Overheating Jetboat

[78bahner]

:confused: I just got this 78 bahner from a buddy of mine and it is the first jetboat i've seen with a heat problem? Its had two motors in it from the time he had it till now (a new 454) and the heat problem has stayed the same. I am runnin a berkeley 12jc and just rebuilt the tired jet thinkin that would solve my problems but they stayed the same. It is runnin a constant 180 and 210 as soon as you idle leading to a higher temp sometimes? I am runnin a intake and exit valve which are both wide open the whole time 1/2 inch line all around except for the headers. I know the jet and intake side are clear and not plugged and the headers are getting plenty of water as well as the water exiting the boat. What could be the cause of these high temps?? Too small of line? plugged hose? The water enters the boat and tee's to the water pump inlets from there it exits the waterneck through the headers in one port and straight out the back from the other port.

[sidewound]

Are You running a thermostat setup? Could be a problem there.
Peace Man!:cool:
CESAR

[78bahner]

Nope, no thermostat...most people that are using them cant get the temps im getting thats what i dont understand why a new pump with cold lake water would get that hot?

[MudPumper]

If you have good water flow coming in and out, maybe check the Temp sending unit and the guage. Might be getting a false reading.

[78bahner]

Yah I thought about the sending unit. The stream leaving the boat is like the same flow as the bilge pump decent i guess but i would think the pressure would be a lot higher coming from the jet pump.

[MudPumper]

If my valves are open, the exit water shoots out way farther than the bilge ever could. You may have a flow problem.

[RiverToysJas]

Isn't 180-210 a good temp range??? Esp for a Chevy. The problem I've seen more is jets running too cold.
RTJas :D

[mavjet]

Try 5/8 or 3/4 hose and see if that brings it down.I agree with Rivertoy,most jets run too cold.Most new autos run at 200 temp,with a 195 thermostat,so really not a problem.Try the 5/8 hose and see if that brings it to 180/190.That would be fine.
What is the highest temp idling for a while?Does it cool down going across the lake?If it does,you have no problem.
My 2 cents......

[Moneypitt]

!st, what size pipe thread comes out of the jet? should be at least 1/2 pipe. You said you have 1/2" hose all the way. That may be where your problem is. Think about it, one 1/2" hose to two 1/2" hoses. You may be loosing pressure right there. Try 3/4 hose off the 1/2 pipe nipple from the jet, into two 5/8" hoses into the front of the motor, and two 1/2" hoses off the water outlet, and out, either through the headers or dumped. This combo will create a little back pressure in the motor, and make the water slow down enough to absorb some heat before it passes through the motor. Another thought, late timing WILL make an engine run hot, is your timing advancing properly.....?? Try that hose set up, its worked cooling my 69 Tahiti for years.........Moneypitt

[78bahner]

Yah i guess the 190-200 range isnt a bad thing, but it doesnt seem normal compared to every boat ive been around unless they are running a thermostat set up? At a idle its 180 after a few good runs it cools to like 170 after I slow down it soars up to 210. I will try the different hose size combo to cool it down I think the intake valve is a 3/8 to 1/2 hose for the rest of the system. Every jet i been in runs betweem 130-150 no matter how hot of a day or how hard your smashing on it thats just what i been using for a "Norm"?

[Foggerjet]

Read Moneypitt's post again, I think he nailed it. I run a 5/8" lake water (in), and a 5/8" water overboard and a -8 AN to the exhaust. The water overboard shoots about 6 feet behind the transom while cruising. If you are just dribbling water like the bilge pump, you've got a restriction. Not debris in the line, just too small of a line.
fog

[Taylorman]

What size is the pipe thread coming off the pump on a JG pump. My E pump is 3/8. You can only flow as much water though the engine as you can put through that 3/8 NPT fitting at the pump. I don't see how going to bigger line than 1/2 fixing your problem.

[Rubths]

Originally posted by RiverToysJas
Isn't 180-210 a good temp range??? Esp for a Chevy. The problem I've seen more is jets running too cold.
RTJas :D
Question Rivertoysjas. Whats wrong with running cold on a chevy motor? I run my valve wide open and my temp guage never moves at all, runs below 120. Is this bad? I can restrict my valve to get a higher temp buts whats a good temp?
Everyone?

