Moyer Marine Atomic 4 Community - Home of the Afourians

Moyer Marine Atomic 4 Community - Home of the Afourians (https://www.moyermarineforum.com/forums/index.php)
-   Cooling System (https://www.moyermarineforum.com/forums/forumdisplay.php?f=18)
-   -   Cooling system improvement (https://www.moyermarineforum.com/forums/showthread.php?t=12047)

2dogsnight 09-07-2021 12:45 PM

Cooling system improvement
 
2 Attachment(s)
motor temperature gets up to140-155 degrees....my oil pressure goes from 50 down to 30 at 1200rpm and speed 5-6 mpg. Looking into a way to get some more air / water, giving some extra cooling capabilities to my old motor.
The ideas are:
- install an air intake pipe from the front of the windshield to the motor box
- make windows that can be opened
- look into getting improved water pump - what is the model of my water pump??!
- ....any more ideas??

My new alternator is working great!! Very thankful to everyone for your help!!

Surcouf 09-07-2021 12:47 PM

140-150F and 30 psi are (very) good values... why would you want to go lower? It may hurt your "mileage".

Great boat by the way :)

2dogsnight 09-07-2021 01:26 PM

1 Attachment(s)
because I feel that the motor is so hot that the heat will melt all wires and hoses. Most the time I have the lid off the motor box, trying to get the heat out of there. I must add that this is my first year using the boat everyday for short runs. Finally managed to install the hour counter and have recorded 3.5 hours on it so far.
So basically I am learning the motor and the boat. With 25HP motor this boat should be going up to 17mph, and I had her going at that speed. But when motor gets to 150's she will not go that fast. Could be because of tidal currents or.......? I don't see any smoke coming out of exhaust, so the motor is strong. So I'm trying to make sure that all systems are working correctly.

joe_db 09-07-2021 02:04 PM

The boat starts at 17 knots and then slows down?

140-150 degree temperature and 30 PSI oil pressure are well within the norms of this engine.

JOHN COOKSON 09-07-2021 02:16 PM

Venting the area around the engine will help dissipate the heat that is generated.
The running temperature of the engine is determined by the engin's (correctly working) cooling system not the ambinate temperature.
Maybe the packing is a bit tight or the exhaust system is not up to the job or ?. This is not meant to be diagnostic - I'm just guessing here........


ex TRUE GRIT

2dogsnight 09-07-2021 03:24 PM

Starting at 5mph and rarely go faster. Tonight will do some testing.
Exhaust is fine I believe, but shaft packing is tight, maybe too tight. I will loosen the nut some more.....just installed new packing a month ago......not getting any drip yet! The nut temperature started at around 140 deg, after few nut adjustments is down to 110........but still no drip!!!! .....

edwardc 09-07-2021 04:14 PM

The nut and shaft should be 10-20 degrees F above the ambient water temp. Keep loosening.

2dogsnight 09-07-2021 05:01 PM

1 Attachment(s)
Will do Edward!
Have a hope that with this Forum help I will have my motor fine tuned and running like a clock! :)
I have been drooling over Sam Devlin's trawler designs (20 to 25 feet), but truly my little Fontana is plenty a boat for me........ just want it to have reliable motor.

sastanley 09-07-2021 06:14 PM

Does anyone know if the Moyer flange pump would fit on an early model? 2dogs, it definitely pumps more water..Also an Oberdorfer 202m7 should pump more water too..You could also run the bilge blower and see if it helps with engine box temps.

JOHN COOKSON 09-07-2021 06:41 PM

The new packing is settling in. You will need to continue to adjust the packing nut until it is "broken in" all the way.
I used to approach packing by adjusting the nut until I get the drip rate I like* then if the packing gland is not at or slightly above the water temperature I know is time to repack.
*one drop every 10-15 seconds for me
I once had a gutsy mechanic help me once. We started the engine and ran it up to ~1500 RPM in gear and he adjusted the drip rate while the shaft was turning! his fingers not mine.

