-10 from pump to a t that splits into -8s going into water pump plate one -10 out of intake manifold to over board one -8from intake to header valve at drivers seat then obviously back to headers. No thermostat. I think theres just too much water for that relief valve to handle. So im guessing that gate valve will limit the water flow and let that valve work better and keep the engine temp up

Some pics from yesterday and a pic of relief valve setup


Sent from my iPhone using SoCalJetBoats

-10 from pump to a t that splits into -8s going into water pump plate one -10 out of intake manifold to over board one -8from intake to header valve at drivers seat then obviously back to headers. No thermostat. I think theres just too much water for that relief valve to handle. So im guessing that gate valve will limit the water flow and let that valve work better and keep the engine temp up

How large is the actual port in the dump line overboard fitting? The easiest way to measure it is with a drill index. It should be about 3/8" to 7/16". And since you are not using an automatic header valve, you should have a gate to regulate incoming flow. What valve do you have to control header water?

GT

Sent from my SGH-T989 using SoCalJetBoats mobile app

Its a rex marine valve for the headers. I also have the basset t but i use the rex valve just because inhabe a tall cam and dont waant to worry about reversion. And the dump fitting is a 1/2 npt to -10 adapter  so im guessing 7/16

You have two possible fixes.

The easiest is to install a gate valve.

The other is to install an aluminum plug in the pipe coming if the pump suction housing and drilling it out to 1/4". This will reduce the flow to very close to where you need to be, but be warned that it can plug fairly easily with debris and cause an overheat and you still can't shut off the water if a hose gets burnt/blown off.

The valve is more serviceable and adjustable, since you took the factory hose connector off the pump, there is too much water entering the engine. The original hose barb in the pump was 3/8"mpt x 5/8"hose and had a .230" hole in it, you now have a .375" hole and this is way to much water to try and deal with.

Go buy a Red and White threaded gate valve and be done with it. You will likely have to get a 1/2" valve and a couple of bushings, I use 3/4" valves.

Jmho

GT
Sent from my SGH-T989 using SoCalJetBoats mobile app

Gate valve worked pressure is about 10 while cruising and up to 15 at wot. Still milkshaked the oil tho. Only thing left is head gaskets right?

Tunnel ram dual carb

Wait don't pull heads what kind of intake are u running.


Sent from my iPhone using SoCalJetBoats mobile app

I just changed intake and timing cover gaskets. Used good felpro stuff

Pm sent


Sent from my iPhone using SoCalJetBoats mobile app

Ok that's fine I'm a 455 owner too had the same problem call me tommrow. I think your gate valve is open to much.


Sent from my iPhone using SoCalJetBoats mobile app

Hmm really? Ive got the pressure down to about 12psi according to the guage i put on the intake

Thats good Pressure inside your motor (You don't want more)  Is that WOT?

however with your Gate valve you still have too much water volume enterting your block if it is still mikshake inside your oil

A relief setup might be your next step if all else fails.  It worked for me

This is a hot topic and probly the most asked question your gonna get alot of opinions.

Now I can't get the damn thing to start to flush it with clean oil! Tried a new distributor cap. It starting doing this at the river. After I'd get it fired up it wouldn't be a problem but starting it cold took forever. Now it won't start at all in my driveway. Any ideas?

Its possible these carbs are freshly rebuilt but are a little "weathered". Had a few external fuel leaks when i first put them on. What was leaking on yours?