Im looking for ideas on plumbing my intercoolers what works best force feed or plumbed trough sea pump I have heard of so many ways just looking for the best, dont want to burn down the motors thanks.

If you have a cross over tube insted of a circulating pump. They usually tap it in the cross over tube. I have a thru transom Water pickup for my water supply. So I use the outdrive pickup to supply my intercooler. Water flows once I'm on plane. you don't need water flow thru the intercooler at idle speeds.
Just remember. the colder the water the better.

I use one seperate unit on each side of the transom to supply the coolers

Thanks guys for the reply I have seperate pick-ups for the intercoolers now and I am relying on them to be force feed but dont seem to be getting near enough water flow through the intercoolers, trying to see if there is a better way of plumbing them to get better flow dont no if I should plumb them in to my sea pumps or not I no you dont want water flow at idle any info appreciated

What is your pickup configuration? Through hull or through transom? Is the leading edge of the pickup flush with the bottom? The trailing edge should be about 3/8" below the transom. My leading edge was down about 1/4" and I had trouble getting flow. I ground it flush and now I get flow out of the discharge at about 50 mph.

Craig

Not that it makes a lot of difference, but what intercooler/blower are you running. If you have roots type, with intercooler below carb/blower, route water intake line into lower rear of cooler, and out of top front. I always liked the separate pick-up that forces water into cooler when boat is on plane.
steve

Sorry I guess I should of said what my setup was 556ci BDS 871 on a superchiller, pickup is on the transom, I do have about 3/8 below on the trailing edge front is flush what kind of pressure should I see and when should it start picking up water speed? RPM? thanks............John.

The PFM Superchiller wants a maximum pressure of 15 psi at WOT. Make sure there are no restrictions in the discharge hose or outlet. The pressure will vary with speed.

Just an FYI, I have the same setup as you, intercooler wise. I installed a pressure gauge and watched with increasing speed. Also have a ball valve right after the pickup at the transom. Never could see much pressure. Kept opening valve slowly. Finally I realized that pressure seemed to rise almost exponentially with speed. Saw next to nothing at 60mph. Saw a couple of pounds at 80mph and blew a hose off at wot. My fault, used push lock fittings with regular heater hose and no clamps-didn't think there would be that much pressure. Probably had 20 pounds. All I'm saying is that you need to look at pressure at wot.

When using transom pickups I have run a #4 hose from a hot water source (one of the plugs on the water passage at the front of the intake manifold) to the outlet side of the intercooler. When idling around there is no pressure at the pickup and the small amount of warm water will run backwards down and out the pickup. The trickle of warm water seems to help the idle, and depending on your inlet location (high or low)will keep the core full of water. The Superchiller is more durable than the Lee units. It is almost impossible to melt a core if it is full of water, but when empty they are pretty fragile.

Once on plane the volume and pressure of the water from the pickup overcomes the small volume of warm water.

It has been a while since I did one like that, I can't remember if it needed any check valves or not. It has always been important to me to have a way to verify flow through the cooler. Measuring intake manifold temp is not a bad idea. A pickup clogged with sea weed is a lousy way to lose an engine.