Working in the pump industry and dealing with questions of flow rates and friction loss i can tell you guys that there are way too many variables in every single application that there is no "standard" in just about ANY case....you can have two nearly identical setups and have different flow rates and pressures. On boats it gets crazy trying to determine the flow rates when you don't know how deep the pickup is in the water.....or for that matter what type of pickup it actually it...clam shell, a cut tube, a NACA duct grafted in to the bottom....hell even the rocker in the hulls bottom changes flow rates!!! Then you get into the pipe/tubing...is it smooth walled, is it reinforced...then we get into fittings....are they hard 90's or smooth bend 90*....then you have "T" fittings, valves etc....then you have sea strainers and how much they can flow...and pray they are not clogged with anything!

The one thing reading MILDS post about them "requiring" 15-20psi at the cooler....first thing that came to my mind is if the boat cant go fast enough to ram enough water through the system to generate the 15-20 psi.... and the owner then restricts the outlets of the chiller to get the "required" 15-20psi, they have in fact just cut the flow rate of the liquid going through the chiller and will it still cool properly??? And i also wonder what kind of IAT's will result by doing this?

When it comes down to it....someone's investing thousands into a blower motor, they should not be overlooking buying a few extra $50 gauges to make sure your investment is operating properly! ;)

I had a flow curve of the mercruiser seawater pump we tested here about 13 some odd years ago i'm going to try and find...if not i think we may need to re-test one again! :D but i do remember it was able to generate almost 50psi when we started to dead head the pump

Wally mentions a good point about fittings. I recently saw some data on a forged 90* fitting, vs a full flow 90* fitting. I always knew full flow 90s flowed better, but the difference was way more than i expected!

Yep, when we speck our pumps for customers we always add a min of 2' of head height restriction per fitting in the system....(most of the time these rocket scientists don't know what their system setup is exactly anyway so we just cover out butts) But if you even take a full flow 1" valve and compare it to any standard off the shelf valve and you will be shocked...you would think that a 1" valve is going to have a true 1" flow through as the pipe your connecting to will have an ID of 1.049 on a sched 40 pvc or a .957 on a HD pipe.....but the valves i've seen can be as small as .750!! And that right there is a choking point!

I think I remember you doing that on Slowwake, and remember saving it. But that's many computers ago. If you could find that info again alot of us would love you for it ! LOL. How many opportunities would any of us be able to test it ourselves ? Near none.

I remember at the same time, this is a definite, I pegged 60psi water psi with a Bravo sea water pump on the dyno. That ended being one of a number of small disasters. LOL.

I agree.

Easy way to remember it, is that it flows off psi differential..just like air. Imagine if our intake ports had to deal with 90* angles. Ouch !

Mentioned this on another site, and it's a funny but true , I hand ported (see, funny) my stream last night.:readinghelp::lolhit: It was having some flow issues with our recent rain. A few obstructions formed (collected) at some 90's and near 90's. Straightened that out and Flow is way up now...water back up is not an issue anymore.

Well i cant find it as we too have changed computers a few times as well....but here's a peek at my test lab
1100 gall water tank
1&3 phase power supply we can vary voltage and frequency
and sensors that can read motor rpm, and motor torque, GPM, psi/head height, temps of motor and water exiting if need be and efficiency when we graph it out if need be

Ran it on dyno. Only was able to hook up a garden hose to the core due to time constaints and what we had on hand. Ran 5/8 hose in, 5/8 hose out with 5psi in core. Inlet water temp was about 66 degrees. Intake temps with blower at 1:1 making 6psi, were about 95 degrees at 6000rpm. Ran blower at 10% over, making 8psi, intake temps went to about 105 at 6000rpm. 420 roots B&M blower.

what are the hp&torque numbers?disregard,i just looked at the other thread.

it made 818hp and around 700ft lbs.

Hard to compare to my old setup though I think. Running sea pump, alternator, and 1 7/8 headers thru 4" tails, vs 2.25 headers pretty much no tailpipes.

I did have to add a bunch of fuel to get the AFR's where I wanted them. Last time it made 800HP with 82/92 jets and 7lbs boost. This time, it made the power, with 96/100 jets in the same carbs and 8lbs. I did drop from 9:1 to 8:1 static as well.

I guess we will have to see what the speedo says when I get them back in to see if I gained anything.