This question is kind of for thought.
I am building a surface drive boat, Glastron hull with a GM L-92, the alloy block 6.2. intended use as a lake boat.
Image for thought,


Question at hand, can or will a decent sea water pickup with a 1 1/4 or 1 1/2 tube feed into the factory engine waterpump be sufficient for cooling flow? I intend a gentle ramp like a NACA duct inlet.
When underway I expect decent feed pressure. Just not sure if the impeller pump will self prime.
Thoughts?

Regards,
Charlie North

The circulating pump will not pull water. I doubt it will work. Maybe underway but not anything low speed.

I have a SS pickup from my skater I never used, I'll need to measure but think it's 1" ID or more. msg with email and can send photo & spec.

I recognize they are circulating pumps, but they can collapse a lower hose and burst uppers. Other causes for these failures as well, I recognize that.
This hull will have the intake formed into the pad, it will be a shallow angle ramp starting under the transmission. Essentially where the jet pump intake was.
I removed the original jet intake portion of the hull allowing me allot of freedom.

I think the only possible way it would work as if the the circulating pump
inlet was far enough below the water line to provide a constant feed to it,
they don’t develop suction to pull water in.

My estimate the pump will be a few inches above WL when stationary. This judging from my current CAD drawing of the project.
My mind is wandering to a possible test, drill motor on pump shaft and pickup hose in a pail. Granted an idling engine has allot more torque than a drill motor but I could chuck the shaft on the lathe. Heck I might see if I can get my hands on a new style pump and test this.

The circulating pump will not pull water up from below the hull. Without head pressure they will not move water. If it would, then a boat with a smoked impeller in the raw water pump would still run cool.

Your idea is interesting but The problem is your circulating pump is designed to do just that. Circulate.

it does not have the much more intense power needed to lift air and then purge it. Lifting water… without a purged line (once air is in the line) requires immense force, generates heat and is an issue….or so I was told.
Now… could you find a way to have the circulating pump pull from an onboard holding tank filled by gravity? Or have an electric pump involved? I also know guys who did the alpha drive solely for this reason but I much prefer the bravo.

but here’s how I did my LS swap

marineenginedepot.com

johnson F6b-9 crank mounted water pump (Amazon I think?)
Crank bolt adapter for LS sku 512601- I was really bummed by this. I designed it to mill and found someone else beat me to it
mount bracket sku 302391
mount bracket bushing sku 527018

it moves an immense amount of water… I have it in a 25ish gallon container and it drains it quickly at high rpm’s…

Mine is setup for closed cooling in saltwater. I have a clamshell inlet, strainer, and into my raw water pump and through my PS cooler, Oil Cooler, and my heat exhanger. I have all those part numbers and vendors for my LS as well just pm me if needed.

Here’s a link to my build idling. Hit me up if you need any info. Took lots and lots of research for this. Best of luck and look forward to what you end up with.
I can’t wait to run my v8 next to all these silent 4 strokes at the ramp…

Seventeen people have noted how and why it won't work....yet the O.P. is hell-bent to MAKE it work, lol! Simply has ZERO understanding of basic physics.

Apparently my recent post from this morning is not here or not been read, I am going to use a sea water pump. I asked a question, I received very good replies, I have a rather long reply composed and ready to send but have just learned a long time friend was hauled to the hospital last night distracting me from posting. So Take your BS attitude elsewhere.