Oil flow with -6 vs -8 lines...

[carnut169]

I've got a stock 07 GSXR and am using the ports the bike uses for the oil cooler. George did the mod which forces all of the oil through the cooler. On the 04 dry-sumped motor I ran, we used -6 lines to a Setrab (sp-?) type cooler so on this motor I used the same...

On the way back from the Mitty a couple buddies suggested that the lines are not going to be large enough. I'm a bit confused as the adapters coming from and going to the engine are about -6 size, but they said I should be running at least -8, maybe even -10 lines.

The question is are the -6 lines going to cut it, or should I upgrade the whole enchalada to a larger size even though the ports are about that size?

Thanks!!

(oh, btw, I am running two oil coolers- the flow is out the right side of the motor into the right side cooler (bottom) then out the top of that and into the left side bottom, then out the top and back into the engine)

[RobLav]

I'm debating this right now too Sean. My dry sump for the Yamaha came with -12 fittings, and my dry sump tank (which ran a Kawasaki 1200) came with -10 lines. I'm debating where to put the -12 to -10 reducers - at the tank or at the pump fittings?

So my dilemma is to run either -10 or -12 lines.

And I've decided to run a fairly large oil cooler in the right sidepod.

[sidney]

As a failed hydraulic engineer turned marketing guy, myabe I can add some insight.

A 0.25" hose 24" has a pressure drop of 500 psi at a fixed flow rate and viscosity (22.4 GPM and 20 cSt). If you double the diameter of the hose to 0.5" and keep the same length, flow and viscosity, you get a pressure drop of 32 psi. Obviously, any pressure drop (line loss) you have results in more heat being generated.

You need to "weigh" the negatives of a larger hose (less flexible, more mass, bigger fittings, etc.) against the pressure drop you get with the smaller hose. For a fixed flow rate I can tell you the exact difference between the two if you know the flow rate. As with many other things, bigger is generally better.

Another important point is fittings. These cause all types of restriction. Basically, use jump fittings if you have a small port and you want to run bigger hoses. For our low pressure levels, you can also bore out the center of the fitting to reduce the drop. Running two coolers in series will make reducing the line losses even more important.

[glenn cooper]

Hi Brands,
FIVE HUBDRED? pressure drop in psi over 24" length? Typo?
I get and agree w/ Sean, the ports coming out of the engine crankcase are tiny. Going with a much larger hose diameter does not seem logical (again - untrained mind here).

I've even begun to wonder about other things, such as:
Is the stock GSXR oil pump up to the task of pumping all this fluid, fairly far, AND still provide adequate oil pressure?

Has someone come up with an external pump to use w/ the 'zook pump, kind of a booster pump? If not, can it be done? Affordably?

GC

[sidney]

500 psi is correct. Keep in mind, that drop is at 22+ GPM. We probably only have 2-3 GPM being pumped around our system, but this is a fixed displacement pump. The higher you rev the engine, the more flow you produce. You get more pressure drop at higher rpms and the oil spends less dwell time in the cooler, thus reducing the cooling effect. Now you get a little of that back, because the air is flowing faster across the cooler. Line losses add up quickly.

As a simple test, take a length of garden hose and blow through it as hard as you can. Now take a piece of breather hose of equal length and repeat. You will notice that it is much easier with the garden hose, because the drop is significantly less. Now air is a compressable fluid, so it's not quite apples to apples with our hydraulic system, but for demonstration purposes, it will suffice. Now I'm starting to sound like my old fuild dynamics professor.