water bypass kit

[jwbbuck]

http://www.hi-techperformance.com/ advertises a water bypass kit for jet for $150. What is it? I've already got a few valves to control the water pressure. Is the bypass kit better.

[lakecrazy]

I found a water bypass valve on the Carr-McMaster plumbing supply web site that looks exactly like the one Hi-Tech sells but with a much better price.
It is adjustable to 0-50 lbs water pressure and cost $35.00 Part # 9763K49
[This message has been edited by lakecrazy (edited February 20, 2002).]
[This message has been edited by lakecrazy (edited February 20, 2002).]

[Hydro-Thunder]

lakecrazy is right you can find a relief valve like that at any plumbing shop.

[Q-ball]

I was wondering the same thing. Do the two gate valves I have plumbed in save my gaskets from getting too much water pressure from the jet, or should I ALSO be running a bypass system?

[Unchained]

I would say that the bypass valve is more important than the gate valves even thought I use both. Here's a pic of my setup again.
http://www.childsdale-ind-prop.com/jetpump.jpg
Contrary to what some think the bypass is not a restriction in the line. The water can flow right past it as you can see in the pic. It just dumps the excess to maintain the water pressure you set it at.

[Wet Dream]

Unchained,
It looks like the valve dumps the excess towards the place, correct? But it also looks like you have a black line that is coming out of the "T" setting up top, or is that another line that just looks like its there?

[Unchained]

The water dumps straight out of the brass bypass valve next to the hand hole cover just above the steering tube. The black line you are refering to is the reverse bucket cable.

[Q-ball]

Thanks for the info, is anybody getting tired of all my dumb-ass questions yet??

[Q-ball]

Unchained, should I put the valve before or after my first gate valve? It almost sounds like a guy could use one of thse hardware store bypass valves to regulate when the water is injected into his headers more preciecly than the spring loaded t-valve I'm using now.(or am I wrong thinking this??)

[riodog]

Unchained, you have the right idea, BUT, don't be surprised if your bypass valve and brass fittings break off due to vibration.
Q-ball, why two gate valves ? If your bypass valve is set-up properly you don't need any gate valves. As for your headers, run a water supply line from your source up to the drivers seat. Then you use a "water valve"( HI, MED, LOW) FROM Eddie, or Rex Marine, then a line back to the Basset "T" valve (from which you have removed the spring and ball) then to the headers. Water is to be turned on/off at about 1500 rpm.Water Valve-in the Rex catalog on pg 48, $70. Water Pressure regulating Valve-McMaster-Carr, part #9763K49, $27. However, if you do not have a McMaster-Carr close by, you can call Rex, he has some somewhere for about $50.
Leave your gate valve fully open and then set your pressure relief valve for about 12-15 lbs (about the same as a radiater)-the valve will not be screwed down very far.(in-pressure increase/out-pressure decrease.
Actually, a better method of mounting than that in the photo would be to mount the valve on the inside of the transom and then use another dump to the back of the boat. If unchained's valve broke off (it's hanging out there in all of the turbulance plus the vibrations) under a full power run he's got about ten seconds to figure out his motor is NOT getting any water and ooooppp's.
riodog

[Q-ball]

Dog, see this is why I get confused. Who is right, who is wrong? Bassetts web site shows a two gate valve set up for a jet boat, unchained says one thing you say another. I really do appriciate the help from everybody, but are you starting to see why I ask all these annoying, dumb-ass questions? I think I have deciced to run 6 seperate systems, I figure all I need is 11 bypass valves, 14 gate valves, 7 T's, 22 90 degree elbows, 83 feet of 5/8 hose, and 61 feet of 1/2 inch hose. Oh yea, almost forgot the clamps, let's see thats 23+14+33+7+........
Thanks for all the help. When my boat is done (next month I hope) I'll post pictures so you can see where everybodys knowledge and my $1959.23 went!!!

[Unchained]

Riodog, It's such a finely tuned piece of perfomance equipment that there is no vibration.(jk) Good point about the vibration. I have run it for a year that way with no probs so far. I really don't think the turbulance is bad in the area that I have the valve mounted. It's high and dry when you're planed out and mounting outside the hull eliminates extra piping and another hole through the hull. The weak link would be the pipe nipple that screws into the pump. Maybe I'll change that to a stainless one for cheap insurance. As far as the gate valves I think that you do not need one going into the block but will need one exiting the block for the Bassett header valve to work right. Then you can adjust the point that the header water comes in. I am not a fan of the manual header valve. After a couple beers I would forget to turn it on or off. Anyone else driving the boat has no clue what it's for.

[LVjetboy]

