water in oil from exhaust?

[afsam94]

This is started by suggestion from Afourians in the Good Guys section.

Chocolate milk oil issue SEEMS to be resolved following addition of Barrs Leak to fresh coolant. Adding this stuff was a last ditch effort after rebuilding freshwater pump and a good pressure test failed to resolve the issue or point to a crack in the block. But I intend to travel the intracoastal to Florida from Maryland and I don't trust my $8 dollar Walmart Barrs Leak solution...nor does Don Moyer....nor Ken....nor Whippet...nor any sane person I've spoken to.

Whippet suggests back up of raw coolant from the (admittedly jury rigged whacky) exhaust configuration into the engine could be the cause of water in the oil. Note YES I'VE SEEN WATER SQUIRTING OUT OF THE LAST CYLINDER WHEN PLUG WAS OUT AND YES I HAVE SEEN WATER GUSHING OUT OF THE CARB. But I resolved that issue by another whacky set up comprised of a ball valve after the raw water in bound through hull that I 1) open immediately AFTER the engine is running and 2) close immediately BEFORE I shut off it off.

You will see my exhaust system in pictures by 2pm this afternoon. It is as screwy as it is because when I removed asbestos (10 years ago?) I put in the plastic muffler you will see behind the stuffing box and removed the canister that was far back and high in the stern. You will also see that I left the high loop in the exhaust because I THOUGHT I needed it. please wait for pictures to reply. Again engine is running smoothly with no chocolate milk oil at the moment.

Note that this exhaust pipe comes straight out of the minifold (no loop before the water enters). I intend to wrap it with insulating tape later today.

[Whippet]

Don Moyer Wisdom

I couldnt find easy way to just give the link - but below is old post from our leader about water in oil.

Ken (parts) over time has confirmed that most frequent cause of water incursion in oil is sourced from exhaust (can happen from overcranking, healing, improper lift design). I've been there - and I think exhaust was my cause. A prevention i now take is to shut off raw water intake a few seconds before i shut down engine just to make sure there isnt an exhaust full of water. i have even purchased larger water lift muffler (yet to install) for extra margin of safety.

if you really want to rule out cracked block / manifold, pressure test procedure is outlined below. That gave me comfort when test passed.



Hello Mwebb,

Not to undermine the well deserved confidence you have in your local mechanic, but here is a technical note that we prepared recently to assist folks who discover water appearing in their oil when there is no evidence that it is coming in via any of the combustion chambers:

Whenever water is discovered to be only in the oil, we recommend that the oil be changed at least three times before moving ahead to more serious troubleshooting. If the oil cleans up, we make the assumption that weather conditions were right for condensation or that some water may have splashed into the dip stick tube, etc. We hear of several episodes each year where small amounts of water have shown up in the crankcase, for which there is never any cause found and where (happily) the water never returns.

If the oil clears after the third change and you want more assurance that there is no problem with any of your cooling jackets, you can perform a quick check of your water-jacketed castings by pinching off the water discharge hose coming off the back of the manifold for several ten-second pressure checks. A flexible impeller pump in good condition can produce 20 to 25 psi when deadheaded in this fashion. If there is a crack anywhere in the water jacketed castings, this amount of pressure will usually force water back into the oil at a rate that should be unmistakable.

If small amounts of water do continue to appear in the oil after the third oil change, we recommend checking the following items (admittedly rather long shots) before moving on to more serious maintenance:

1) Inspect to see if a Sherwood or Jabsco water pump is installed on the engine. Both of these brands have the potential of passing a bit of water into the crankcase if their water seals leak and the weep holes in their housings become plugged with grease and crud. In this scenario, trapped water along the shaft of the pump can force past the second seal (the one preventing oil from coming out of the crankcase) and into the oil pan. Oberdorfer and MMI flexible impeller pumps have large weep holes in their housings, so they don't have this same potential.

2) Remove the valve cover to inspect for water entering into the valve chamber through a hole in the very center of the water jacket behind the valve springs. In some of the later model engines (usually with serial numbers over 194,000), Universal used a 1/4" pipe plug to close a hole in that area. The problem is that they used plain steel plugs which have a strong potential to fail after the 25 or so years since they were installed.

If no other cause can be found for water that continues to appear in your oil, we would have to suspect a crack in the lower part of the water jacket within the block. The easiest way to pressure test the block (without removing the head) is to first plug the outlet of the thermostat housing. Then remove the hose from the outlet of the water pump, and install a Schrader valve in the end of the hose, so that a standard bicycle tire pump with a built-in pressure gauge can be used for the test. A Schrader valve is the standard valve used on automobiles, and they are available at any auto parts store. The block should be able to hold 20 psi for an hour or more without a noticeable drop in pressure.

If you have an early model engine, you can perform a pressure test on your early model engine using a bicycle pump with a built in pressure gauge as follows:

1) Remove the water fitting from the inlet to the water jacket side plate, and install a 1/4" pipe plug in the inlet. If you have previously replaced the 3/8" metal tube between the pump and the side plate with a rubber hose, it may be easier to remove the hose from the outlet fitting of the pump and install a plug in the end of the hose for the test.

2) Remove whatever fitting is installed in the outlet of the manifold, and install a reducer bushing and a Schrader valve in that location.

3) Pressurize the block, head, and manifold to 20 psi. The cooling jackets should be able to hold 20 psi for an hour or more without a noticeable drop in pressure.

Best regards,

Don Moyer

[afsam94]

I followed every step outlined and the pressure held in two separate tests.

I followed every step outlined in that missive and the pressure held in two separate tests.