[RiverToysJas]

Originally posted by Rubths
Question Rivertoysjas. Whats wrong with running cold on a chevy motor? I run my valve wide open and my temp guage never moves at all, runs below 120. Is this bad? I can restrict my valve to get a higher temp buts whats a good temp?
Everyone?
Nothing is wrong with running cold. You just won't make your full power potential. Used to be said Chevy's don't make power until they are over 160. That's what the old drag racers used to say. Running cold won't hurt anything, though I believe your oil never really thins down.
I ran my value wide open for a while after the engine was rebuilt. Then I start pinching it down until I was pulling around 180 most of the time. If it starts to creap up (towards 210) after a long idle, like through the channel in Havasu, I'd just wrap the gas few times and push some fresh water into the system. I ran a 460 Ford, the priciple is the same.
RTJas :D

[jetboater5]

I think your 1/2 line in is to small creating to much pressure pushing the water through to fast, which is creating air pockets in the system, I run 5/8 hose of the pump then T into 2 5/8 hoses into the headers then from the headers I run 3/4 hose into the front of the block and then run 1 inch hose to the riser which dumps into the exhaust about 22 inches from the center point of the riser. By running the hose like this it pre heats the water going into the block and also allows the water to stay in contact longer so you can keep heat in the engine. I run 140deg all day long,when going in the channel it might reach 160 deg but a quick rpm change will settle it back down

[Cas]

I'm also going with Moneypit on this one but there's one other thing to check. Pull the thermostat housing to see if there's a metal plate with a hole drilled through it. If so, that's restricting the water flow quite a bit.
I had a similar heating situation as you, just not as high. When I took that restrictor out, the temps went down quite a bit.

[kachina_labala]

I had a problem when I switched to lightning headers , the headers did not flow enough through them to keep the bbc cool (no thermostat) how about checking the flow after the motor before the headers? Maybe allow some water to escape there.
Matthew

[kachina_labala]

After re-reading the post I have another query to everyone here. Wouldnt you expect the engine to get "milkshaked" if the pump is allowed to dump unrestricted water pressure into the motor ? I know I had that problem. If its not doing this I would suspect that the restriction is between the jet and the motor.
just thinking out loud
Matthew

[Taylorman]

Im thinking all these are good suggestions but going to 5/8 or 3/4 inch line will not fix his problem. You can only flow as much water as the smallest line in the whole cooling system. That smallest line is where the water comes off the pump, 3/8 NPT. How is it that 3/4 inch hose will help when the inlet water is going through a 3/8 NPT fitting which is much smaller than 3/4 inch hose? I admit, i don't know the answer to his problem but i don't think larger lines is it. The issue about unrestricted water going into the engine should not be a problem. The problem is to much restriction coming out of the engine which causes high block pressure resulting in milkshake. You basically have one line going into the engine and two coming out. I tap into the inlet water to feed my headers and water coming out the engine goes straight overboard. Block pressure stays low and i don't have to restrict water coming in or out of the engine.

[Taylorman]

What kind of headers?

[OMEGA_BUBBLE_JET]

Originally posted by RiverToysJas
Running cold won't hurt anything, though I believe your oil never really thins down.
RTJas :D
Water temp should not be confused with oil temp. I can assure you that an engine turning 3000+ rpm for extended periods of time is heating up the oil. Not flaming just don't want the 2 to be confused and yes oil temp is more important than water temp.
Omega

[78bahner]

Im running Bassett headers without the bassett tee. I put a regular tee in thinking the bassett one was pluggin up and installed a ball valve in the line to control the waterflow to the headers

[78bahner]

I attached a pic kinda hard to see whats going on its not pretty but i'll explain. The 1/2 line from tee's and feeds those 1/2 in lines going to the waterpump holes. The lines off the waterneck are 1/2 in one tee's and feeds the bassett headers and the other line goes straight out the back of the boat

[Foggerjet]

Taylorman has a good question, but there is a big difference between 1/2" NPT and 1/2" hose. Or 3/8" NPT and 3/8" hose, for example: grab a 3/8" pipe nipple and a piece of 3/8" fuel line, there is a huge difference, roughly twice the size. Taylorman, you have a 3/8 NPT pump outlet, are you running 3/8" fuel/water hose for cooling? I'd bet not. I'm not bashing or anything, Taylorman is a stand-up guy for sure. I'm just pointing a few things out.
fog

[78bahner]

