Thread:

jet boat plumbing question

its time to do some plumbing on the tahiti and i have found quite a few diagrams of what goes where but i am still short one answer. im running rewarder OT water fed headers, does the water need to be heated before it enters the block as it does with water jacketed exhaust? if so, how does that work into the plumbing setup?

Nate

With headers, you will not be running pre heated water to the block. Straight from the pump with a valve to regulate flow into the block, dump overboard and to headers above 2000 rpm +/-

Originally Posted by 67weiman

With headers, you will not be running pre heated water to the block. Straight from the pump with a valve to regulate flow into the block, dump overboard and to headers above 2000 rpm +/-

cool. sounds a lot easier than i had anticipated. is there a certain temp of water i should be staying out of since there will be cold water going into a hot block?

Originally Posted by 67weiman

With headers, you will not be running pre heated water to the block. Straight from the pump with a valve to regulate flow into the block, dump overboard and to headers above 2000 rpm +/-

also what do you mean by dumping the water above 2000rpm? i know it sounds like a stupid question but i just dont wanna blow the motor on day one.

The water going into the headers is regulated with a Bassett T-valve that has a ball & spring in it. When water pressure overcomes the spring, it sends water into the headers at around 2000 RPM. Water will shut off under 2000 RPM or idle to prevent water being sucked into the exaust valves due to reversion.

Okay makes sense. I'll be starting on it in a few days hopefully so I'll let you guys know how it turns out. Thanks for the help. Appreciated as always

I think that ive got the plumbing figured out for the most part. Only question now is that i already have a gate valve coming off of the bowl....do i need another one for the dump or can the one off of the bowl act as the regulator for the t-valve?

bump

You will have to run it and see. It all depends on if it builds enough pressure to open the spring in the t valve. If not then you will have to restrict it on the outlet too. Last year when i was running headers and switched my outlets to twice the size of my inlet I couldnt build enough pressure to open the t valve, but before when my outlet was the same size it worked but put too much water through them because I had too much water pressure.

kinda figured it was a test and tune thing. works for me...just means i get to put it on the water Ive been doing some research for plumbing and it seems like there are a few different routes i can go(ie-thermostat/t-valve/banderlog) Is this correct and if so, what are the pros and cons to them?

Lots of different opinions on what works best. Many prior threads explain different options. Main thing is that you don't want any water/steam coming out your pipes at idle & when you are cruising there should only be a mist, not a garden hose of water, coming out the pipes.

I run lines to under the seat with a gate valve for manual shut off before the Bassett T-valve. Same thing as the Banderlog valve but manual. More piece of mind. If I forget, the T-valve is still there working. I have had a spring break in the T-valve.