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Magnum Ralph
04-07-2016, 03:53 PM
I purchased a Hardin crossover for my 406 to go on 94 18 with ss outdrive. They said ss pump will do the job. A friend who has been a performance boat mechanic for years says he doesn't like crossovers they provide inconsistent consistant cooling. What do you guys think?

Magnum Ralph
04-07-2016, 03:55 PM
Inconsistent cooling!!!!!!!

Magnum Ralph
04-07-2016, 03:55 PM
With bypass.

gcarter
04-07-2016, 06:05 PM
The Alpha/SS drive raw water pump doesn't have the capacity to operate effectively w/o a circ pump.
You can do it by doing the following:
Remove the pump impeller.
Remove the hose between the drive and the gimbal.
Block the water connection flange inside the gimbal/inside the hull.
Add a Stainless Marine transom pickup.
Add this crank driven raw water pump: http://www.marineexhaustmanifolds.com/raw-water-pumps.htm
Plumb the transom pickup to the crank driven raw water pump through all your various coolers.
This set up works very well, I've done it a number of times.

joseph m. hahnl
04-07-2016, 07:34 PM
I agree with George that the Alpha won't supply enough water. I wouldn't eliminate it though I would use it for the oil coolers and dedicate the new pickup/crank pump for block cooling. Or even better plumb the Alpha pump to be a drive shower:shades:

Magnum Ralph
04-07-2016, 08:04 PM
Is it worth it? That's $1000 in parts!!!

gcarter
04-07-2016, 08:29 PM
Is it worth it? That's $1000 in parts!!!

If you're in a HP race, you'll need more cooling. These are just building blocks.
But i think it's closer to $600.

Magnum Ralph
04-07-2016, 10:07 PM
Could you provide specific part numbers for pump and pickup sbc? Thanks !!!!!!!

gcarter
04-07-2016, 10:45 PM
The pump is a Johnson F6-B9 for $189.00 plus about $30 for a stabilizer.

The pickup is a



http://www.stainlessmarine.com/wp-content/uploads/2015/02/05-8888804-004-128x84.jpg (http://www.stainlessmarine.com/shop/1-14-npt-male-x-1-58-od-stainless-transom-mount-water-pick-up-ea/#)1 1/4″ N.P.T. Male X 1 5/8″ O.D. Stainless Transom Mount Water Pick Up


$229.00

1 1/4″ N.P.T. Male X 1 5/8″ O.D. Stainless Transom Mount Water Pick Up
Standard Transom mounted Water Pickup for larger gas or medium size diesel engines that do not run at high speeds.

Just Say N20
04-08-2016, 07:25 AM
Ralph,

I used the pickup pictured by George on my Donzi 16. That pickup has a pretty aggressive downward angle. I mounted mine with the leading edge just about flush with the bottom, and found the trailing edge was too deep (it made one of those fake looking rooster tails). Perhaps I mounted it too deep, but I seem to remember I did it according to their instructions.

I took a straight edge and held it flush against the bottom and drew a line on the side of the water pick up, and cut off the angled part so the outside part was ⅛" below the line I drew. It still had tremendous water flow, and had to be a marked improvement in drag reduction.

Remember that I had a Volvo drive, which does not contain a water pump like the Mercruisers do, so I already had a crank driven water pump.

What started this process was that I wanted a smoother drive, so I filled in the water pickups on the front of the Volvo 290, which had been the water source for the engine. With that source gone, I needed a new one, so I purchased the transom water pickup George pictured.

gcarter
04-08-2016, 09:00 AM
Ralph,

I used the pickup pictured by George on my Donzi 16. That pickup has a pretty aggressive downward angle. I mounted mine with the leading edge just about flush with the bottom, and found the trailing edge was too deep (it made one of those fake looking rooster tails). Perhaps I mounted it too deep, but I seem to remember I did it according to their instructions.

I took a straight edge and held it flush against the bottom and drew a line on the side of the water pick up, and cut off the angled part so the outside part was ⅛" below the line I drew. It still had tremendous water flow, and had to be a marked improvement in drag reduction.

Remember that I had a Volvo drive, which does not contain a water pump like the Mercruisers do, so I already had a crank driven water pump.

What started this process was that I wanted a smoother drive, so I filled in the water pickups on the front of the Volvo 290, which had been the water source for the engine. With that source gone, I needed a new one, so I purchased the transom water pickup George pictured.

Yes, sometimes adjustments are needed. But, as Bill said, start w/the pickup as it is supplied. On most larger boats, no adjustment is needed. On my TR, I have a water pressure gauge, and it registers about 6 PSI at 50 MPH.
Also, I don't recommend filling the drive water pickup on a Merc drive as water flow is needed in the upper gear box for cooling. Even w/o the pump impeller, plenty of water will flow through the drive. By removing the connecting hose, water will cool the drive and then dump back into the water.

Just Say N20
04-08-2016, 10:49 AM
Yes, sometimes adjustments are needed. But, as Bill said, start w/the pickup as it is supplied. On most larger boats, no adjustment is needed. On my TR, I have a water pressure gauge, and it registers about 6 PSI at 50 MPH.
Also, I don't recommend filling the drive water pickup on a Merc drive as water flow is needed in the upper gear box for cooling. Even w/o the pump impeller, plenty of water will flow through the drive. By removing the connecting hose, water will cool the drive and then dump back into the water.

Absolutely!

gcarter
04-08-2016, 05:50 PM
Ralph, here's a link to a thread which covers installing a transom pickup:

http://www.donzi.net/forums/showthread.php?49388-vonkamp-s-Barrel-Back-18