Changing Engine Oil on the hard

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Jun 7, 2004
99
Catalina 309 Ottawa
My boat is on the hard now and I want to change the engine oil. I need to run the engine ( a Yanmar 3YM20) long enough to warm up the oil. Since access to the raw water intake through hull is limited and would only provide a very short hose to tap into I was planing to feed fresh water into the engine by fitting a hose to the external raw water intake port on the exterior of the hull.

I have found that a flexible hose with a 1/2" exterior dimension will fit very snugly into the raw water intake port on the exterior of the hull. I don't want to feed water to the engine under pressure, so I was going to place the other end of the 3' hose in a 5 gallon pail, fill the pail full water, raise the pail to a level even with the raw water intake port and let the engine draw in fresh water that way. Water in the pail would be replenished from a second hose connected to a water tap. Once the engine was at operating temperature I was planing to empty the water from the pail and put in a couple of gallons of antifreeze and continue running the engine until the antifreeze came out the exhaust.

My question is will the raw water pump on the engine be able to draw water into the engine using this set up? What would the pros and cons of such a set up be?

Gary
 
Oct 22, 2008
3,502
- Telstar 28 Buzzards Bay
I wouldn't recommend that... since the pressure of the hose may be greater than that of the water pump draw, and the water would be forced through the water pump...which is bad for the pump.

What you should do is run a hose from the water intake into a bucket, and then put a hose from the water supply into the bucket. This way, the engine can draw water at its own rate, without abnormally high pressure feeding it. Put the bucket at the same level as the intake through-hull so that the head the engine water pump has to deal with is roughly the same as if it were in the water.

This is probably easier to do inside the boat than from the outside, and having a "t-fitting" on the water intake line or removing the water intake line from the through-hull is probably the simplest way to accomplish this, with the bucket sitting somewhere in the bilge.

Since you say access to the hose on the interior of the boat is limited... now might be a good time to add a diverter valve. This diverter valve will make winterizing the engine in the future much simpler, so would probably be a worthwhile investment to make.
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
My boat is on the hard now and I want to change the engine oil. I need to run the engine ( a Yanmar 3YM20) long enough to warm up the oil. Since access to the raw water intake through hull is limited and would only provide a very short hose to tap into I was planing to feed fresh water into the engine by fitting a hose to the external raw water intake port on the exterior of the hull.

I have found that a flexible hose with a 1/2" exterior dimension will fit very snugly into the raw water intake port on the exterior of the hull. I don't want to feed water to the engine under pressure, so I was going to place the other end of the 3' hose in a 5 gallon pail, fill the pail full water, raise the pail to a level even with the raw water intake port and let the engine draw in fresh water that way. Water in the pail would be replenished from a second hose connected to a water tap. Once the engine was at operating temperature I was planing to empty the water from the pail and put in a couple of gallons of antifreeze and continue running the engine until the antifreeze came out the exhaust.

My question is will the raw water pump on the engine be able to draw water into the engine using this set up? What would the pros and cons of such a set up be?

Gary

Should be fine as long as you have a decent impeller. Just don't put the antifreeze in until after you've changed the oil and run the engine up to pressure for a minute or two to circulate the new fresh oil throughout the engine and checked the level on the dip stick..

If you are going to run the engine like that be sure it has been run for a while to burn off the condensate that forms on cold weather start ups.. Seeing as you can't put her under load this will take longer than when in the water.

I wouldn't recommend that... since the pressure of the hose may be greater than that of the water pump draw, and the water would be forced through the water pump...which is bad for the pump.
Dog,

The way I read it that is not what he is doing. It sounds as if he's found a plastic hose barb or other fitting that will press fit into the thru-hull (could fall out due to vibration though) and that runs into a bucket which is then fed by a hose. It does not sound like he's pressure feeding it which, as you know, is a big NO, NO..
 

Scott

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Sep 24, 1997
242
Hunter 31_83-87 Middle River, Md
It's easier to just pour water into the strainer either with a bucket, jug, or hose with a valve on it to regulate flow.

Scott
S/V Common Ground
 
Oct 22, 2008
3,502
- Telstar 28 Buzzards Bay
Farley—

Not for the period of time it will take him to warm the engine up...and then he will have to change the oil and then run the engine to get the new oil spread through the engine.... and then add antifreeze to the cooling system.

Also, trying to do that in some engine compartments, assuming you're talking about the raw water strainer, will cause a mess, since they're sometimes mounted lower than the engine intake hose... and doing it with a bucket or jug would require two people more likely than not.

Having the bucket and hose setup simplifies this a lot, since he doesn't have to mess with it once it is setup and to winterize the engine, all he has to do is fill the bucket, provided it is large enough, with antifreeze... and have the engine suck it up... :)
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
It's easier to just pour water into the strainer either with a bucket, jug, or hose with a valve on it to regulate flow.

