rickb

Did some searching and see mixed responses. Don't know why I'd expect anything more definitive, but here goes

Do I _need_ to run an external water pump and thru hull water intake to keep a mild 454 (400 HP) happy when converting to FULL closed cooling?

Some of the kits claim they run a larger HX to make up for lower water flow.

Would like the simplicity of not running the external pump if possible.

I know the alpha still needs water pickup to cool the oil/gears.

Rick

cuda

I have a full closed cooling system on an SBC run on the regular Alpha pump. I haven't had any trouble with it not cooling, though I was told I might. The Alpha I bought did not have an impeller in the drive, so it was obviously run on an external raw water pump. I don't think if you ran an external pump you would have to worry about running the normal water through the outdrive, that small line carrying the water doesn't amount to a hill of beans as far as cooling the drive, compared to the whole leg of the drive already being totally imersed in water. If you worried about cooling the drive itself, I'd put a drive shower on it.

rickb

Good data point. I think I found another of your posts on my search. I have a little more cubes, iron and HP to cool!

Where do drive showers feed from?

Iggy

Drive showers feed from the water pressure created as you ride along. They attach, or drill through, the cavitation plate and have pickups hanging down into the water behind the prop. The prop wash will force water up through the shower.
Some people who have Alpha drives and converted to an external water pump have used the internal pump to feed a drive shower.

markf

Let me add a little more to the mix... When converting to FWC on a BBC with and Alpha and selecting a transom speed pickup for water will the pump pick up enough water at idle or during extended idle at the dock?

Has anyone plumbed the water pickup from the Alpha and a transom pick-up through a 'Y' to the raw waterpump? - overkill?

thanks
Mark