Yah your right the valve is 3/8 but the line is 1/2 in hose and its half inch hose through out the boat for the cooling system
_________________________
"Drive it like you stole it"

[Taylorman]

Originally posted by Foggerjet
Taylorman has a good question, but there is a big difference between 1/2" NPT and 1/2" hose. Or 3/8" NPT and 3/8" hose, for example: grab a 3/8" pipe nipple and a piece of 3/8" fuel line, there is a huge difference, roughly twice the size. Taylorman, you have a 3/8 NPT pump outlet, are you running 3/8" fuel/water hose for cooling? I'd bet not. I'm not bashing or anything, Taylorman is a stand-up guy for sure. I'm just pointing a few things out.
fog
True and good point. My point is this though. The hole in a 3/8 NPT fitting is not any larger than the hole in 1/2 hose right? So what good would it do to run hose any larger than the hole in the 3/8 NPT fitting coming off the pump?

[Rubths]

Originally posted by RiverToysJas
Nothing is wrong with running cold. You just won't make your full power potential. Used to be said Chevy's don't make power until they are over 160.
RTJas :D
How much hp do you think im loosing running that cold? motor is a .30 over 454 with big Merlin heads 8 1/2-1 compression.

[Foggerjet]

Dammit Taylorman, Now ya got me thinking :confused: I'm gonna go outside to the shop and rummage through roughly 46 boxes-o-shit and find something to measure. I think (or at least thought) that a 3/8" NPT was about 5/8" actual measurement. But hell I'm not sure now. This is good discussion
fog

[MudPumper]

Originally posted by 78bahner
Im running Bassett headers without the bassett tee. I put a regular tee in thinking the bassett one was pluggin up and installed a ball valve in the line to control the waterflow to the headers
Hey Bahner, I just wanted to inquire if you have water to the pipes at idle or not. You will get water in the motor if you do. The Bassett T is used to cut off water to the headers at idle. It doesn't always work that well but that's what it is supposed to do. Anyway, I just wanted to ask because I learned the hard way when I got my first jet.

[78bahner]

No, I have the valve turned way down it comes out around 2000 or so after enough pressure is built in the system. A little water comes out the weep holes in the bottom or the headers. I wish I had that basset tee back this setup works, but you always have to watch it. Id rather be watchin the bikini's and not the headers.........haha

[MudPumper]

Good deal, just wanted to give you the heads up incase you didn't know. I wish somebody would have told me once. LOL

[78bahner]

Yah I appreciate it, I been in enough friends boats before aquiring this one to see all the nightmares that can and will happen if you just let things go. Its bad enough to babysit 2 or 3 drunk co-pilots and have to babysit the boat too!! I got another problem I got a bad hesitation at 4000rpm? Once it gets there it starts studdering and whont go any higher in rpm? If you let out and hit it and let out and hit the gas again it will jump past it? I just put a 850 holley double pumper on it and the plugs look fine no carbon foul or black smoke coming out the back. It has a hesitation if you just jump on the throttle as well? Could it be a lack of fuel or too much? I was told it might not be gettin enough cause the plugs look fine? Its a .030 bored 454 with a mild rv cam, stock heads and single carb tunnel ram. It has a mallory unilite mechanical advance dist. the timing is set at 10 degrees?

[squirt]

You might also want to inspect your valve thats comming off the pump. It's probably as old as your boat and taking it apart for a little inspection sure wouldn't hurt. If your pump is good & you are running with the valve wide open I would sure be worried about having too much block pressure.
Good luck with it hope you find the gremlin:)

[78bahner]

Yah I checked that and replaced it when I did the pump 2 weeks ago and it was fine. I dunno its a mystery I thought i might have been on to something with the hose sizes but looks like everyone ruled that out? I just dont get it new pump, new motor, valves are clear, must be a line....but i checked those and they looked ok? Not even that much pressure coming out of the dump in the back? what is a high or low block pressure, maybe I should put a gauge on the motor and see what pressures im getting?

[squirt]

That what I did, I run around 160-180 idle and around 130 running at 15 PSI water pressure. This is a SST oil filed gauge that I got from Graingers for under 10 bucks:D
http://www.hotboatpics.com/pics/data/500/3664gauge2-med.JPG
Have fun....Don

[NAMarine]

The valve you show in your pic looks to be a normal valve for 1/2 npt which when you measure ID you will find to be about 3/8" they do make a full flow valve that is 1/2" and you want to change out to it. A full flow valve is very bulky for it's size and will not ristrict water flow.

