Pressure Sensor

[HOSS]

Jet pressure topic got me thinking. I would like to install a pump pressure sensor in my pump. Anyone done this and where should it be located. Would like to see "first hand " what my improvements actually do. Should there be 2 sensors. One at intake and one before steering knucle. Where can I drill and tap safely? What sensor and gauge. I really see this being beneficial for signs of pump wear and impeller fatigue/failures.
I would think a sensor could not be placed at the top of intake because of many variances like air (main one)but can see one on the bowl. Would you recommend having a JG so as to place it in the snoot?

[Hotcrusader76]

HOSS,
I am working on a "Patented" Emergency water-cutoff system for Jetboaters, which also serves the purpose of regulating the water pressure coming off the jet automatically with a 12VDC power source (your battery) and regulating proper system pressures. These pressures often depend on engine RPM and pump type/work performed.
There are many manufactures out there that sell gauges and or sensors with many types of signal returns; 1-5VDC, 2-20ohms, 5-40mA, etc.
Check the Grainger catalog for such a device. They have been an awesome source for components of that nature and offer a great deal of help on proper selection of parts.
As far as your other question with regards to location, you might want to contact Froggy and or Greg @ G&S Marine. They have always offered a wealth of reliable information on these types of questions.
~Ty

[Blown 472]

How would your system work?? are you talking about shuting off the inlet water??

[Hotcrusader76]

Without getting into too much detail.
If your boat suffered a water line rupture anywhere within your raw water system my system will activate an electrically operated valve that will be signaled to close off the Jet's water outlet from a strategically mounted sensor(s) and in-turn signal the helm with a visual and audible alarm that your system has been triggered.
You then have 8-10 seconds to safely navigate your craft to safety (away from a jetty or levee at 70mph) before the E-Valve system shuts down the engine, which will prevent your motor from overheating and burning your Chrome off the headers.(due to the fact your water system has been shut-off).
It will be offered in stainless steel and powdercoat finishes of choice and utilizes a small electronic box (The black box), which contains all the necessary circuits to arm and disarm the system.
Along with this “E-Valve system” as I call it, there will be a regulator mounted inline to manually regulate the amount of water your motor will see to prevent head gasket bursting or exhaust valve water reversion. It too will have a gauge and sensor mounted so that adjustments can be accurately made.
It will be prototyped this season on three different boats all utilizing different pump types; Berkley, Dominator (sort of different), and Panther. Be on the lookout! wink
[ February 05, 2003, 01:14 PM: Message edited by: Hotcrusader76 ]

[Blown 472]

Interesting, what about the motor, any way to back the rpm down?

[Hotcrusader76]

My design had to be capable of supporting all ignition types and by getting into RPM limiting with RC Circuits and where to get the signal, it's easier to attack one area of the motor to shut her off.
Otherwise Yes! An easier design would be to limit the amount of spark and bring the RPM down gradually. But not everyone uses high end electronic ignitions which would help in the design.
All in all my system will weigh less than 7-8lbs and will be very competitive in price.
[ February 05, 2003, 01:19 PM: Message edited by: Hotcrusader76 ]

[Blown 472]

Sounds cool, good luck to you. wink

[Froggystyle]

I have my intake pressure gauge port at the second "E" in Berkeley. Drill right through the center of it, and tap it with a 1/4" pipe tap.
I then run a pressure gauge with a 10' hose into the passenger compartment. This is used to diagnose intake loading issues. I don't know where to tap for the pressure side. That part was not a concern to me.
Squirts up!

[HOSS]

Anyone got pics? Froggy, just curious, why only on intake? Was this done to see if you are properly loading? What impeller and what psi at what rpm? Also, did you notice changes with loaders or impellers. What about diverters, droops, nozzle sizes?
[ February 05, 2003, 07:01 PM: Message edited by: HOSS ]

[flat broke]

Hoss,
The main reason most folks only measure the intake side is because they are looking to see the effects of their running gear setup on the amount of water being fed to the impeller. To measure your increase in thrust, all you need is a tach, GPS, and known baselines. If you increase your thrust (pressure side) you will see icreased performance at a given RPM.
Chris