inspector747

iTrader: (3)

Getting ready to install my Cross over with Bypass (Hardin Marine) and my question is will I need a pressure relief inline as to not make a milkshake, and if so where do I install it?

Thanks
Bryan

stlliberator

iTrader: (1)

http://www.hardin-marine.com/p-13357...th-bypass.aspx

Is this the one you installed?
If so I just installed one on my 502...why would you need a pressure relief in the water lines??

1BIGJIM

iTrader: (1)

Yes you will need one. Also install a water pressure gauge. My valves are located right before the input to the cross over. I would buy the adjustable relief valve, not the expensive merc plastic one.

inspector747

iTrader: (3)

Yes that is the one I just installed (Hardin Marine), I am installing a pressure gauge to, only reason I'm considering adding a relief valve is my old crossover wasn't allowing me to run a T-stat and from what I have read there may be a chance of over pressurization, I'm going to order the one from Hardin as well (adjustable), I just wasn't sure the best place to locate it.

MILD THUNDER

iTrader: (3)

I have a crossover, no relief valves, and no water psi issues.

inspector747

iTrader: (3)

What kind of PSI are you seeing at WOT?

MILD THUNDER

iTrader: (3)

16-18psi at 85+mph.

People assume the crossover somehow adds pressure to the system. High water pressures can be from transom pickup variations, style, depth, etc. Or, restrictive flowing exhaust manifolds, or small water lines feeding manifolds, etc. Every boat is different.

Buddies 38 Cig, had high water psi. 25psi just cruising. would peg the psi gauge with hard running. The solution wasnt relief valves, it was trimming down the water pickups on the transom. They were too deep. A little goes a long way on that. Plus its scrubbing uneccessary speed off. I also recommend running dumps off the rear of the intake manifolds, at the water jacket on a siamese block like a 502. Helps cool those rear cylinders down, and can be used to fine tune the water psi by playing with hose size on them.

inspector747

iTrader: (3)

Having taken the boat out only once and realizing the current issues (no t-stat),this is great information that I will use, My previous crossover didn't a t-stat because if there was one installed the manifolds wouldn't see nay water until the t-stat opened, now I have that problem fixed but was/ am concerned with over pressurization but with the information you have given me I need to get it out on the water and see what is happening.
Thank you

stlliberator

iTrader: (1)

Ok..where do you pick up for the water pressure gauge?

inspector747

iTrader: (3)

Port side of the block I ran my line from there