[Hemicbx]

OK, here's a technical response to Taylorman and Foggerjet regarding the use of larger ID hose.
Pipe is sized by nominal ID. OD does not correspond to the pipe size until you get to 14" pipe, then pipe size & OD are the same. Pipe always stays the same on the OD not matter what pipe schedule (strength, wall thickness) you're using. The ID shrinks.
The OD of 3/8 pipe is .675". Nominal ID is just about 3/8", but that varies depending on pipe schedule (weight). Notice that 5/8" heater hose will fit neatly over the 3/8" pipe nipple.
The reason that a larger hose will help, even with a 3/8" pipe nipple off the pump, is due a thing called fluid friction. This is especially true with a centrifugal pump. Centrifugal pumps can pump a given amount of flow against a given amount of restriction. If you increase the restriction, they will flow less; likewise if you reduce the restriction, they'll flow more.
Fluid friction is related to the fluid velocity in the hose, the hose ID, and the fluid itself. Fluid friction is the friction caused by the fluid flowing through the hose. Fluid friction causes resistance against our pumps. We're not changing fluid, it will always be water. If you can increase the size of the hose, your velocity in the hose will go down for the same flow or you will be able to flow more water from the pump to the engine because it will take a larger flow rate to build up that much friction in the larger hose.
However, a point does come when Taylorman is exactly right. Eventually, the restriction to flow through the 3/8 fitting will become the "controlling resistance" and it won't matter what you do downstream.
We can go into a bunch of fabulous things like Moody Diagrams, Reynolds numbers, and Bernoulli's equation, but I really don't want to do that right now.
Hemicbx

[78bahner]

The valve in my pic just feeds the headers, but i unserstand what your saying about the sizes maybe i'll change those. I think im just gonna eliminate the exit valve I never use the dam thing

[78bahner]

So should I run a 5/8 hose off the pump and tee that into the two 1/2 hose lines feeding the engine? What should I use for my dump line 5/8?

[Taylorman]

I think 1/2 hose is 1/2OD not ID. I use stainless hard stainless tubing which is 1/2 od but the id is larger than the 1/2 hose. I'll do some measuring tonight.

[Crazy Squeeek]

Does anybody have a diagram showing how to plumb the cooling system with a Hi Tech pressure valve and a Banderlog header water control system? There's to many valves involved for my lil P brain to understand :confused:

[78Eliminator]

I would pull off every connection and check to see if there are calcium deposits which are clogging the water flow. I have seen hoses that attach to the block, where when I unscrewed the AN fitting, the passage was 100% filled with calcuim.
The problem with running pure water as opposed to radiator fluid, is that mineral deposits accumulate in your heads, block and intake manifold. Double check all inlets and outlets first. Easiest to fix, just hollow it back out with a screwdriver.....
Justin

[Taylorman]

Originally posted by squirt
That what I did, I run around 160-180 idle and around 130 running at 15 PSI water pressure. This is a SST oil filed gauge that I got from Graingers for under 10 bucks:D
http://www.hotboatpics.com/pics/data/500/3664gauge2-med.JPG
Have fun....Don
Hey squirt, whats the spark plug wire connected to your intake do?

[kachina_labala]

what about hooking a garden hose to the hose where it would connect to the pump. Its a known fixed flow (no im not saying run it on the trailer) . Then you can disconect hoses in various areas and see if you are still getting full flow at those points such as before and after the engine.
By the way there is a header t valve on e-bay
ebay Basset t (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2475345014&category=31285&sspagename=WDVW)

[Foggerjet]

Hemicbx, thanks for the info. Taylorman, where is your "home" lake? I had a buddy in the army who was from around your way, I went on leave with him once, and his dad took us skiing on a lake but I can't remember what the hell it was called. It had a bunch of REALLY nice houses on it. Anyway, real nice country, good food too.
fog

[Taylorman]

Originally posted by Foggerjet
Hemicbx, thanks for the info. Taylorman, where is your "home" lake? I had a buddy in the army who was from around your way, I went on leave with him once, and his dad took us skiing on a lake but I can't remember what the hell it was called. It had a bunch of REALLY nice houses on it. Anyway, real nice country, good food too.
fog
I boat mostly in Henderson. Would that lake be called False River or Toledo Bend?

