Question about transom water pickup installation
 

I have a couple of questions about installing transom water pickups. I am installing them on my 1988 Cigarette 31 Bullet so the boat has a straight hull with no steps. I searched here on the board as well as other places online and it seems that some mount the pickups straight up and down while others mount them at an angle to match the angle of the bottom of the hull. I am sure both ways work but is one better than the other? I have the Hardin adjustable pickups so I will be able to fine tune them, but is there a recommended starting point on how much they should extend past the bottom of the transom? Thanks!

What are you using them for ? engine cooling, intercoolers ect.

Sorry I should have included that info. They will be for engine cooling. Thanks

What Hardin pick-ups were you thinking about , because i bought a pair 4years ago and on the first trip out I broke the small weld on one of the adjustment bands and lost part of the pick-up

I mounted mine straight down because i did not want them to
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inter fear with the drain plug

Mine are at an angle, so the pickups are perpendicular to the hull bottom. Flush with hull at the transom, angled down to 3/16” maybe 1/4 below at the rear. My boat is under 70mph so no water pressure issues



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Probably don’t want them extending past the bottom of the hull. Maybe level or up a little. The water curls up when it’s past the boat.

The depth of the pick-up is going to depend on the boat bottom and water needs . When I first set my pick-ups in place there were a1/8in below the bottom that gave me 15lbs of pressure at 96mph , then when I added my 2 stage water pumps and inter coolers I could only get 5 to 7lbs of water pressure , I had welded my pick-ups and were no longer adjustable so I fish mouthed the hull right in front of the pick-ups and was able to get my pressure back.

Probably not that critical for a single stage pump. However, as the previous post indicated, as you increase your pump capacity you may need to increase the supply.
These homemade ones are feeding three stage pumps that serves oil coolers, heat exch, and intercoolers separate
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ly so they are oversized and flush in the leading edge with the trailing edge 3/16” low.