I am in the process of adding 3.8L Whipple's and have a question on cooling. I plan to add external pick ups plumbed into my water pump to feed the motors and plan to use the drive (IMCO SCX with SC lower) to feed the intercooler. My question is, will the IMCO supply enough water to the intercooler on its own or do I need to have a pump?

The IMCO lower should supply plenty of water at speed to keep the intercooler pressurized. You may even have to put a pressure regulator on it depending on your water pressure.

Im running SC lowers feeding two stage pumps -20 for transom to the strainer -20 to the pump then -12 to the intercooler and -16 to the engine thats all that is needed no transom pickups on mine.... Ive never done it without a pump

The SC lower will supply plenty of water. Pressure feeding, not fed through a pump is how Dustin Whipple suggest I plumbed my other boat when I put a 525 with whipple in.

I would suggest a sea or sand strainer with a pressure relief off of it so you’re not shoving too much through the intercooler

Thanks, that's what I was hoping for. I know Whipple is looking for specific pressures on the block, is that the case with the intercooler as well?

There are multiple ways to accomplish this without drilling extra holes in your boat......intercooler needs flow to cool the charge not so much pressure....where are you dumping the water ?

What others ways are you thinking other than 2 stage pumps? Intercoolers will dump out the side. Already holes there for them.

I had mine running through a two stage pump in my Baja that was fed from the scx lower. Wasn’t a stock 525 anymore but the motor didn’t like cold water constantly flowing through that very efficient intercooler. I ended up replacing two stage pump with single stage, rigging an in-line check valve from Teague, reduced the spring pressure so that it essentially was a check valve, so as soon as more water was being forced into the sea strainer than the pump could take and pressure built in the strainer it would then start feeding the intercooler. Depending on what prop I ran this would be 2500-3500rpm. Still running strong like that to this day.

yes, I was concerned with the colder temps at idle running thru the intercooler and keeping the motor too cold. Sounds like your "check valve" worked in your application. Thanks

I think pump vs no pump would depend on air and water temps you do most of your boating in, here in the Midwest it gets hot from June through September with temps in the upper 90's......jmo