Tow valves for flushing

[WREKS]

I would highly doubt that higher pressure from cooling water would cause that kind of damage. Even 200psi water won't do that to aluminum. That looks like a cavitation or aeration burn. Possibly carbon deposits along the cylinder/head interface getting very hot and essentially creating a localized boiling point that, over time, shows the same erosion as cavitation.

There are other possibilities as well. Additional pressure is accompanied by additional velocity when looking at fluid flow through a given area. Localized accelerations of fluid could lead to erosion of the metal of very long periods of exposure, assuming there was something in the water to make it abrasive (sand, or other suck grit). This is the same concept as a water jet cutter. High pressure differential is used to accelerate water with cutting agents across the surface of a material to cut it. I could see that possibly being the case here, however the material removal appears to be non-uniform, and extremely localized. "waterjet" type erosion would more typically show as overall thinning of the walls, and not nearly as pinpoint as what is shown here.

Pressure alone won't hurt the gaskets. Combustion pressures are significantly higher, orders of magnitude, higher than cooling water pressures. The pressure must be combined with increased flow velocity to erode the metal like that. i.e. the valves are most likely NOT the cause of that sort of erosion. I would suspect bad luck with an imperfect casting in that area is more likely.

Thanks, Beachbummer! Sorry for the slow response. I was looking for a photo of the head gasket. I will go with the "localized boiling point" because where this infraction took place was where the cylinder water jackets were the most clogged. That is around Cylinder#1, the farthest from the cooling water input to the cylinder block. BTW, The return from the cylinder block is located directly above the input so in order to flush collected debris from the water jacket around cylinder#1, the water must either go back to just above where it came into the cylinder block, or up through the head gasket into the cylinder head. The holes in the head gasket act like a dead head. They are so small, not like the water passageways on either side of the gasket. At first it looks like large openings. That is where sediment collected on either side of the gasket. I do not see how ingested sand and sediment can be flushed out of the water jackets. Thus debris builds up and leads to overheat issues. While running my starboard engine on the hose the temp around Cylinder #1 was above boiling when my boat slumped into low idle

 

[WREKS]

Hey WREKS. Help me out here - it looks like the cavity is in the head rather than block/cylinder. Am I seeing it right? Probably corrosion. Otherwise I don't think the cooling water pressure could get high enough to breach the head gasket.

On my boat (2013) there is a check valve to prevent the coolant in the block from draining when the engine is shut down. Most likely to keep the engine from overheating just after shut off. If the block cannot be flushed the passages will begin to plug, which was my problem. I can easily imagine that could have caused your problem as well.

You are absolutely right, BrentEB. The head had the cavity. It has been a while. Thanks. Anyway It got over boiling temp (217F). I guess it turned to steam, got passed the rings, and condensed in the oil. But the worst is always up by Cylinder#1. I dot not see how the "whatever" can be flushed out, once it gets in.

 

[WREKS]

Thanks 2kwik4u, I meant to reply to your post;

 

[2kwik4u]

Thanks 2kwik4u, I meant to reply to your post;

NO worries. YOu did reply to my post, just called me someone else I knew what you meant.

I'm curious about the dead head space though. You don't typically see water jackets without at least decent flow paths, especially through the heads on the exhaust side.

From that picture, I would say that you could have had some localized erosion based on the significant clogging I see there, as well as the high amount of sediment. What kind of water were you running in? Regular old clear salt water? Sand filled salt water near a beach? That is a significant amount of deposition there, and I'm wondering if possibly a low flow/high temp condition initially started the sedimentation, and then lead to more and more deposits, and that problem created a positive feedback loop that lead to the eventual failure of the wall and gasket.

 

[WREKS]

NO worries. YOu did reply to my post, just called me someone else I knew what you meant.

I'm curious about the dead head space though. You don't typically see water jackets without at least decent flow paths, especially through the heads on the exhaust side.

From that picture, I would say that you could have had some localized erosion based on the significant clogging I see there, as well as the high amount of sediment. What kind of water were you running in? Regular old clear salt water? Sand filled salt water near a beach? That is a significant amount of deposition there, and I'm wondering if possibly a low flow/high temp condition initially started the sedimentation, and then lead to more and more deposits, and that problem created a positive feedback loop that lead to the eventual failure of the wall and gasket.

It doesn't take much to suck up some sand. And if the head gasket blocks circulation, flushing may not do the trick.

 

[Scottintexas]

@WREKS I'm sorry but I may have missed previous posts, you currently have the engine out of your boat ??
if so We needed a new thread on that, I probably skipped over this topic a number of times thinking it was just about tow valves,

Did you see crankygypys closed loop flush in the FAQ ??

not that that would help if you've got a corrosion hole in the wall,

.