[Taylorman]

Originally posted by Hemicbx
OK, here's a technical response to Taylorman and Foggerjet regarding the use of larger ID hose.
Pipe is sized by nominal ID. OD does not correspond to the pipe size until you get to 14" pipe, then pipe size & OD are the same. Pipe always stays the same on the OD not matter what pipe schedule (strength, wall thickness) you're using. The ID shrinks.
The OD of 3/8 pipe is .675". Nominal ID is just about 3/8", but that varies depending on pipe schedule (weight). Notice that 5/8" heater hose will fit neatly over the 3/8" pipe nipple.
The reason that a larger hose will help, even with a 3/8" pipe nipple off the pump, is due a thing called fluid friction. This is especially true with a centrifugal pump. Centrifugal pumps can pump a given amount of flow against a given amount of restriction. If you increase the restriction, they will flow less; likewise if you reduce the restriction, they'll flow more.
Fluid friction is related to the fluid velocity in the hose, the hose ID, and the fluid itself. Fluid friction is the friction caused by the fluid flowing through the hose. Fluid friction causes resistance against our pumps. We're not changing fluid, it will always be water. If you can increase the size of the hose, your velocity in the hose will go down for the same flow or you will be able to flow more water from the pump to the engine because it will take a larger flow rate to build up that much friction in the larger hose.
However, a point does come when Taylorman is exactly right. Eventually, the restriction to flow through the 3/8 fitting will become the "controlling resistance" and it won't matter what you do downstream.
We can go into a bunch of fabulous things like Moody Diagrams, Reynolds numbers, and Bernoulli's equation, but I really don't want to do that right now.
Hemicbx
Ok, you sound like you know more about fluid flow than i do. I can appreciate that. Maybe a 5/8 hose can flow more water faster than 1/2 even with 3/8 NPT fittings. My point is this though. No matter what you tell me, i don't believe that going to larger line will help his problem with high temp. Like you said a 3/8 NPT fitting measures 3/8 ID and 1/2 hose meausures slightly less than 1/2". My boat is plumbed with 3/8 NPT fittings with -8 AN flares and 1/2" stainless tubing throughout. If i leave my ball valve open it will run about 120-130 degrees. Im running an olds 455. I can't imagine a chevy making that much more heat so that he has to use larger than 1/2 line. Just my .02.
Kevin

[Duane HTP]

If all else fails, Chevrolet made three different configurations of head gaskets for the 454. The marine and truck blocks had water cooling holes between the lower row of head bolts on the heads. The earlier ones and some car ones did not. If you have the wrong head gaskets on or a set of heads with the cooling holes on a block with out them, that could be your problem. It's easy to solve. You just drill four 3/16" holes in the deck of the block to match the ones in the head gaskets. If you buy Felpro head gaskets, they usually have the instructions in the package.

[squirt]

Originally posted by Taylorman
Hey squirt, whats the spark plug wire connected to your intake do?
Why it lights off the exit water of course:D
It's just that blue wire covering stuff......thats the h2o temp sending wire:p Always wondered about the color code for the jets...Blue is oil, brown is water.....I'm not getting it:confused:

[78bahner]

Yah that is a good question< I just had the heads off because of a faulty gasket from sitting so long. I never paid attention to the holes or anything just went and bought a set of felpro gaskets and away I went. I dunno the boat had a 396 in it and had the same problem..I since yanked that and put in the 454......with 427 heads?? I wonder if that match is causing some problems?

[396_WAYS_TO_SPIT]

Originally posted by squirt
That what I did, I run around 160-180 idle and around 130 running at 15 PSI water pressure. This is a SST oil filed gauge that I got from Graingers for under 10 bucks:D
http://www.hotboatpics.com/pics/data/500/3664gauge2-med.JPG
Have fun....Don
Whats the part number for that guage? I need 4 of them
396

[jim lee]

Does anybody have a diagram showing how to plumb the cooling system with a Hi Tech pressure valve and a Banderlog header water control system?
Just make sure that the Banderlog valve is first in line from the pump. (highest pressure) Then do what you have to do to make the motor happy.
-jim lee

[78bahner]

I bought the Bassett tee off of e-bay, thanks for the heads up! I put 5/8 from the pump teeing into 1/2 in. lines feeding the engine. I am then gonne exit the water through the headers and out the back with 1/2 lines. We'll see how that goes?

