Water Pressure relief Valve
 

Where can you buy a water pressure relief valve?
And what is the max water pressure you should have?

Contact Gary @ Grimes Auto Marine in GA. He's got a deal they make that is adjustable, and will flow all of your excess so you don't have any problems. (770) 475-5272

This is the water pressure valve I use. I put a tee after my oil cooler and before the cross over. I ran the tee run to the flow control shown. It is kinda hard to see against the black background. It is adjustable and dumps overboard. It is a Deltrol part number EF30B. It is made out of brass and has 1/2" NPT ports. I use 3/4" heater hose and crome plated brass fittings from CP perf. I made the tee out of aluminum on a lathe. It works great. I have it set at 23 psi at WOT. If I shut it off it runs at 32 psi. The valve can be purchased from a McMaster Carr catalog, or I could get one for you. Let me know if you are interested.

I have a Gary Grimes set up...
 

Mike,
That is a sweet looking motor. Out of curiosity, where does Gary tap into the system to dump the water? To control pressure spikes on my motor I teed a 10 psi 3/4" check valve before my sea strainer. This will open and dump excess water at inlet pressures over 10 psi. I didn't mention this earlier because it really doesn't control the pressure, just gets rid of spikes. In my opinion the inlet side of the system is where spikes have to be relieved. If the spike makes it past the pump, the motor is going to see that spike. It may not even show up on the gauge. I have had great success on my motor which makes 700 Plus HP with 13:1 compression. It turns 6200 RPM at WOT, uses a stainless crossover with a 142 degree thermostat which maintains 150 degrees in all conditions. If it weren't right I would be into detonation in a hurry. I don't think it is real innovative, but as a hydraulics engineer it just makes sense. I am curious how his compares to mine. Here is a picture of the check relief on the inlet side of my strainer. If I knew someone had something like this available I would probably have bought it, but it wouldn't have been nearly as much fun as doing it myself.:rolleyes: Nice picture in Hot Boat.

Here we go..........
 

That sounds like a really cool system. You have mentioned it is kinda salty. How much we talkin? This is what I love about HP motor sports. It gives the average joe a chance to tinker and hopefully come up with some cool things. I personally spend more time tinkering on the boat and the corvette than I do driving them. Hopefully Mr. Cig has the answer he was looking for.

Thanks so much for the responses. I see that it is more involved then what I thought.
I will have to look at my setup and see how i can incorporate these ideas on my motors. I have transmissions and coolers that are mounted on the trans housings.
I was thinking of just comming out of the intake manifold.
Do you think that would work or not.

Thanks
Mark

I use the same system Wette Vette has described on my 26 Carrea cat with a 900hp Naturally aspirated 632 Merlin. I had very high pressures and was getting leaks through the intake because of the excessive pressures. Went the no thermostat route which helped, but couldn't get any heat in the motor. Also tried coming out the intake manifold which worked, but sevelrly starved the CMI's. After Wette Vette and I installed this system on my boat, I was able to put my thermostat back in and simply adjust the Deltrol valve until max pressure came down to my target of 20 psi @100+ mph. No spike problems, no leaks through the intake, and no starvation to the CMI's. The best thing is its a fairly cheap set-up to copy. As a side note, based on my observations water pressure really begins to build as you cross 80 mph. As in 40% increases the next 25 mph. :) :cool: MikeHTM, that is a good looking motor, same colors as mine. Did you paint your intake or powder coat it?

He likes em
 

To the tune of 600 bucks. I spent about $140 on the pressure relief valve from McMaster-Carr. Transom dump and fittings went well over $200. I did end up selling it to someone who wasn't running a stat. My problem with my set up was the temp kept fluxuating. I drilled the holes and several different sizes on several stats. No luck. Gary has got a certain stat that he uses to keep temps level. Mine will start out warming up and stop at 180* then it will run about 140 to 150 all the time no matter what rpm. With my ID's being so large I have a lot of room to adjust my pressure. We started out at 14 psi and water tested it. Gary then took the valve apart (5 minutes) and bumped it up to about 18. You should see the water dumping on my outdrive. Megatons of water.
jdnca1, I have a large liquid filled water pressure gauge on the intake. I also have an electric water pressure gauge on the dash. It is not accurate but linier. Do you have a good gauge that you can see if yours does spike?
Will you be at Cumberland on 7/4? I will be up the whole week. Maybe if you are there we can hook up.
Base coat clear coat entire engine. 200 hours no problems.
Wette Vette you housier boy. I was borned in Corydon, IN.