 

[RICH_SX210]

I have my tow valves (I prefer to call them bypass valves as I never want to need to be towed) installed under the clean out cover accessed through the ports.
I close the valves for every flush whether on the trailer or in the salt water. By doing so you will get water out your pissers as it forces more water/Salt Away into the upper cooling passages of the engine. If you're sitting in salt water while flushing your pumps aren't going to be getting a flush anyway. I have no problem reaching my valves from my access ports.

@Gym, can you tell me what brand tow valve you used? I'm new to boating and I have a 2008 Yamaha SX210. I want to flush the engines while it's in the water and I'm trying to find a good valve for that.

 

[David Martin]

Water pressure will not broch a head gasket from the hose or pressure running under load............The head gasket is designed to handle vary high cyl pressures......way above what the water jacket pressures are on a gasket. Now if you look your breach was on the head side and it under cut your head gasket.....this is typical of the corrosion process.

Now your block and head is vary vary clogged and at some point the lack of cooling water will rise the pressure(water side) but this is not due to a Bypass valve or Hose over pressure. The hotter you get water the more it expands and your clogged engine also limits the volume which makes the pressure worse. At some point you could even steam the water....... steam pressures could get extremely high. A clogged engine along with poor water flow could cause the pressures to go vary high and breach gaskets and surfaces that are all ready weak from corrosion.

I think the big question we should ask is how in the heck did you not have overheat alarms ...........like a month to a year ago.......this IS ALSO WHY I NEVER TRUST a alarm system weather its a beeper or yellow light to tell me my engine is over heating A REAL TEMP GAGUE would have reviled temperature increases over a long time period/ like a year or 2 ago long before the alarm went off or the damage occurred .

Sorry I'll get off my rant about the lack of temp and oil gauges the brilliant designers thought we did not need.

 

[Julian]

Sorry I'll get off my rant about the lack of temp and oil gauges the brilliant designers thought we did not need.

I'm sure the designers wanted to put in oil and temp gauges, but the product managers vetoed them due to costs! Same for fume detectors & high water alarms.

 

[iflyrc]

I'm still trying to understand flushing while in the water. Although it makes sense this can only be accomplished with a tow-valve installed, upon completion of a flush in water, doesn't water still enter the pump from under the boat? What parts of the system are really being flushed?

 

[Scottintexas]

I'm still trying to understand flushing while in the water. Although it makes sense this can only be accomplished with a tow-valve installed, upon completion of a flush in water, doesn't water still enter the pump from under the boat? What parts of the system are really being flushed?

As long as you don't turn you engines on the only water that would get in would be gravity driven and I wouldn't think it would be able to make it up to the Y fitting and not into the engine itself, in the back it might go through the baffle but stop at the water box,

to me the main reason for flushing is clearing the water passages in the block/head/exhaust manifold I really don't believe water could get to those places without pressure pushing it,

 

[Beachbummer]

Entire Engine is being flushed. Valve is blocking pump/sea water from entering the engine while closed.

 

[Beachbummer]

Also, the engine has openings for the cooling water to flow out, even very high incoming pressure is divided into several paths that have several ways out of the engine once the cooling mission is complete. I suspect you would need to feed water at thousands of PSI to break something via water pressure build up, and you would probably blow the inbound hose before you broke anything else in the engine if you were trying... just a wild thought.

 

[BrentEB]

I'm still trying to understand flushing while in the water. Although it makes sense this can only be accomplished with a tow-valve installed, upon completion of a flush in water, doesn't water still enter the pump from under the boat? What parts of the system are really being flushed?

With the engines at idle "on the water" the cooling water pressure will be fairly low. If the water pressure from the hose is greater than the pressure from the drive pump, which is probably the case, water from the hose will flush the engine. You can check for the sound of water flowing through the hose or an increase in flow from the "pee holes" when the hose is turned on for confirmation of flow. Just turn the engine off and immediately turn off the hose at the end of the flush.

 

[Frank Marshall]

I'm still trying to understand flushing while in the water. Although it makes sense this can only be accomplished with a tow-valve installed, upon completion of a flush in water, doesn't water still enter the pump from under the boat? What parts of the system are really being flushed?

I installed shutoff valves with water filters. I open the water filters, film them with Salt Away and run the engines until I see foam at the back of the boat. That leaves Salt Away in the engine cooling system. Take at look at this thread: Shutoff / Flush Valve Install