[jim lee]

I am then gonne exit the water through the headers and out the back with 1/2 lines.
Wait a sec. Are you saying that your going to pump -all- the cooling water through your headers? If they are injected headers this won't work. Most of your water is just dumped overboard, just a little of it goes through the headers.
Misprint, misunderstanding right?
-jim lee

[MudPumper]

He means two lines, one to the headers, one overboard.

[78bahner]

Yah thats what I meant one to the headers and the other out the back of the boat........

[Hemicbx]

...Maybe a 5/8 hose can flow more water faster than 1/2 even with 3/8 NPT fittings. My point is this though. No matter what you tell me, i don't believe that going to larger line will help his problem with high temp.
Taylorman,
Your most likely right. In terms of pressure drop in a jet boat cooling system, the friction loss in the hose is probably negligible. Someday I'd like to see a good flow/pressure-drop curve for a V8. Would help answer a lot of questions.
I was just giving my post in response to your question about the fitting restriction and how that can relate to hose size.
Later,
Hemicbx

[Taylorman]

If you ever find out, share it with us.
Kevin

[78bahner]

Well Im gonna test the boat out this weekend, I changed the lines to 5/8 main line that tee's into dual 1/2in. lines feeding the motor then 1/2 in lines one teeing into the headers and the other dumping out the back. I bought a bassett tee valve for the headers but i dunno if it will make it here in time I might just run the valve setup i have just to try it.

[kachina_labala]

This is my attempt on water pressure regulation this year.
http://www.hotboatpics.com/pics/data/500/4896DSC00400-med.JPG
its bigger than it looks in the picture! Those are 5/8 hose fittings.
After this reg/filter setup im going to have 3 lines. 1 line to each header ( lightning headers) and one line to feed the motor. the motor will have a 140 thermostat. the outlet from the motor will dump directly overboard. Im hoping the thermostat will act as a temperature controlled flow control and the pressure reducing valve will pass only the flow that is required to keep 25 psi.
Matthew

[78bahner]

Ok heres the results. I changed the primary line from 1/2 to 5/8 and tee'd into 1/2 in. lines to feed the motor. I have half inch line feeding the headers and the other dumps overboard. I didnt really notice a change in temp...a little cooler? I installed a pressure gauge in the intake and got these results 0-pressure at idle, 10lbs at 1500rpm, 25lbs at 2500rpm and 40-45lbs at 4500rpm. I dont know if these pressures are normal or not, I know both my valves are wide open and the one i use for the headers I had to open up more this time to feed the headers cause it wasnt getting the water like it used to? I just had to crack that valve before I changed all my lines. I am coming to the conclusion that the sending unit is faulty or not the right one (just like everything else i had to replace) because a motor running 210 like the gauge says you wouldnt be able to put your hand on the block and hold it there without getting burned.

[MudPumper]

Hey bahner you should look into installing a pressure regulator just after the pump, before the motor. You don't want more than about 25psi going into the motor. Do a search for pressure regulator here in the Jets section there are some threads discussing it with some pics also. Actually there is a pic right above from Kachina. But check into it. Insurance for your motor!!;)

[kachina_labala]

The regulator is a Watts, p/n N35BU that is a Grainger p/n 6LM11.
And a link to the filter is.
strainer (http://www.boatersworld.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&catalogId=10051&langId=-1&productId=708715#description)

[Taylorman]

Two dump lines instead of one will get your block pressure down to where it need to be. Instead of supplying your headers with water from the intake t stat housing, tap into the line between the pump and engine. This will reduce the amount of water going to the engine which will reduce pressure and it will give you two dump lines which will also reduce block pressure.
This is the SEA STRAINER (http://www.groco.net/images/strainers/WSB1250-1250-P-500.gif) i used in my boat. Cost like $30 and it works fine. Got it from West Marine.

[Punisher]

That what I did, I run around 160-180 idle and around 130 running at 15 PSI water pressure. This is a SST oil filed gauge that I got from Graingers for under 10 bucks:D
http://www.hotboatpics.com/pics/data/500/3664gauge2-med.JPG
Have fun....Don
Squirt, where didja get your intake manifold hose fittings from? Those look suh-weet!

[Punisher]

This is probably overkill, but could you use this on the line from the pump? Regulating Electric Manifold (http://www.accuspray.com/productpages/Banjo_RegManiValves.php)