I would plumb it with a seperate pickup that just force feeds the intercooler. That is how I do them all. I never take water from the engine....it needs all it can get.
It took an entire year to work out low water pressure feeding the engines. The boat is dialed in for the next owner.
Last edited by aTX427; 02-20-2010 at 12:17 PM.
[QUOTE=aTX427;3035621 It took an entire year to work out low water pressure feeding the engines. Should have the boat dialed in for the next owner.[/QUOTE]
LOL ... isn't that the truth.
Merc definately screwed the pooch on the cooling for the 600's and the 700's.
They basically took the watering system for a 525, and then added a little water hose off the power steering cooler to feed the innercooler.
When they realized that this was robbing too much water from the heat exchanger, they restricted the flow to the innercooler. -- this makes the innercooler MUCH less effective.
They should have installed a seperate pickup for the innercooler from the get-go and left the rest of the system as is! -- Dustin told them this when he designed these engine packages.
Its not hard to improve upon stupidity
The 850 and 1075 have a completely different raw water pump assembly. They don't need an external pickup because the pump has a pump stage for the engine and a stage for the intercooler.
How is that different though? I would think it would rob water from the engine in a similar manner.
Merc 850 and up motors use thru-hull or transom water pickups to feed the motor because #6 drives do not have water pickup provisions. They usually have one pickup per motor, with a multi-stage pump on the motor to feed the motor, exhaust, and innercooler. This type of pickup supplies MUCH more water than does the thru-drive style pickups that both the 600sci and 700sci use.
On Merc 600 or 700 motors, a single thru-hull or transom mounted pickup could be used in conjunction with a two stage pump to feed the motor water circut and innercooler.
This would be a somewhat involved process because the integrated fuel pump would have to be removed being that it is integrated into the stock raw water pump on the motor. A seperate off engine, fuel pump would have to be installed, along with an new dual stage raw water pump.
I personally like to continue using the outdrive to supply the motor water, and then add an additonal water pickup and strainer to feed the innercooler. Due to the reduced volume needed to just feed the innercooler, pickup depth and/or size can be reduced, thus only adding minimal drag to the boat. Innercoolers are typically fed of an an-12 (3/4") sized line.
Hope this helps,
Last edited by CB-BLR; 02-01-2010 at 12:02 AM.
Fountains are actually rigged with 700's, NtX transoms, #6 drives and 1.25" offshore pickups from the factory, which works so well that they install pop off valves to bleed off excess water pressure.
Last edited by aTX427; 02-20-2010 at 12:19 PM.
I would like to see the pull on another DYNO, these are not the same results we see.
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