Scotty Cannon's engine in his 25 talon (just like the red, white, and black one on Cumberland). #6 drive 135+ GPS. Scotty is the NHRA Oakley funny car driver. He boats on our lake. The Talon on Cumberland started out in northern IN and my buddy in SC bought it and took out the stock carbed 502 and had John Triplett (Louisville, KY) build a 510, 871 that ran it about 118 on Gaf. speedo.

Yea, JDNCA1 and myself are both hoosier boys. I see that nitrous bottle in the background on Cannons boat. What a wild looking motor. It looks like it could be a tuners deilght with all of those regulators. Corydon Indiana is way down there in good old boy land. Of course anything south of hwy 30 is good old boy land. Post a picture sometime of Gary's pressure control valve set up. I like to see other ways of skining the cat. What do you think JDNCA, that nitrous bottle is getting me thinking. 150 HP at the push of a button for triple digit radar runs! It may be in the Wette Vette's future.:D I will only tell after we go side by side from about 45 MPH. :eek:

Cannon's motor............
 

MikeHTM;

I run a mechanical gaffrig water pressure guage plumbed directly into the block. I just dont trust electrical units anymore..Unfortunately I won't be at cumberland (or anywhere) over the fourth...WEDDINGS, the better half would kick my ass if I missed her sisters so......I'll be at the lake!!! Just kidding. I will be @ cumberland over Memorial day, none-the-less I'd like to meet you sometime..never been around any HTM's. :cool:

I agree on the electrical gauges...
 

but the gauges on my boat have the HTM logo and the only water pressure gauge Steve had was an electric one. Looks pretty. I just couldn't find a sending unit to match the gauge. Got one close though. Whatever it reads I just double it. I really just use it to make sure I do have pressure. Bummer about the 4th. If you get any vacation come down to our lake. It's about 435 miles from Louisville to where I live. By car it takes about 6.5 hours.

WETTE VETTE or MIKEHTMSR24,
Do you think that WETTE VETTE's system would work with a stock 454 with a recirculating pump and a thermostat? It's a '97 carbed 454 with way to much water pressure, 35+. The pressure is taken off the side of the block with a mechanical gauge.

Thanks,
Dan

something ain't right
 

A stock motor w/ rec. pump with water pressure problems. What exhaust does he have. Maybe the the exhaust is the hold up.

Mike,
I'm running Merc/Gill exhaust. The pressure was the same with the stock exhaust manifolds.
Dan

It should work, but with the stock set up there shouldn't be pressure problems unless there is something obstructing water flow out of the motor. How are your temperatures? Do the exhaust have one or two water lines running to them? I have seen guys run both outlets on from the motor to only the bottom line on the manifold and this could cause high pressure. On merc set-ups they run the bypass to the bottom, and the thermostat to the elbow of the exhaust. The bypass keeps the exhaust cool when the motor is cold, and when the thermostat opens that water dumps into the elbow and all of the water exits through the exhaust. It is unusual, but the holes in your collector where the water mixes with the exhaust could be to small or plugged with contamination. I would verify some of these things before dumping water like a lot of guys are doing that are running crossovers. I would hate to see you not put enough water into your exhaust for cooling and burn the rubber where your exhaust tip and collector come together. And remember less pressure will force less water into your exhaust. If the point where the exhaust / water mixes is the restriction, it should be resolved there. Drill a couple more holes and test it out. On my boat my exhaust exits under water when the boat isn't on plane. I was testing different methods and starved my exhaust and burned a hole in the rubber. Basically the boat was taking on water whenever I came off of plane. Luckily I was on a small lake and the ramp was nearby. No prob, just a little scary.

