Performance Boats Forum banner

1 - 20 of 50 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1
For starters, I'm a little new to this jet boat thing. I've got a Spectra mini day cruiser thats getting a fresh 460 engine which should be in the low 400 hp range. Its got a Berkeley E pump with an A cut impellar that has also been gone through. I've already installed a gate valve on the water line directly from the pump but was wondering if I should run a pressure relief valve as well? Will I see pressures high enough to worry about blowing a gasket with a stock pump setup? Thanks in advance for any advice.
 

·
The Man
Joined
·
1,788 Posts
For starters, I'm a little new to this jet boat thing. I've got a Spectra mini day cruiser thats getting a fresh 460 engine which should be in the low 400 hp range. Its got a Berkeley E pump with an A cut impellar that has also been gone through. I've already installed a gate valve on the water line directly from the pump but was wondering if I should run a pressure relief valve as well? Will I see pressures high enough to worry about blowing a gasket with a stock pump setup? Thanks in advance for any advice.
It's always a good idea to have one. I currently don't, but really need to get one on the boat. The pump can produce some high pressure spikes, more than the gaskets would see in automotive use.
 

·
Glendale Arizona
Joined
·
2,368 Posts
It's not really necessary, but not a bad idea. I ran my boat for years without and never had a problem. Lots of other guys have too. On the other hand, they're not that expensive and it's good insurance against excessive water pressure to the block.

When I bought the boat I'm running now, it came with one in the box of spare parts that came with it so I cut it in.
 

·
Registered
Joined
·
1,493 Posts
If you are concerned with it, put a valve on the water inlet, it can be simple as a water hose valve, but I like alot of others, on my thru transom exhaust motors, not required
 

·
Ain't Right Racin
Joined
·
1,706 Posts
I've never ran one. I feed with #8 to a T and #8 to each of the water pump ports and out of the intake with 2 #8's. I coud see a problem if u just had one outlet ike a thermostat pate set up. then if u ran a #16 out it should be fine.
 

·
Registered
Joined
·
354 Posts
I dont run one, or a valve of any kind. I did put a pressure gauge for the water on the top of the intake. @WOT it's 12psi. stock pump and stock motor.
 

·
Premium Member
Joined
·
5,115 Posts
I dont run one, or a valve of any kind. I did put a pressure gauge for the water on the top of the intake. @WOT it's 12psi. stock pump and stock motor.

How do you control ur engine temp without a valve??

I've never ran 1 and hadn't had any problems :cool:
 

·
Registered
Joined
·
939 Posts
pressure regulator

I run one. Originally I tried the gate valve direction. THen simplified by putting a pill in the connection between pump and engine. Figured I could choke off the single intake, with two exits. This would releive soem of the pressure. The issue I had was at idle, not enouph wter running through the block to cool it properly. Switched to pressure releif, and that has helped. You need to check that spring on a regular basis.

Jerry
 

·
Registered
Joined
·
8,169 Posts
In water......

I'll say it again, NEVER regulate the "in" water flow..... Pressure? Maybe, but do not restrict the flow to the engine.. EVER..... If the engine builds pressure that makes you nervous, add a dump line or two...You can regulate the "Exit" water to build heat, or more cooling, and remember, water can move too fast to take any heat with it..... The "in" hose/line from the pump should be larger than the hose after the split, ie: 3/4 off the pump, (2) 5/8ths after the "T", and 1/2" on the exits, or to the logs.... With wet headers I run two additional "dump" lines, one regulated on a cable controlled from the seat, one wide open..... In 3+ decades I have never regulated incoming water, or used a pressure relief/regulator on the "in" side..... Also, if engine gaskets fail under normal pump pressure they were inferior to begin with..... I always add a small bead of silicone around the water ports on the head gaskets, as well as intake to head water ports..... No leaks......
Ray
 

·
Living in a cage of fear
Joined
·
16,462 Posts
There is a difference between "having no problems" and maximizing performance/ efficiency.

I have ran the water straight in and out, with and without any valving, with and with out regulators/ relief dumps. With no real problems also.
(Well, except when a cheap hose connection failed on My first Miller and I came inches from sinking it)


This is what I have settled on over the years.

From pump to an overboard relief dump set at 12lb. (+-), this is hard lined with 1/2" pipe.
From there 1/2" hardline to a T with #12 to the engine, #8 to a header control valve at the driver seat.
The header control then goes back to the Basset T.

While I DO have gate valves between the pump and engine, they are ALWAYS wide open while running on the lake or river.
I ONLY restrict them for directing water when running on the hose.
I have a gate valve on the water OUT of the engine. (Dump line)

I will NEVER restrict water in, although I used to and many still do it to control temp. A telling tale is to install a temp gauge at the cyl. heads.
That sending unit on the intake manifold isn't going to say much if only steam is behind it.

