Plumbing my chiller ?

[1968Droptop]

Here's my plan for plumbing, opinions welcome.
Currently water comes into the engine through the water pump block off plate, out t-stat housing (I am running a 160* t-stat). One exit line goes to right side Lightning header, the other to the other header.
Now I plan on running the inlet to the engine as b/4, but both exiting lines from the t-stat housing are going to dump through the transom. I plan on tapping into the other side of the pump for water inlet to the chiller, then exiting the chiller to a 'T', and from there to each header. Figured it'd be colder water running through the the headers which would be a good thing (?).
My intake manifold has a real large upside down 'V' inside (BBF), no areas for fuel to puddle. I read that someone here had water runnign through the chiller all the time with no adverse affects, and he had a similar intake to mine. Do I need to limit the water pressure going through the chiller ? THANKS as always for your input !

[YeLLowBoaT]

just plumb a water pick up, to a "sea strainer", to the chiller and a dump overboard for the exit. you really don't want to have water flowing thru at idle... condensation is a bad thing in the take manafold.

[Warp Factor]

Don't worry about condensation. With the pressure drop across the throttle blades at idle on a normally aspirated motor, the air is probably already colder than lakewater temp, even in Washington, and they don't seem to have problems with condensation.

[Boostedballs]

I wouldn't be too worried about condensation unless you have to richen up your idle while the water is flowing. If you do have fuel separation issues at idle, I would consider using an electric valve downstream of the cooler that lets water flow as soon as your intake is over ambient pressure. It may sound silly but most lawn sprinkler systems use some robust 12vdc valves and there are even some in cars for the heater lines. Hook this to a 2psi hobbs switch and you'll be in business. I would not let the cooler run dry while the engine is running. It may be possible to install the valve in such a way that the cooler stays full even if the water isn't flowing. This will give you a split second for the stagnant water in the cooler to absorb some heat before the water starts flowing. You don't want cold water to shock the hot cooer and crack your solder joints, hydrolock engine, etc$$$.
Another idea might be to use a ShurFlo pump downstream of the cooler. you can prime it before starting the engine to fill the cooler. The water won't flow out of the pump on its own and those pumps can prime themselves quite a ways above the water line. This way, you will have the water sitting in the cooler until you stomp the gas and a Hobbs switch closes and starts the pump. The Hobbs switches can handle the pump load without a relay. Hobbs switches can be found at Napa for about $15.
*The shurflow pumps are NOT coast guard approved for closed engine bays.
*I would not let the cooler see over 15psi

[1968Droptop]

Thanks for all the tips guys ! I think the KISS way is to use my jet pump to move the water through the cooler. Then at least water will be flowing at all times the engine is running. Great tips about the delay in water, and the shock effect on the exchanger going from hot to cold in a hurry.
I'm going to purchase another pressure relief valve (currently using one on the engine) for the chiller. I think I'll also install a water pressure gauge to monitor what's going through the chiller. The pressure relief valve on my engine runs around 2 pounds of water pressure at idle, which seems to be plenty to keep the engine cool, even after long idling periods. It tops out at or about 14 pounds. From what your teling me, those numbers sound just about right for the chiller.

[cave]

1968Droptop I asked this a while back and got some great advice from some of the same players in this thread. Check it out. You posted comment #6:D
http://www.***boat.com/forums/showthread.php?t=159749