Scott
S/V Common Ground
My engine can suck a five gallon bucket dry in 50 seconds at 1200 RPM.. Are your really going to stand there and keep up with these flow rates for a half hour to 45 minutes while your engine comes up to temp enough to burn off the condensation?

Also hoses make huge wet messes when fed into a 1/2 gal capacity stainer at street pressures that run between 70 & 100 PSI. Add a valve and now you've created lots of air that your impeller will be sucking in.

You NEVER connect a hose directly to a raw water intake I hope!

Using an in/out bucket is EASY!

Hose to in/out bucket:


Feed hose & engine intake hose (the clamps help keep the hoses in place):


Setting up an in out bucket takes less than a minute and a half.

A) Close seacock if you are still in the water.

B) Loosen the two hose clamps on the intake side of the strainer.

C) Pull off the hose.

D) Connect hose to in/out bucket and snug up with one hose clamp.



Running the engine:


1) Start engine & then very quickly stick hose to bottom of bucket and make sure the hose primes.

2) Run engine up to full operating temperature and leave it there for at least 15 minutes once fully warm.

3) Pull hose from bucket then within a few seconds pull the stop lever.

4) Change oil

5) Run engine again and shut down following 1,2 & 3 from above.

6) Check oil level, if low add some to get it close to full, but never over fill. Allow it to drip back to the oil pan for up to 30-40 seconds before checking the oil level. This will ensure you don't over fill.

7) Check the sealed side of the antifreeze with a hygrometer for freeze protection. Address this issue if the freeze protection is not suitable for your area.

8) Fill bucket with non-toxic engine rated antifreeze. It has more corrosion inhibitors than the pink stuff you use for the fresh water system & is usually rated in 60 & 100 below strengths.

9) Start engine following #1

10) let engine suck in all the antifreeze and shut down once the bucket is empty.

11) Remove the impeller.


Done..
 
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Oct 22, 2008
3,502
- Telstar 28 Buzzards Bay
And by having the bucket in the cockpit as Maine Sail shows in his photo or outside the boat on a ladder, any overflow from the bucket ends up outside the boat.... much less messy. :)
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
Some words of caution:


#1 If your bucket is located higher than your engines siphon-break, the OP's won't be, NEVER, DON'T & DO NOT shut the engine off without pulling the intake/sea strainer hose from the bucket and letting it suck dry or down below the level of the siphon break!!

Always pull the hose and let the impeller suck the remaining water from the hose before shutting down the engine.

Why?

If your bucket is above the engines siphon break your engine can, and will, fill with water and you will hydro-lock it. This is NOT good and will require many, many oil changes, like seven to ten, with filters, to get rid of all the water in the engine. It may not happen the first time but it will and can eventually happen.

Please do yourself a favor and remove the hose from the bucket before you shut down if your bucket is ABOVE the engines siphon break!!!

Raw water pumps are NOT valves, are NOT a positive shut off and they do not stop gravity or siphoning. If your bucket is above the engines siphon break it will siphon and you can and will eventually have a hydro-lock situation where your cylinders fill with water.

If you do this in the cockpit, as most of us do, there is a very high likely hood that your engines siphon break is below the siphoning level of the bucket.. Pleas be careful.

#2 Never, ever connect a garden hose straight to your engine. The street pressure will not only blow out the seals of the water pump but within in seconds, even when running, it can hydro-lock an engine. Municipal water supplies can have street pressures as high as 100 psi. Use an in/out bucket to avoid serious damage!

This is an engine siphon break. If your in/out bucket is higher than the siphon break it can not break or stop the siphoning!!!! Pull the hose before shut down!!!

 
Jun 7, 2004
99
Catalina 309 Ottawa
Thanks for the confirmation and the advice regarding my proposed method. If I can get my setup to work it will be easier than installing a T-connector on the raw water hose inside the boat. By keeping the bucket outside the boat, elevated on a ladder so that its just below the engine, there is no danger that it will be higher than the siphon break. I really appreciated this last piece of advice. The biggest downside to my proposal is that it will definitely require 2 people to monitor the setup. I will use clamps to ensure that the hoses remain in the bucket. With my small engine I expect that the engine will not draw water faster than the hose can fill the bucket, but I will be watching carefully. Next season I will change the oil while the boat is still in the water as it is just easier that way. Then I'll only have to add the antifreeze to the raw water system when the boat is on the hard. This is my first year with a boat with an inboard engine so I'll chock this up to lessons learned.

Gary
 
Sep 25, 2008
544
Bristol 43.3 Perth Amboy
Added benefit of a t placed in salt water intake

An added benefit of a T placed after the salt water intake is the ability to use you engine as a bilge pump in an emergency. Just remember to have a screen over the end of the hose.
 

