second user gets oil minus the resistance to his location plus what the first user used up. And so on.

 

Some engine builders use a feed to the back end of the galley to add additional oil pressure/flow to the bearings that usually see the least.

 

Granted, most parts get all the oil they need in the normal operating RPM band. But who likes to hang around there in this group.

 

Tom

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I raced a normally aspirated 944 for 5 years or so. I got the car with 120k on the motor and the only failure I ever had was a pinion gear on a replacement LSD diff. I ran an air-oil separator, external cooler and a large Acusump with the stock oil pump. I probably had 10 qts in the system. It ran flawlessly.

 

I have an early Raceline wetsump that fits with the stock oil pump on the 2.3. I plan on adding an external cooler and a small Acusump after the break in. I'm rebuilding the engine with fresh bearings so I should be fine. I plan on keeping the redline at 7000 until I get bored and rebuild it from 200hp to 250-260 or so. Then I will add the dry sump etc.

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