Note Don went so far as to mail be a rebuilt fresh water pump but I never used it and returned it because the Barrs Leak SEEMED to fix it.

adding more pics of exhaust and I will add notes about the pics.

I have only been able to post one of my pics so far. You can see the exhaust pipe comes straight out of the manifold (no loop before the water enters). I intend to wrap it with insulating tape later today.

[joe_db]

That exhaust looks designed to flood the engine

[afsam94]

All additional uploads of pictures failed

All additional uploads of pictures failed.

Yes water was backing into the engine until I put the raw water valve in as mentioned above.
Before I put in the raw water control I ran it this way for years even though I did experience water backing up I could stop it at the raw water through hull.

No water in oil or other problems CURRENTLY

[ndutton]

That one picture was all I needed. You really should search the forum archives for everything you can find on exhaust systems.

[joe_db]

FYI - this is a very crude drawing of how it is SUPPOSED to be set up. There are variations, for one example my raw water goes in the top and an internal 1/2" copper pipe goes down a few inches inside the exhaust pipe.

[Ram41662]

Afsam...here is my exhaust system, set up outside the boat on a test bench.

You can see the vertical rise from the exhaust manifold and where the water line attaches to the mixing manifold before dropping to the water lock.

This is all shortened up because it is on a test bench, but it is the same configuration that was in my boat.

This basic configuration is pretty standard. Without the rise and the water lock, water will back up into your engine.

Rick

[zellerj]

Ram,

Except the water injection point should be downhill towards the water lift from the top of the U. Otherwise without exhaust pressure (that could happen with a no-start scenario) cooling water could go right instead of left and end up in your exhaust manifold and into a cylinder.

Is there enough exhaust pressure created from a non-starting cranking engine that would prevent reverse water flow into the exhaust manifold?

I am pretty sure cooling water would flow or else we would not be so careful to warn about flooding a water lift muffler on hard-to-start engines.

Edit - sorry Ram, just realized that the turquoise piece must be a short heat exchanger so that the cooling water will not mix with the exhaust gases until further down the slope.

[Ram41662]

Jim,

No problem, I thought that too when I first saw this set up. It looked like the water was more likely to go back to the engine than out of the boat. Once I disassembled it I saw what was actually going on in there.

Yes, the part past the insulation is a mixing manifold for the coolant water and the exhaust gases. There is a set of baffles and an inner tube in there that prevents that water from flowing the wrong way. I'm not sure how long I'd have to crank the motor to allow water to back up through this device. Honestly, I don't think it would flow back to the engine unless there was a blockage.

My point was as long as the exhaust is straight and near or below the water line, I can't imagine a scenario where water wouldn't eventually back up into the block.

Rick

[afsam94]

Yes its a ridiculous exhaust configuration. Yes it works without back flow

Thank you.

Absolutely there should be a rise and a drop in the exhaust pipe immediately after it leaves the exhaust manifold before the raw water coolant (in my case) enters. Every diagram that I have seen over the years shows it and every atomic four owner I have spoken to over the years has said it is an absolute must or water will flow back into the engine when you start it or stop it.

As I said I never start the engine with water flowing into the exhaust...for a few seconds only hot exhaust gas comes out of the stern. I only open the ball valve for raw water coolant to flow into the exhaust AFTER the engine is running so exhaust pressure forces the water down to the muffler and on preventing water from any back flow AND I never turn the engine off without first closing the the ball valve so for a few seconds of hot engine exhaust pushes the the remaining water out the stern.

So as I said the whacky setup works without back flow as long as nobody in the universe besides me tries to start my engine. If they do without understanding the absolutely insane bass ackwards ball valve push pull operational theory behind this ridiculous setup they will either flood the engine (with water) or melt the muffler. Whew!

Pros I asked about fixing the configuration either declined because they said its too much hassle to cut and thread my fragile straight pipe and or they said if they snap it off they wont by me a new manifold. I've thought about doing it myself but it works so why bother.

My real question here is was the water in the oil last year both before and AFTER I added the ball valve (when I am sure there was no back flow) the result of a crack in the block or something else? And why did Barrs Leak seem to fix it so she purrs now with no water ever appearing in the oil? (The jackass straight pipe exhaust has served me for at least ten years since I took the asbestos out and serves me now. I will put insulation tape around it tomorrow which is another aspect Ive been lucky with. I had insulation on it but it was the wrong kind and burned up)

See raw water ball valve after start open before shut down close device below.

[ndutton]

Please forgive me

It seems to me that you're trying to do anything and everything BUT doing it right. You might not get water up the exhaust this time or maybe next time but mark my words, that exhaust WILL ship water into the engine at some point. It probably already has in its history and will again. When it does, besides cleaning out the goo from the engine again you're looking forward to a future of sticking valves, hard starting and poor performance.

Have a look at the Moyer Marine online catalog. In the exhaust section you'll find a complete exhaust hot pipe. Check if the dimensions will fit your boat.

[afsam94]

You mean

https://moyermarine.com/product-category/exhaust/

and

https://moyermarine.com/product/manifold-late-model-aftermarket-ovcm_02-0_303/

I may do that

But its a lot of work and expense if there is crack in the block and I actually need a new engine.

I understand about doing it the right way but I'm afraid I may be doing the the wrong project the right way. And if I need both a new engine and new exhaust we may be getting into an area where my partner could pull the rip cord. Really thank you to all. Sometimes I forget how many times you and and MMI have helped me and I do appreciate it.

[Whippet]

Basic Exhaust Design

Typical (but not only) exhaust design. See attached pdf

I believe this is also in Moyer manual - that you should get if you dont have

[ndutton]

Believe me, I understand. However, the only thing that would be worse than keeping that exhaust with this engine would be connecting it to a new engine.