Hello all.
Rigging the boat and I don't have any room to install a "T" for my water pressure blow off valve between the strainer/heat exchanger and the crossover. Not possible to install it in the intake as it's fully occupied.

Question is:
Can the relief valve be before the heat exchanger?
My pressure gauge is mechanical and in the intake manifold water jacket, so I can monitor the internal / block pressure and adjust the blowoff to maintain that.

I'm thinking that it doesn't really matter where I relieve the pressure, just as long as I do so to maintain my system pressure at 20 pounds or so.

Thoughts please.

I can't see why it would make a difference, you will just have to play with it to find out where you achieve your desired pressure due to any head loss.

Edit ; I should add as long as you have enough flow thru the engine and headers .

i put a tee in just after the oil cooler before the engine set it for 20lbs

That was the plan, but there isn't enough room for me to do that. Thus the question as to if it matters if it's after the strainer, butbefore the cooler

object for me was to flow water volume thru the cooler but a lot of people do it at the strainer

Personally, I would run the boat without it first, and see if you actually need it.

Like mentioned, you could put it before the cooler, but you would be leaving some cooling capacity on the table by not dumping it after the cooler.

That should work fine and there should still be plenty of water flow through the oil cooler.

Rob, are you running transom mounted pickup? If so, here's how I would go about it. Whether or not its the right way, I dont know.

Anyhow, I would mount the pickup on the deep side, and go run the boat. Then trim the pickup down, until you get your desired water pressure. IMO, a relief valve, should be there to prevent damage from "spikes'' in rough water, not to use as a full time psi regulating device.

With that being said, my boat has never had, nor needed "pop off valves". With my setup, its usually in the 12-20 psi range depending on speed. If my pressure was say, 50psi, I would be trimming my pickups, rather than scooping the extra water, only to dump it back overboard again.