Thanks for the ideas. I only have one hose going from the thermostat housing to the manifold and then the bypass hose from the manifold to the tailpipe. I am going to give Gill a call and see if I should run to lines to the exhaust.

Thanks,
Dan

Can you post a picture? Are there two lines teed together from the motor to one and then one line going to the bottom of the exhaust? Then on your exhaust there is a line that connects the tailpipe to the manifold?

Nevermind the picture, I just looked at a setup like yours in a hotboat magazine. The restriction is more than likely the plumbing that connects your manifolds and your tailpipe. The type of dump valve HTM Mike or that I am using should work just fine. Tee it in after your oil cooler in your main feed line.

WETTE VETTE,
Thanks for the help. I am going to run the boat with one of the thermostats pulled to see the pressure readings. My "Band-Aid" fix will be the McMaster-Carr valve. I was planning on tapping the thermostat housing and running a line to the transom. Do you see any problems with that? The water line on my boat comes right out of the cooler and makes a hard bend right into the T-housing. Thanks again for the help. This is driving me crazy!

Dan

I don't see any problems with tapping the thermostat housing. Just tap it 3/8 or 1/2 NPT and if it doesn't work put a plug in the hole. I know it will work if you tee in right after your oil cooler, but it takes a custom made tee. I know the feeling of being frustrated, but it will be worth it when you get it straightened out.
Good luck.

I just got of the phone with Gary. What a great individual. His first guess is that my problem is in the tailpipes. He gave me some good ideas on how to diagnose the problem. He wasn't interested in selling me stuff. He just wanted to help. Thanks Gary and the guys that are so happy with his products.
Dan

I spoke with Gary @ Grimes Auto Marine in GA who makes the water pressure relief system that MIKEHTMSR24 and RumRunner were speaking of. A very knowledgeable person with race boats. He was evolved with Don Johnson's race boat. That boat had a dump system because of high pressure.

He believes my restriction might be in my tail pipes, not the number of holes in them but the amount of room between the two-jacketed tubes. To confirm this he wants me to tee off the thermostat the hoses that run to the manifolds. I am supposed to put a gate valve in line and have the end of the hoses run over the side. He wants me to run the boat up to 3500 and check the water pressure. Then both valves are to be opened evenly till my pressure drops to 20 lbs. then I am supposed to take it to WOT and repeat to get the pressure to 20lbs. During this time I need to monitor the engine temperature to make sure there is no fluctuation.

The next step is to leave the valves open and bring the boat back to idle. I need to keep an eye on the engine temperature, pressure and riser temperature. If every thing stays the same I can run a dump system without a pressure valve otherwise I need some sort of valve to keep the system with some pressure. The numbers we want for optimal performance is 18- 24. Anything under 16 lbs. at WOT can cause hot spots in the heads. Anything over 24 can cause gasket failure.

I plan to try this set up next week and will make a decision on what to do. The other option would be new exhaust. :( My current exhaust is mercury/Gill manifolds with Rex Marine power flow tail pipes.

Dan

gary grimes
 

nothing but good. through and through.
That's why he has got my business.
A real good person man.;)

are the pressure spikes caused by the pump losing head pressure as the boat is coming out of the water, then suddenly getting the pressure back and then water hammer effect as the pump gets more pressure as it fills the suction hose as it re-enters the water? if so, wouldn't it be easier to fix the suction side for the spikes?
here is what i was thinking, a small tank, filling from the top from your water pickup. the outlet, off the bottom of your new tank, going to the suction of your raw water pump. possibly, a small vent tube overboard off the top of the tank to vent air. as you have a couple spare gallons of water on the suction if you come out of the water, your raw water pump is still spinning, sucks the level down in the tank a little, and it makes some room for the surge of water that will take place as you re-enter the water and keeps a more constant head pressure on your pump reducing or eliminating the spikes in pressure.
you would need to calculate the gpm of water flow when airborne , the time your out of the water , and make the tank roughly twice the capacity of the that the pump will use when out of the water. i'm just thinking out loud. any thoughts on this idea? Fran

i forgot to mention that the water pressure too high problem could be helped by reducing the head pressure to the pump by increasing the vent size off the top of the tank if necessary.