Bob S

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Sep 27, 2007
1,797
Beneteau 393 New Bedford, MA
Question to Mainesail

Do you repaint your engine every year? Where's the dust? I have a little rust starting around the coolant cap that I want to touch up. The boat comes out tomorrow. :cry:

I noticed your alternator is the same color. Was this the Leece Nevelle 90 amp you have on your boat project website?
 

Ross

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Jun 15, 2004
14,693
Islander/Wayfairer 30 sail number 25 Perryville,Md.
If the bucket will be off boat someone should tend to the bucket. Gary's set-up isn't good for a one man job. There is nothing wrong with it otherwise.
 

Bob S

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Sep 27, 2007
1,797
Beneteau 393 New Bedford, MA
Last fall I had the bucket inside next to the engine. I needed a body to turn the hose off when I was done because the shut off was too far away and it would have overflowed into my bilge. In the spring I added a shut off on the end of the hose so I could regulate the flow into the bucket = to the flow drawn out. It work much better and it became a one man operation.
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
I do keep it clean..

Do you repaint your engine every year? Where's the dust? I have a little rust starting around the coolant cap that I want to touch up. The boat comes out tomorrow. :cry:

I noticed your alternator is the same color. Was this the Leece Nevelle 90 amp you have on your boat project website?
I do keep it clean and as rust free as possible as they are very, very expensive. I do also re-paint areas that need it but the engine is 90% original paint. I keep it clean so I would notice any leaks right away and also any signs of rust.

I've owned many, many boats and this is a new one to us, only two years hence the numerous alternator upgrades..

She has the stock Westerbeke alternator and spent 5 years, full time live aboard cruising, mostly on the hook using only this stock alternator and an 80 watt solar panel. She was in the Carib, South America and all over where it's very hot and warm and had no temperature compensation or fancy charging devices. The PO, a friend of mine, got five years out of the wet cell batteries living 24/7/365 on the boat while cruising. I replaced them when I bought the boat because I knew they were five years old my personal cut off. Who knows they might have gone six or seven+..?

The alt worked well for him, with the solar panel, and it has worked for me for the last two years. I see no need to go bigger, it's 72 amp, and have really moved away from the "smart regulators" for a few reasons, namely failures.

I don't doubt their usefulness, in certain situations, but I replace my batts every five years regardless so the "gain" would be marginal at best for me...

BTW our 2003 engine now has 2800 hours on it from making numerous trips up and down the ICW and to run the engine driven refrigeration while she was cruised. 2675 hours, what she had when we bought her, of charging the same wet cell bank, with a "dumb" regulator, and the batts still lasted five years!

Hope this helps answer the confusion. I still think the Leece Neville alts are a great replacement for the stock 51 amp alts on the Universal engines. I installed two of them, on two different boats, only the second time I did not do external regulation.

Sorry for the hijack. Now back to our regular scheduled programming..!
 
Last edited:
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Donig things the hard way

Guys!
It is not essential to warm an engine to change the oil!!!!
IF GKuffner had a really bad old contaminated oil problem then yes a warm engine would help but from his comments about keeping it clean he is apparently doing regular oil changes and does not have a "sludge" problem.
Just drain (best but not always possible) or suck the oil out and change the filter!!!
The major thing you are trying to get rid of with an oil change is the acids in the oil pan that are produced during combustion, stay their all winter and corrode your oil pan.
If you are trying to get the "film" oil out of the bearings so the acid does not effect your bearings, good luck! Heating up the oil will not do that. Letting it drain for a long period of time will however. Like when the engine has not been run since you hauled the boat out.:D
A COLD oil change will suffice IF you do them regularly.

I never run the engine before an oil change but do do them every 50 hours. Who wants to deal with hot oil anyway??? The job is a pain and you want to add hot oil to deal with. REALLY not neceassary!!!!

OR you could heat the oil with a propane torch after you sucked it out if you really wanted to have hot oil to deal with.:dance:
 
Feb 26, 2004
22,986
Catalina 34 224 Maple Bay, BC, Canada
Confused about hose shutoff

Get a cheap ball valve at a hardware store and stick it on the hose before the nozzle. No more "shutoff valve too far away."
 
May 11, 2005
3,431
Seidelman S37 Slidell, La.
Ross, I'm surprised

Why would you use a gate valve. The plastic ball valves at Home Depot are at least cost comprable, and much more reliable.
 

Ross

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Jun 15, 2004
14,693
Islander/Wayfairer 30 sail number 25 Perryville,Md.
Why would you use a gate valve. The plastic ball valves at Home Depot are at least cost comprable, and much more reliable.
Not a gate just a 2-3 turn compression valve. Lets me controll the flow better than I can with a ball valve.
 
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