ex TRUE GRIT

2dogsnight 09-07-2021 07:30 PM

Thank you for the ideas coming in!!
John - I hate the idea of water coming in to the boat for any reason. I would have to come up with a way to contain the drip......when I'll get it :) One thing I didn't do was to clean and lubricate the shaft before installing new packing. Newbie!
Shawn - I was looking into a bilge blower already. Feels like should help.
When I was working on motor, Moyer guys told me to leave the pump alone if is working. So it still does work :) I have the same questions as you are posting here regarding the water pump. Wander if the impeller needs changing or is it a metal one..??! I mean water is going trough the motor fine, but would be good to have more :)

JOHN COOKSON 09-07-2021 09:45 PM

Quote:

Originally Posted by 2dogsnight (Post 126873)
John - I hate the idea of water coming in to the boat for any reason. I would have to come up with a way to contain the drip......when I'll get it :) One thing I didn't do was to clean and lubricate the shaft before installing new packing. Newbie!.
Wander if the impeller needs changing or is it a metal one..??! I mean water is going trough the motor fine, but would be good to have more :)

If by chance the shaft is scored where the packing contacts it the packing will never be right.

Water is going through the engine or around the engine via the bypass? By removing the thermostat and putting a valve on the bypass you will be sure all the water is going through the engine.
The impeller is rubber.
If you want a good summary test of the water pump and strainer attach a hose to the pump output, start the engine, and rev it up briefly. The water output should be like a garden hose.

ex TRUE GRIT

2dogsnight 09-07-2021 11:06 PM

1 Attachment(s)
Quote:

Originally Posted by JOHN COOKSON (Post 126875)
If by chance the shaft is scored where the packing contacts it the packing will never be right.

Water is going through the engine or around the engine via the bypass? By removing the thermostat and putting a valve on the bypass you will be sure all the water is going through the engine.

ex TRUE GRIT

well, the last packing material had a graphite in it and shaft had black residue on it, which I didn't remove/cleaned.

no idea where the bypass is - will be looking for that. I believe my motor does not have a thermostat. I had this thing in pieces during rebuild. Then again it was few years back and my memory is not what it used to be.

Went out on the boat, turned back one turn ( 1/3 at the time), no drip. Temperature still 110 /140
Speed test didn't work the way I hoped. Motor was very happy at 1000 rpm, 6.5mph....full throttle produced max speed of 8.2 mph.
Something is not right

sastanley 09-08-2021 10:30 PM

2 dogs...looks like a grease cup on that bracket forward of the packing.
For testing, you need to be willing to experiment, but don't too many things at once.

One test may be to set the packing way loose and let some water in to see if it makes any difference (I doubt it) and different throttle settings. The next thing I would check is things like timing. If the water temp is OK, then getting the heat out of the engine box are two different problems.

We just need to focus on your goals and knock them out one at a time. :cool:

2dogsnight 09-08-2021 11:46 PM

thank you Shawn,
I read Moyer Atomic 4 book I have, looking for answers, also learning about shaft packing.

Cooling system in my motor does not have a thermostat or coolant bypass.

Tomorrow I will take the packing nut out ( at low tide, sitting on tide land), will clean the shaft from graphite, use some light coat of grease on shaft before installing new packing. Packing nut temp. should be 30 - 40 deg over the cooling water temp, so no more than 100 deg. Packing nut should be hand tight to start. Interestingly no need to have water dripping out of packing nut as long as nut temperature is not more then 30-40 deg more than water

Will make small adjustment to oil pressure with spring loaded relief valve. According to the book oil pressure should be 40psi........oil pressure is slowly getting lower from 50psi down to 30, will go back to 40 with higher throttle, but after few minutes will go back down

I don't suspect that the timing is not right, as I have the boat going 17mph a week ago

.....starting thinking about getting an outboard again ......

Surcouf 09-09-2021 12:57 PM

Quote:

Originally Posted by 2dogsnight (Post 126889)
Will make small adjustment to oil pressure with spring loaded relief valve. According to the book oil pressure should be 40psi........oil pressure is slowly getting lower from 50psi down to 30, will go back to 40 with higher throttle, but after few minutes will go back down

Check the site poll on oil pressure: You are right on the sweet spot of that engine. Unless something else alarms you, there is likely nothing to do on oil pressure.
https://www.moyermarineforum.com/for...ead.php?t=3333



Regarding your packaing, you are bang on: if it does not overheat, and does not leak... why touch it? like you say in the US "if it ain't broken..."