Excaleagle42,

I wish that were the problem. I know the race boats will use a large sea strainer to prevent running out of water. Now I have found they also have a pressure relief to handle the spikes. My pressure is constant on calm water. It is rpm oriented and not speed. Thanks for the input. I should have things worked out by next week.

Dan

Water pressure update! I put a tee off of my exhaust manifolds hooked to a gate valve. With this valve fully open I could only eliminate about 10 lbs. of pressure. Pressure dropped from 45lbs:o to 35lbs. :( I went home and re-rigged the system with a tee just after the coolers before the bend into the thermostat housing. I ran a 1" line through a ball valve and then out of the boat. With the valve a little more than half open my pressure dropped to 20 lbs. :D :D :D I am going to order some pressure valves in the morning.

This is a Band-Aid fix. I believe the problem is the plumbing of the thermostat housing and not the exhaust. The motors are stock 97 Mercury 454 Mags with only one line running to each side of the exhaust. I plan to test this theory over the summer by installing an older style T-housing. I'll keep you posted on the progress.

Dan

Dino at Teague Marine told me today that if I wanted to address excessive water pressure I should not plumb into the intake manifold. At this point the entire engine is pressurized and it is much better to relieve the pressure before it enters the engine. Teague sells a tee fitting for the 1 1/2" raw water line with a 1/2" bung fitting and a variety of spring tensions for the relief valve. He stated the same target pressures as have already been cited by Grimes. The reason I didn't pursue this further is because he told me typically water pressure doesn't become a problem until the boat is traveling above 95 mph. I don't go nearly that fast! I'll measure my water pressure this summer before I know if I've got anything to worry about. I didn't ask the price of the Teague unit. Their number is 661-295-7000.

Where are you guys checking the water pressure? I checked mine in the cross over tube, before it goes into the engine, and I am seeing 29 lbs at Wot. I would think if I checked it in the heads or before the thermostat, it would be a little lower. I have the mercruiser "T" on the cross over tube feeding my Gil manifolds. I am running the "T" without the plastic balls, And seeing 28-29 lbs at the cross over. I was thinking the pressure is high there because of the water trying to fit into the 2 water hole's in the block. but after entering there, wouldn't the pressure drop a few pounds because of all the area it has to fill, or keep full?. Should I be checking the pressure somewhere else? I'm hearing that 22 -25 lbs is perfect, but is 29 lbs to much? I usually wouldn't worry to much, but I am running 5-6 lbs of boost.

Kanookstr,
I check the pressure off of the side of the block with a mechanical gauge. 18-24 is the target pressure at wot. The block pressure is what we need to worry about. The coolers and exhaust can take the extra pressure.
Dan

Thanks Dan, I kinda had a feeling I should check it in the block. I will try and relocate the fitting somewhere in the block. I would like to check it in the head. But the Gil manifolds seem to be in the way if the plug that's in the head.

Rex marine sells a nice setup, they recomend putting it on the water line from your outdrive to the pump

Well I moved the gauge into the block, and I see the same 29 lbs of pressure. I'm going to feed my intercooler from the cross over tube like it was. That should drop it down 3-5 lbs, and put me in the low to mid 20's. We'll see this weekend;)

Ok I finally got the boat in the water. I have over 35 lbs with the stainless marine cross overs with the thermostats in and by-passes. Could only get 130deg.
Took out the thermostats and the pressure drops to 20lbs max. but obviously only about 100deg temp.
I guess i need to reduce the water flow which will reduce the pressure because it cat get out of the the motor because the thermostat never opens.

Mark

Help guys!? I have brand-new rebuild with 30 min of hose time with zero issues and when tested on trailer on ramp pulling its own water up I have llwater in oil alot. Brand-new seaward series manifolds and tails. All new rebuild .Was suspected intake manifold leak and indeed it is I believe I have high water pressure and wasn't seeing it while running on water hose but now on its own it blew intake gaskets. Stock magmpi 502 help me plumb up a relief for pressure ?? ?