By restricting the water out, in conjunction with the 12 lb relief dump, I can dial the engine temperature to virtually wherever I want it, never exceed 12lb pressure, and never risk air pockets in the engine.

With the manual header valve in the system, I do not have to worry about "balancing" the PSI for the Basset T either.

Again, there are countless ways that "work", but I like my engine to be at a happy temperature, not slugging along at 120* with "no problems".
It is different for me now, running a $10,000 engine with aluminum heads versus the old truck engine in my first boat.

The #1 concern for Me is parts or hose failure.
Tuning the water system or not tuning it is SECONDARY to having it as fail proof as possible.
Many people (Like I used to) almost consider it an afterthought and just rig up what they have for hoses and 25 cent hose clamps.
I have seen guys with pretty nice boats using plastic hose bibs and and old heater hose etc.
That's a great way to lose a boat.:no:
 

·
Living in a cage of fear
Joined
·
16,462 Posts
I dont worry about the engine temp unless I take it into cold water, always runs 160/175 depending in where we go.
Do you have a thermostat set up?


I am assuming so?

Also I see that you guys most likely have through transom exhaust on you cruisers, so they are sort of different animals than what i got.
 

·
Registered
Joined
·
6,573 Posts
I'll say it again, NEVER regulate the "in" water flow..... Pressure? Maybe, but do not restrict the flow to the engine.. EVER.....
and i'll say again - i completely disagree with this, always have, always will.

I will NEVER restrict water in, although I used to and many still do it to control temp. A telling tale is to install a temp gauge at the cyl. heads.
That sending unit on the intake manifold isn't going to say much if only steam is behind it.
one question. specifically, what is the exact pressure at your pump's cooling water exit at wot? exactly...

For starters, I'm a little new to this jet boat thing. I've got a Spectra mini day cruiser thats getting a fresh 460 engine which should be in the low 400 hp range. Its got a Berkeley E pump with an A cut impellar that has also been gone through. I've already installed a gate valve on the water line directly from the pump but was wondering if I should run a pressure relief valve as well? Will I see pressures high enough to worry about blowing a gasket with a stock pump setup? Thanks in advance for any advice.
in your application, you don't need to do any more than you've got.
 

·
Living in a cage of fear
Joined
·
16,462 Posts
one question. specifically, what is the exact pressure at your pump's cooling water exit at wot? exactly...
It is enough to keep the bypass open, I know that.



in your application, you don't need to do any more than you've got.
I would agree with this, as I said in my last post, 2 different animals.
 

·
Official Test Driver
Joined
·
863 Posts
For starters, I'm a little new to this jet boat thing. I've got a Spectra mini day cruiser thats getting a fresh 460 engine which should be in the low 400 hp range. Its got a Berkeley E pump with an A cut impellar that has also been gone through. I've already installed a gate valve on the water line directly from the pump but was wondering if I should run a pressure relief valve as well? Will I see pressures high enough to worry about blowing a gasket with a stock pump setup? Thanks in advance for any advice.
It does not hurt. It is nice to maintain your builders recommended water pressure by having one. We usually plumb them in and try to regulate 10-15 psi with a max spike pressure of 35. Others will just bypass water and not run a valve at all. Anyway- several options in brass, bronze and stainless steel. 😉


Sent from My Boostpower Marine Efi Beacon.
 

·
Registered
Joined
·
1,185 Posts
It's not really necessary, but not a bad idea. I ran my boat for years without and never had a problem. Lots of other guys have too. On the other hand, they're not that expensive and it's good insurance against excessive water pressure to the block.

When I bought the boat I'm running now, it came with one in the box of spare parts that came with it so I cut it in.
I really like how you rigged yours up.
So that ball valve is always wide open? Then does that pressure relief just dump the exess water pressure out?
water valve.jpg
 

·
Registered
Joined
·
7,464 Posts
Inexpensive "safeguard" (pressure bypass kit ) and has no down side to run one. We run our Lever ball valves at the jet wide open its only funtion, as far as I'm concerned is a shut off if a water line ruptures or were to come loose Tom
 

·
Living in a cage of fear
Joined
·
16,462 Posts
Inexpensive "safeguard" (pressure bypass kit ) and has no down side to run one. We run our Lever ball valves at the jet wide open its only funtion, as far as I'm concerned is a shut off if a water line ruptures or were to come loose Tom
Yep.
 

·
Registered
Joined
·
6,573 Posts
It is enough to keep the bypass open, I know that.
so you have a -8 coming from the pump to a T, a -8 from the T to the engine, and a -8 to your relief valve. the relieve valve lifts at 12 psi to an overboard dump. it is either open or closed (not a regulator). simple question that may seem obtuse to you, but i'll ask it anyway. do you believe that this 12 psi relief valve maintains the engine supply at 12 psi??
 
1 - 20 of 50 Posts
Top