Q-ball,
Several different approaches work fine, not necessarily a matter of “right” or “wrong”
Bassett’s web site diagram is pretty weak:
http://users.lvcm.com/lvjetboy/BassettCooling.gif
The inlet gate valve on the left serves triple purpose:
1) Adjust coolant flow at idle to maximum temperature (180-190)
2) Limit block pressure at high rpm and high flow.
3) Serve as a safety cut-off if you blow a line.
Coolant flow temperature can be maintained with a Rex thermostat control or with an inlet valve, and block pressure will be safe if you size your inlet and dump line(s) correctly. I have two dump lines (no dump valves) and even with the inlet valve at full open (5k rpm) I do not overpressure the block. And I normally run with the inlet at about half because no there’s need to bleed excess pressure from the pump...that’s a performance loss. At the half open setting, the maximum block pressure is about 5 psi for my setup...so I could turn a lot higher rpm and still be safe.
You still need some sort of safety shut-off on the high-pressure tap from the pump. Block pressure can be kept safe with a manual or pressure relief valve as Unchained has on his pump. The drawbacks to a pressure relief is the possibility of dirt or sand jamming the relief mechanism causing overpressure, and the extra expense. Jamming may not be common, but it can happen. With correct line sizes, a pressure relief is not needed. But they can work just fine if you want to buy one. If you do go with a pressure relief, setting at 15 psi should be fine. I believe head seals can hold more than this...possibly as much as 30 psi? I think radiator caps (15 psi) are based on car radiator pressure design limits and not necessarily on engine or head gasket pressure limits.
The dump valve on the right in Bassett’s diagram is to restrict and back pressure the engine coolant circuit to open the T-valve at 1500-2000 rpm...supplying coolant to the headers. Even though this is Bassett’s instruction, I would not recommend any restriction or valve on the dump line (unless you use a pressure relief off the pump) because of the risk of blockage or accidentally closing it too much and over-pressuring the engine. For example, if you open the inlet valve more come summer (warm water) and forget to re-adjust the dump valve, you run the risk of over pressuring the block and flowing too much to the headers.
Instead of a dump valve, I would use a valve downstream of the t-off for the headers (on the engine circuit) to backpressure the headers at the proper rpm. The dog’s driver shut-off works too, but like UC mentioned, after a long day of cool ones at the lake I’d likely cook the headers with a manual control. The less to worry about the better come party time. Sh*t, I’m lucky to remember the anchor...
jer

[fat rat]

This has been some very good info for people running O/T headers, but what about some of us running T/T headers. I've heard we should not restrict flow from the pump and I've heard we should, of course depending on who you ask. Right now I have a problem biulding water temp past 140 with 75-85 degree water intake temp (lake temp) and can't biuld water temp over 100 degree with 40-50 degree intake temp. I thought of runnig a gate valve off the pump to front of the boat to control my water temp..........but nobody agrees or disagrees with me.....why? I hope someone can give me a solid answere. Thanx

[jimmmyb]

hey unchained where do you have your boat,
is that snow on lower right corner ?

[Wet Dream]

You let other people drive your boat???

[Q-ball]

Jet boy, Thanks for taking the time to help clear things up for me, I think I have a much better understanding now. Now I wonder if the hardware store will take back the 255 fittings, clamps, and valves I bought.....(jk)!!

[Unchained]

Jimmyb, That's snow coming under the door. I'm in Mi. and took that pic in Dec. after I got the new Digital Camera. It's been warmer here lately, 58 today.
Wet Dream, I have to let friends drive when I water ski. By the way the tunnel is the best boat to ski behind I've owned. There's almost no wake. No place to stow the ski either.
Q-ball, You could use all those fittings to build a unique "Rube Goldberg" system.

[Q-ball]

Unchained, "RUBE GOLDBERG"??? I'm not even going to ask!!

[Unchained]

Qball, Look up "Rube Goldberg" on a computer search engine. He was a famous cartoonist who was known for drawing complicated machines to perform simple tasks. It's some funny stuff.

[SB]

I get confused too. If you're really concerned with water temp., I guess the answer is: use a thermostat instead instead of a restricting valve. Now my question is, on a BBF, if I switch from logs to thru transom headers, what needs to be changed?

[LVjetboy]

Q, one thing I forgot to mention was line sizing. I haven't seen this written anywhere, but I think dump line flow area should be at least twice the size of inlet line flow area for non pressure regulated setups. In other words if you have a #8 into the engine, then have two (unrestricted) #8's out. Here's a picture:
DragnCool (http://www.angelfire.com/extreme2/dragnjet/CoolingDiagram.html)
FatRat, I've only run OT and logs, but I think TT's have many of the same issues (pressure, temp, reversion...etc) I know Lightning headers have different injection options that may affect setup.
Ideal engine coolant temp is an ongoing debate, but 100 sounds a little on the cool side. I think the important thing is oil temp, which tends to run hotter than a car, especially if you do a lot of high speed cruising. So for example, even if your coolant temp is 140-160, your oil temp could be at a toasty 220+ ...plenty to cook off the bad stuff.
Lines to a driver control work fine, but that's a lot of line to run and conceal, and a little extra weight when full of water. Also one more thing for the driver to play with...a thermostat is set and forget.
jer
[This message has been edited by LVjetboy (edited February 25, 2002).]

[Aluminum Squirt]

Bare with me, this is my first post. I've got a white water jet(15', TBI350 with rewarders and a Legend pump; sold by Jetcraft but made by Eagle) and this post is very interresting to me. Currently I run an automotive style water pump. I want to take it off and run my pressure of the drive pump. From all of your posts I'm probably going to run the blow off valve in conjuction with a thrmostat. I do run is some shallow/sandy water on the Feather river. Would it help to run a sea-strainer like the off-shore boys do and then run it through the blow off valve and on to the thermostat? This would keep both my blow off valve and thermostat free of sand/pebbles. Will this present the strainer with too much pressure? Last question and unrelated to the first-Does anybody have experience with Walt's Hot Boat Service in Modesto? I'm not in SoCal and I want my pump flowed and a loader put on. The only shop near me that I've heard of is Walt's Hot Boat Service. I'm in the Sacramento area. Thanx for all of your help and all of the posts I've been reading from the sidelines for so long-Aluminum Squirt

[SoggyJet]

Hey Aluminum Squirt,
I have only heard good stuff about Walt's Hot Boats. He was happy to answer my questions and made lots of helpful suggestions. He should be able to help with your pump and cooling questions.
Doug