Is your original concern your max boat speed, and why you cannot go faster? this is much more likely a prop & hull discussion than an engine one, as long as your engine goes up in rpm (which it does for now according to what you were saying)

2dogsnight 09-09-2021 01:09 PM

Quote:

Originally Posted by Surcouf (Post 126896)
Check the site poll on oil pressure: You are right on the sweet spot of that engine. Unless something else alarms you, there is likely nothing to do on oil pressure.
https://www.moyermarineforum.com/for...ead.php?t=3333



Regarding your packaing, you are bang on: if it does not overheat, and does not leak... why touch it? like you say in the US "if it ain't broken..."

Is your original concern your max boat speed, and why you cannot go faster? this is much more likely a prop & hull discussion than an engine one, as long as your engine goes up in rpm (which it does for now according to what you were saying)

I will have the boat on the "soft" in few hours (sandy tidal beach :) ) hopefully will get some answers

2dogsnight 09-09-2021 11:16 PM

3 Attachment(s)
took "old" packing stuff out. Cleaned shaft with 220 and 800 grit paper. Cleaned nut inside and installed new packing.

used very little of marine grease to lubricate the shaft where the packing material was going to be. Then added a drop or two of engine oil ( I know, but I was desperate to make this work). Tightened the nut by hand.

First 10 minutes the nut was in 80's, after 20 min I was getting readings anywhere from 90 to 120 degrees. Shaft was in 80's up to a foot from the packing area......more than a foot the shaft was cool to the touch

Motor was running good, oil pressure was 40psi all the time.

Boat has stuff growing ,so that is slowing her down.
Tomorrow will have to make that packing weep :) , need to have water going trough it. Maybe I have too much of packing material? There was very noticeable difference in friction between one and two packing rolls in the packing nut.
Need shaft lubricant !! ??

joe_db 09-10-2021 08:36 AM

I think the seaweed is the problem here :eek:

joe_db 09-10-2021 08:52 AM

Can I suggest you get a Moyer manifold pressure gauge? It makes it quite easy to detect issues that load the engine like a foul bottom or bad stuffing box.

https://www.moyermarineforum.com/for...1&d=1589803874

edwardc 09-10-2021 09:41 AM

Quote:

Originally Posted by 2dogsnight (Post 126900)
... Maybe I have too much of packing material? There was very noticeable difference in friction between one and two packing rolls in the packing nut...

Aha! I think we have a clue. You probably have the wrong diameter packing, rather than too much. Properly sized packing should take three rings of packing. I had something similar happen when I tried to use 1/4" packing on my system. It got hot, and even with the nut hand loose , it wouldn't drip. Dropped down to 3/16" and everything worked as its supposed to.

2dogsnight 09-10-2021 11:46 AM

Ed, I am going to get 3/16 packing and shaft lubricant and re do packing again. This is very exiting!!!! I think you're right, especially that you've same experience!!

Joe, the only gage I don't have is vacuum.

So I am thinking that the shaft packing along with growth on the bottom causes max speed drop. We will find out soon.

Now off to find 3/16 packing material and shaft lubricant.

Thank you guys!!

edwardc 09-13-2021 10:25 AM

I found this mini pick set to be very useful in digging out old packing:

https://www.harborfreight.com/mini-p...set-63697.html

W2ET 09-13-2021 11:17 AM

Somewhere on this forum is a link to a very well done video on how to do this.

How to cut the strips, how to orient them versus one another, etc. I remember that the site had a bunch of great content, including how to rebed stanchions, and more.

Bill

Surcouf 09-13-2021 11:28 AM

Quote:

Originally Posted by W2ET (Post 126918)
Somewhere on this forum is a link to a very well done video on how to do this.

How to cut the strips, how to orient them versus one another, etc. I remember that the site had a bunch of great content, including how to rebed stanchions, and more.

Bill

https://www.boatus.com/expert-advice...a-stuffing-box
https://www.moyermarineforum.com/for...packing+change


All times are GMT -4. The time now is 03:32 PM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved