Jet Boat cooling setup

[BrendellaJet]

Starting to plan the reassembly of my boat. Its been apart for far too long and a lot has changed since it was together last.
What size inlet hose do you recommend coming form the pump? I presume I should T that line before running water into the block.- If so, what size should these lines be? Ill be running OT headers with water injection, does it matter what size the exit line is? I have some 8 AN water dumps that i would like to use, will one of them be sufficcient to get all the water out or should I use 2?
Theoretical question-considering the amount of pressure a jet pump can generate, does it really matter what size output line is when I can just adjust the regulator up or down to control the input? Motor is a big HP N/A 548 and cooling will be an issue.

[sanger rat]

10 in 10 out. 8 to the headers. Run a pressure relief valve.

[ANY&ALL]

Went though a milkshake (water in the oil three times) before i final wised up rex marine themo kit 99 bucks comes with all the suff the pressure from the jet is a killer the kit has a bypass to keep the pressure down my motor with out it always ran 105-110 degrees now 160-180 i love it and nothing to adjust and is already setup for your water inj. ext. my two cents.

[BrendellaJet]

Engine builder says no go on the thermostat. Due to compression we are running block needs to stay cooler than normal.
Will a 10 in, 10 out design allow pressure to build up, seems like it wouldn't. School me please if Im wrong.

[RCB19]

With a motor like that you want to move lots of water through it. Especially if it is going to be a pump gasser. I would concentrate on water volume not pressure and keep it around 120*. Use a pressure regulating device before water enters the engine & set it at 25#. Minimum #10 in and out as said above. Let us know how that monster runs.

[BrendellaJet]

RCB, thanks for the advice. Im the guy that bought the water dumps from you. Thanks again. Hows the boat running? Back together yet?
Okay, that makes 2 that say 10 in, 10 out. How do I deliver the water to the block? I assumed the two inlets at the front of the block would both be used. Is that not the case? I was hoping to use one of my 8an fittings for the exit, can I use 2 or should I get a 10?

[Wicked Performance Boats]

My blown BBC has a #10 in from pump to the pressure regulator set at 25psi,#10 to a tee, 2each #8 to front of block, 2 each #8 from thermostat housing to overboard dumps. Off another intake port, I have a manual valve mounted between my legs to regulate water, #8 into Bassett tee/with no spring or ball, then to headers. I left those out because it makes so little pressure that the Bassett valve won't work! I just have to remember to shut it off at idle. I also tapped the #8 male to #8 male fitting at header lines with an 1/8th pipe tap and screwed in a brass pipe plug, then I drilled it with a .065 drill bit, makes a great water restrictor. Budlight ps. Actually I never turn the water on unless I see a COP!

[Cs19]

-10 from the jet with a regulator inline then to a "T" or "Y" fitting to 2 -8 lines entering the front of the block (water pump area).Then you will have 2 hoses coming out of the thermostat area. One will be a -10 and one will be a -6. Run the 10 overboard with a ball valve inline and the 6 up to a valve up by your seat to control water to the headers then back to a "T" or "Y" then to the headers.One other thing you might wanna do is weld up the brass fittings in the bassets and re-drill them to a much smaller ID.
Thats how mines set up, Im sure your engine builder wants something similar in yours.

[BAE_557]

This is the setup I used on my old Blown Alcohol BBC
http://www.hotboatpics.com/pics/data/3021/1870jet_plumbing_3.jpg

[BrendellaJet]

-10 from the jet with a regulator inline then to a "T" or "Y" fitting to 2 -8 lines entering the front of the block (water pump area).Then you will have 2 hoses coming out of the thermostat area. One will be a -10 and one will be a -6. Run the 10 overboard with a ball valve inline and the 6 up to a valve up by your seat to control water to the headers then back to a "T" or "Y" then to the headers.One other thing you might wanna do is weld up the brass fittings in the bassets and re-drill them to a much smaller ID.
Thats how mines set up, Im sure your engine builder wants something similar in yours.
Thanks man. That sounds good.

[tahitijet]

On mine i run 10 into a bypass set at 15lbs.. then an oil cooler to a T, -10 into each side of the front -10 out both sides of the thermostat ( just so it looks the same) 1 -10 overboard with a ball valve at the thru hull fitting and the other to a basset T with both sides reduced to -8 for the headers. I can idel all day long and never get over 140 on a run it drops down around 110-120

[RCB19]

[QUOTE=BrendellaJet]RCB, thanks for the advice. Im the guy that bought the water dumps from you. Thanks again. Hows the boat running? Back together yet?QUOTE]
Oh ya I remember ya. I finished rigging my Rogers a couple of months ago. Iv'e had the boat out several times and am very happy with the performance of it after all the changes I made to it last winter. Hopefully your questions were answered on the cooling lines. I set mine up with #10 from the pump through a pressure regulator, #10 out of the regulator into an oil cooler, #10 out of the cooler to a Y, #10's out of the Y into each side of the block, #8's out of the water divider into another Y, and then #10 out of that Y overboard. My header water is brought in by a Tee fitting that is placed on the outlet side of my oil cooler, through a small ball valve, to the Basset Tee & out to the headers If you can picture that..... The header water controll is all contained in the bilge area near a stringer. I set the ball valve once and leave it. I set it up this way to burry the ugly ass ball valve. All that is visible are stainless lines. Now get that Brendella back together! :D