verifying raw water flow

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
D

Dawdler

Senior Member
Joined
Jul 20, 2014
Messages
189
Location
USA
Vessel Name
none
Vessel Make
pipe dream
my genset has an underwater discharge for the raw water. I'm concerned that there isn't an easy way for me to see whether I'm getting coolant flow. Has anyone come up with a good solution to visually check that the raw water pump and heat exchanger are performing ? Appreciate any suggestions.
 
Last edited:
Coolant.... or raw water? Aqua alarm is good for raw water.... Murphy gauge is good for low coolant
 
I have a Borel alarm installed on both main and the genset exhaust. It measures the exhaust temperature right after the cooling water is injected into the exhaust stream. If the water pump stops working, this alarm is supposed to,go off immediately before the engine temperature gauge shows an overtemp. I also have 2 high water alarms and water in fuel sensors in the system.
 
Thanks both for your replies. It's the raw water flow I was concerned about. I"ll look into acqua alarm and the borel solution.
appreciate the help.
 
You can put a "T" in a hose and a small ball valve. Start the gen, open the valve and observe folw or no flow. Less than $20.
 
Take baseline full load temperatures with a handheld infra red temperature gun at key points. Find the highest temp at each point and mark it for consistent subsequent checks. Write them down so its easy to compare later without guessing. Exhaust hose, exhaust riser, header tank, thermostat housing, heat exhanger seawater inlet and outlet. The exhaust riser will heat up PDQ with no seawater flow. A quick check using the back of your hand will tell if something is wrong.
 
Does your genset have meters to monitor coolant temperature, oil pressure, and electrical output?
 
thanks again to all. I love the simplicity of Nomad Willy's suggestion.
 
Mark,
yes, have all that. I'm just in the habit with the mains of looking at the engine exhaust ports immediately after engine start to confirm raw water flow, and was trying to be able to check the generator raw water flow as well, rather than waiting for temp alarms to go off.....
thanks.
 
Dawdler said:
thanks again to all. I love the simplicity of Nomad Willy's suggestion.
Click to expand...

Just have a way to catch and clean up the water... ever see what the flow looks like coming out of a hull-side discharge?

Is this underwater discharge just the water after running through a separator, or also exhaust?
 
While at dock or in a dinghy, perhaps you could place your hand at the outlet and get a good sense of the water flow, or would your hand be cooked?

I'm genset-less, so curious: do boaters pay as much attention/maintenance to their gensets as they do their propulsion engines?
 
Last edited:
markpierce said:
I'm genset-less, so curious: do boaters pay as much attention/maintenance to their gensets as they do their propulsion engines?
Click to expand...

I'd have to say most of them no. When we bought our boat the engines where not to bad but the genset at much the same running hours was completely had it.

When we start our genset we just monitor the engine temp once the load is on it until it becomes stable and within the normal range 160 - 185.
 
Dawdler said:
. . . just in the habit with the mains of looking at the engine exhaust ports immediately after engine start to confirm raw water flow, and was trying to be able to check the generator raw water flow as well . . . /QUOTE]

A very good and simple habit, may well save you a major overheat one day. I suggest installing a Tee in the hose which injects raw-water into the exhaust elbow. Run a small (1/4"?) line to a through-hull well above the water line and easilly visible from the deck. A good stream of sea water will be visible when the genset is running and all is well.
Click to expand...
 
I ran a 1/4 inch polyethylene line out the transom.
I simply drilled a small hole, then I glued in a piece of 3/8 copper tubing.
Passed the 1/4 inch line thru it and slightly crimped to hold it in place. Likely also sealed it with permatex gasket maker

Engine side, I tee'd it off from the raw water injection, I brazed up a copper tube to an existing raw water part, then passed in the plastic tube and sealed it with Permatex gasket maker., Or I used a short piece of rubber hose, can not really recall..

I used clear poly tubing like you can buy at Lowes as it is very cheap around 11 cents a foot..
Did that at least 5 year ago.

I did this on my main engines as I have underwater exhaust extensions, and you can not see the raw water flow.
 
Last edited:
I didn't realize how spoiled I am...
I have an old Pancake style strainer with an 8" or so clear top. It's a simple mater of lifting the engine hatch, observing the circulation and being on my way....
 
You must log in or register to reply here.

Similar threads

W
1984 Perkins 6354M Raw water exhaust issue?
Replies
1
Views
204
Turtle Blues
Turtle Blues
SeaDogAK
Heat exchanger raw water connections
Replies
11
Views
901
Lepke
Lepke
S
JD 4045 External Coolant Loop
Replies
7
Views
2K
scurvydog_pnw
S
tpbrady
Generator Overheating
Replies
27
Views
2K
Simi 60
Simi 60
J
Aluminum/Zinc Anodes
Replies
20
Views
2K
fstbttms
fstbttms

Latest posts

Back
Top Bottom