If someone is building an FE today they should consider all that is involved.
That being said there is no reason to run a stock 40 psi oil pump even in a mild 390.
The B pump will put the needle at 60 + psi at 4000 rpm.
Here is some test data.
Small Chev test engine, but still good data.
""Re: oil pump volumes
Postby 540 RAT » Tue Jun 07, 2011 2:16 pm
When it comes to discussing/debating the topic of “std volume oil pumps vs high volume oil pumps”, we need something more than just opinion and speculation. We need some actual real world data. So, consider the following:
About a year and a half ago, Car Craft Magazine used a 372ci SBC to do an oil pump volume comparison test. So, we can look at that actual data to see how things stack up. Here are the results using conventional petroleum 30 wt for each test:
Oil Pump……………………........Peak HP………………Ave. HP……………Ave. press.
Std volume/std pressure.……….485……………………...392……………………..50 psi
High volume/High pressure…….481……………………...390……………………..66 psi
High volume/std pressure………477……………………...387……………………..64 psi
As you can see, surprisingly the std pressure version of the high volume pump made the worst HP of these three small block pumps. It was down 8hp or down 1.6% for peak HP, and down 5hp or down 1.3% for Ave HP. It also provided a 14 psi increase in ave pressure, or a 28% increase in ave pressure.
But the High volume/high pressure pump was down only 4hp or down .8% for peak HP, and down only 2hp or down only .5% for Ave HP. This one provided a 16 psi increase in ave pressure, or a 32% increase in ave pressure.
Of course the most important number is the “average” HP loss, NOT the peak HP loss. Because peak is only a single data point, while average is across the whole rpm range being used.
Only the most hardcore racer could ever notice a 2hp or .5% HP loss, using the high volume/high pressure pump. So, using that pump does NOT cause a significant loss in performance. And the higher volume pump will provide better low rpm oil pressure, and allow for switching to the much better thinner full synthetic oils that are available. More on that below:
And in the same article, Car Craft also tested different oil viscosities using the High volume/std pressure oil pump. Here are those results:
Oil…………………....Peak HP…………Ave. HP……………Ave. press……..Ave. Flow in GPM
0W10 syn……………...480………………….387………………………56……………………..7.4
5W20 syn……………...479………………….386………………………59……………………..7.2
20W50 syn…………....477………………….387………………………67……………………..6.5
30W conventional……475………………….384………………………67……………………..6.1
The 0W10 is probably thinner than all but the hardest of hardcore racers would care to use. And 20W50 is thickish and somewhat similar to the straight 30W.
But 30W conventional petroleum oil was used for the oil pump volume test at the top, so let’s use that as the main reference here for viscosity comparisons. And that leaves the more reasonable 5W20 synthetic for a quick viscosity comparison.
The 5W20 made 4hp more peak HP or about .8% more peak HP than the 30W. It also made 2hp more ave HP, or .5% more Ave HP than the 30W. So, HP increases with the thinner oil is not significant here, but it does offset the slight loss of hp from going to a high volume pump in the first place. The thinner 5W20 also drops a little oil pressure, but it’s still quite reasonable.
So, a larger volume oil pump loses a tad bit of HP and increases the oil pressure, but the thinner synthetic oil gains a tad bit of HP and decreases the oil pressure. In the end, it’s all pretty much a wash. So then what’s the point of making these changes at all?
To answer that, we need to look at the average flow in GPM (gallons per minute). The 5W20 flows a whopping 18% more than the straight 30W. So what’s the value in that you ask?
Well, many folks think that pressure = lubrication, but that is simply not the case. Pressure is only a measurement of resistance to flow. FLOW is the only thing that lubricates, and you get more flow with thinner oil as we just saw above. Lubrication is what is used to separate moving parts, and keep them from touching.
And increased flow also has another very important advantage. An engine's vital internal components are all DIRECTLY OIL COOLED, but only INdircetly water cooled. And thinner oil will flow more freely, carrying away more heat, thus providing better cooling for those vital internal components. And of course that extra cooling is even more important in high performance engines.
So, going to the trouble of achieving almost an extra 20% in flow, is well worth the effort. If someone asks why use a high volume pump, the answer is so that you can maintain reasonable oil pressure with thinner oil. And with thinner oil, you can improve both lubrication and cooling. So, it’s all good.
NOTE: To best see those oil temp changes and cooling improvements, you really need to observe that in a running car on the road or on the track. Because trying to observe this during brief dyno pulls, will likely result in you not getting a worthwhile picture of the true potential.
So, here are some comparison numbers for you from an 830 HP road race engine, on the track:
15W50 oil = 80 psi = 265* oil temp
5W20 oil = 65 psi = 240* oil temp
Here you can see how the thicker oil flowed more slowly through the bearings, thus getting hotter and driving up bearing temps. If an engine is running hot, use a thinner oil to increase flow and increase cooling. And running a high volume oil pump allows you to do that.
For me personally, I run 5W30 synthetic in my 781 HP, 710 ft lb, 540ci BBC Street/Strip motor, which I intentionally built with .003 clearance on the rods and mains. And with a Titan gerotor high volume oil pump, it has a hot idle oil pressure of about 30 psi, and a max oil pressure of 80 psi.""
Full Thread here:
http://speedtalk.com/forum/viewtopic.php?f=1&t=27041
