Always good thinking ahead. What is max psi on chillers? Glad to see you putting relief valve on. Anything from here on out I am running also. Even without chillers. To much water pressure not good on anything.

I run 2 of them, turned all the way out still have 23 psi, can't get mine any lower.

Do you have them plumbed before or after the chillers ?

After? What would that accomplish?

Not sure of the max pressure. I think 25-30 is max. I don't run one on the engine but I'm using a merc single stage pump (this time). That's what comes on stock motors so I didn't really see a need. Last year I ran a 2 stage pump and wasn't getting any more than 7-8 psi in the engine or chiller. Never ran warm tho. In fact it ran cold and I had to do an oil thermostat. Still took 45 mins at 3500 rpm to get oil temp to 180. Water temp is always 145ish

Benjen....people seem to have different opinions on where the relief valve should go but why does it matter? If the relief valve is after the cooler would the pressure be that much different before the cooler? I would think that the pressure would be similar throughout. Also Hardin marine sells a thru hull fitting/dump that is also a pressure relief valve all in one. That would obviously place the valve way after the cooler. I'm certainly no engineer tho

I don't know what to say. Maybe it's me/my boat. After the chiller in my boat, and I thought everybodies boat, but maybe not, the water dumps overboard. So, what pupose would the regulator serve than. Plus isn't the concern about the pressure in the chiller core? Which again what purpose would the regulator be exiting the chiller?

I have no idea either. I have the Teague plumbing diagram that someone shared with me on this site and I'm following that(sorta). So I'm putting mine on one of the water intake ports....so before the chiller as well. A lot of it doesn't make sense to me. I just hope it all works because I'm broke now

I would assume that there would be some pressure drop across the chiller, so after the chiller could be set at 20 psi, but the input pressure may be higher. My boat didn't have them, but if I had added them, in front of the coolers for sure.

You own a boat...........so of course your broke.