we have had this discussion a few hundred times and each time i implore you to just do the arithmatic to seperate the myth from the truth......

1) the galley size inside the block isn't even 1/2 " dia.

2) the maximum flow rate of any of these pumps that bolt inside the pan ( as in making no pressure at all just spinning at 3500 rpm and pumping into an empty bucket) does not exceed the flow rate of a 3/8 line at 90 psi.

3) the maximum flow rate required in the motor is that difference between what the pump makes for volume at a given rpm versus what bleeds out the bearings while still maintaining sufficient pressure.

4) line size only becomes critical when it is smaller than the internal passages of the block casting...

true and false quiz
putting larger lines on makes more pressure : false. line size has nothing to do with pressure in the motor as long as they can pass enough oil at the required pressure number to satisfy the bearing demand. anything larger than the minimum is meaningless.

angles in fittings reduce flow rate : true. however that has more to do with velocity rather than volume. in every application you will find from the factory, if you did the math, you would find that the reduction in area across one of their metal 90's while noticeable , is still more than 100 % greater than the area required at MAXIMUM.

putting bigger or better 90's will increase flow rate... true AND false. yes... in the first test where the pump is spinning and pumping into a bucket the flow rate/fill rate will be higher with a better fitting. but thats not what happens inside your motor. what happens inside your motor is that the pump moves 500 % more oil than it needs to. the bearings bleed such that the pump doesn't lock solid and the relief valve takes care of the rest. the actual velocity of the oil in the lines when the motor is running is actually quite slow... and thats why the steel 90's you see the factory use are completely adequate.

in short... if you assume that you haven't put gigantic clearences in the bearings ( and there is a great video on federal moguls web site where they demonstrate the diff in pressure very small changes in clearence make) and that you aren't running 200' of oil lines ( the longer the lines, the more parasitic drag) then a standard volume pump using the same lines and fittings that came with the motor are going to be fine. every single time.

if you want to know what size lines you need, make the inside dia the same size as the main oil galley in the block. anything bigger than that is just a waste of time and money.

all this changes if you are running dry sump but not as significantly as you might think.

if you are running anything bigger than -10 then you are spending money on stuff you don't need, carrying around weight you don't need to carry , adding complexity that is completely uneccessary and simply increasing the volume of oil that the system holds for no material benefit what so ever. and even -10 is a stretch in 90 % of the cases. there is absolutely no benefit or upside to running bigger lines that what mechanical requirements are.

you guys just LOVE all that stainless and anodize... its like boat viagra to you.

I would think the higher the pressure the more it would arierate the oil. like my BBC at 60psi vs one at 80-90psi.

A meling tech told me that their hp pumps have the bypass (spring)set at 75psi.I wonder how much is bypassing all the time ?

Nice post steve!

the trick is to not by pass any. amd now that you mention melling, THAT's where i saw that video... not federal mogul... but to answer you...

you want the oil system to work as efficiently as possible for all the reasons that are obvious. over pumping costs power, areates the oil, makes heat , wears out your distributor gear... on and on. thats why these hi volume oil pumps are not necessarilly always the right answer. more isn't better. whats " right" is better. you only need an oil pump big enough (in theory) to supply the volume of oil necessary to service the clearences while maintaining the correct oil pressure required to service the loads. no one is asking anyone to figure this out. the engineers have already done that for every conventional v-8 made which covers about 97 % of the motors that are discussed here. normal architecture, normal revs, normal clearences and normal loads. use a std oil pump with std filters and coolers and lines. the oil by passes a bit when its cold and stabilizes at service pressure when its hot and the motor will stay alive forever.

add a blower or a lot of compression ratio and a lot of revs and maybe now instead of a service oil pressure of 45 psi you need 60 because the unit loading on the bearings is that much greater... maybe... each combination is different but either way, the lines themselves are seldom if ever any sort of variable. thats one reason why dry sumps are such a good deal. you tailor the rotor size on the inlet to put in only the volume ( which turns into pressure when it runs up against the bearing clearences ) that you need to support your loads. no over pumping minimal by passing.

my point ( as long winded as it turns out to be) is that unless you are materially changing the loadings in the motors either by revs or compression ratio or sustained wot like racing requires, the chances of you needing some sort of extra ordinary non standard oil system is extremely unlikely and in a majority of the posts that ask these questions, it is someone with box stock hardware trying ( in good faith) to make it better. the engineers that put this stuff together and the factorys that produce it are clever clever smart guys. they have an enormous amount invested and riding on what goes out the door. do yourself a favor... every time you look at something that you want to make "better" just make sure that you aren't wasting your time and money fixing something that isn't broken. i know its great fun customizing and all the shiny stuff is a great turn on but in reality, there is precious few direct replacement products in the aftermarket that are any better than the stuff that the factory gave you in the first place.

msd being the most obvious example.