Cooling Issues / Steam out of Thru Hull!

[gqchris]

Hey Guys,
Is it normal for your water coming out the dump valve to be HOT and lots of steam? I have had an issue with my boat since I have owned it and just reared its head again since I put my headers back on after ceramic coating. Plumbed it back the way it was, and today fired her up on trailer. Here is the rundown of my plumbing: (Oh, Panther jet also): 454 Mild Build
From Jet straight to -8 line to a tee, then -8 lines to each side of block inlets.
-8 line from top of thermostat to Basset T Valve, the to headers.
Bottom of Intake Manifold another outlet -8 to inline gate valve to overboard dump. I do have some 90 degrees in here, any flow isues with them?
At idle in the river, my temp will climb to 200 or so, but once on the gas, quickly drops, in 5 seconds or so to 120-30. I figured it was because of the Panther pumps setup, and they just dont flow good at idle. Water is always hot coming out the back also.
Today, lit her up on trailer, and temp climbed for a while up to 200. Water was flowing good out of thru hull, but HOT!! Shut off engine, and steam continued to shoot out of the overboard dump for a good 15 seconds or so.:eek: Am i missing something here? Is that normal?
Just for notes: No water in Oil. Clean as whistle. I will take some pics tommorow AM for reference! Thanks for the insight guys.
Chris

[firstjetinMN]

Not sure what is causing your issue, but I do know one thing...You don't want your engine going from 200 to 120 -130 within 5 seconds......
Your going to warp something.... Whatever you do get that temp to stay stable somewhat

[gqchris]

Not sure what is causing your issue, but I do know one thing...You don't want your engine going from 200 to 120 -130 within 5 seconds......
Your going to warp something.... Whatever you do get that temp to stay stable somewhat
Yea, thats what i was thinking. 5 seconds may be stretching it a little, more like you can see it fall over a 20 second time frame.
I wonder if my my main issue is just low water pressure at idle. I think today also my hose had low pressure where i was running it. :idea: Cruising, im fine. Could sand in block do this? Maybe I just had steam pockets from everything getting put back together dry?

[firstjetinMN]

Yea, thats what i was thinking. 5 seconds may be stretching it a little, more like you can see it fall over a 20 second time frame.
I wonder if my my main issue is just low water pressure at idle. I think today also my hose had low pressure where i was running it. :idea: Cruising, im fine. Could sand in block do this? Maybe I just had steam pockets from everything getting put back together dry?
Steam pockets would have worked themselves out right away....Sounds like maybe some sand in the lines, motor or an obstruction in one of the elbows....
Not sure what others run for water lines but I run a 3/4 ID marine grade hose....maybe those -8 AN are too small if your pump has poor pressure output ?

[Squirtin Thunder]

From Jet str8 to -8 line to a tee, then -8 lines to each side of block inlets.
I have a dump right after the inlet of the pump to cut presure down with a gate valve. Coming out of the T are the lines the exact same length ?
-8 line from top of thermostat to Basset T Valve, the to headers.
You need to have a way to shut the water down to the headers.
Bottom of Intake Manifold another outlet -8 to gate vale to overboard dump. I do have some 90 degrees in here, any flow isues with them?
That is fine.

[BrendellaJet]

Steam pockets would have worked themselves out right away....Sounds like maybe some sand in the lines, motor or an obstruction in one of the elbows....
Not sure what others run for water lines but I run a 3/4 ID marine grade hose....maybe those -8 AN are too small if your pump has poor pressure output ?
If you aren't generating pressure in the block the steam pockets may not go away, that is the point of wanting pressure, so you can be positive that there are no steam pockets.
Im running -10 from the pump, through a regulator to a "Y", 2 -8s out of the "Y" & 2 -8's out of the manifold. I still have some fine tuning to do as I am only generating 10lbs max pressure and am looking for 20-22 lbs in my application. I likely will need to run some restrictors in the exit lines.

[gqchris]

gqchris, put the gate valve between the pump and the motor and open it all the way. If you persist on playing with a restriction on the exhaust side of the motor you will sooner or later put water in the oil and blow gaskets.(usually intake manifold). Don't know why you're getting steam but my guess would be you have a restriction somewhere in the line between the pump and the block.
Did you reuse the same lines as before? If you are running a thermostat-> did you put it in backwards? If you are using SS braided lines make sure they are clear of any lil cut pieces of rubber, etc.
Brendellajet, same advice as above. If you are only running 10lbs of pump pressure then your problem is either you are bypassing too much water or if you are not using a bypass schematic then your regulator is not set correctly(or could be the wrong type). If 10 lbs is all your pump is capable of generating then you need to go thru the pump.
Do it correctly guys or do it again.
Rio
Thanks for the info Rio. I dont like that exit valve myself either. :mad:
No thermostat.
Reused the same lines, yes they are stainless, they looked good but I will relook at them in the morning.

[gqchris]

I have a dump right after the inlet of the pump to cut presure down with a gate valve. Coming out of the T are the lines the exact same length ?
-
You need to have a way to shut the water down to the headers.
That is fine.
Hey Jim, thanks so much. So place another valve coming out the manifold to the Basset t? What valve would you suggest?
I do get alot of water coming out of my headers at cruising speed, enough to where you can see actual water. I know its supposed to only be steam, I think thats where I need to look at also.