Cooling ports too occluded to save?

[brownoarsman]

Due to bolts that were corroded to the head and block, I had to wedge and pry the head off my diesel. The engine is a universal 5411 that has been raw water cooled for the entirety of its 35 year life. The head had to come off because water was leaking into the cylinders and a failed head gasket seemed likely. Now that I'm in, it doesn't look too bad though except for the occluded cooling ports that you'll see above and below the cylinders and around the remaining studs. The first pic is the block, and you'll see the four cooling ports right above and below the space between the cylinders. The second picture is the head, and two of the head's cooling ports are still open. I've gently prodded the blockage with an ice pick and it feels fairly solid. I believe the gasket was leaking due to the rust stain visible between the two cylinders on the blocks.

So, can an old universal 5411 with
-occluded cooling ports in the block and head
-what looks like rust between the piston bores due to a leaky gasket (perhaps)

Be saved? Pics below, and thanks!







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[brownoarsman]

Here is a close-up of two of the ports next to the stud that's rusted in. They are to the right of the stud which is itself to the right of the cylinders.

There is junk in the cylinders, but I have not moved the pistons since the junk landed in there, so no scarring of the walls. Thanks!



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[sailorchic34]

What you want to do is put the head back on and connect some hoses to the cooling inlets and outlets to a pump in the bucket. Mix a quart of Muriatic Acid to 2 gallons of water and circulate the water through the engine for 15 minutes. gloves and goggles are a must.

Might have to do that a few times. You need to do this with the head on with a head gasket as the acid would cause the cylinder walls to rust if it got on them.

[Jim Cate]

Originally Posted by sailorchic34

What you want to do is put the head back on and connect some hoses to the cooling inlets and outlets to a pump in the bucket. Mix a quart of Muriatic Acid to 2 gallons of water and circulate the water through the engine for 15 minutes. gloves and goggles are a must.

Might have to do that a few times. You need to do this with the head on with a head gasket as the acid would cause the cylinder walls to rust if it got on them.

Agreed with this general approach to de-scaling the cooling galleries, but I'd spend some time with punches, chisels and other instruments of destruction, removing as much of the scale mechanically as possible. This will speed up the chemical dissolution process significantly, and it is soul-satisfying to beat the crap out of things with a hammer!

If I understand your post correctly, there are some broken off studs to deal with too. I think I'd get them out first... it's gotta happen sometime, and if it is a no go, you will have saved a lot of effort in the descaling!

Hope you are successful, and at a reasonable cost.

Jim

[brownoarsman]

Thanks for the advice! Those head gaskets are about $150 a piece (even from the tractor dealer), so would it work to keep the glow plugs/injectors out so that the pistons aren't developing pressure, RTV a gasket in there instead, and just use the starter motor and the water pump, in bursts, to push the acidic water through? The wet exhaust manifold has also failed, but I started another thread on that ages ago that had some good ideas

Also, some various pieces of metal gasket and other sundry debris definitely got into the engine internals through the oil openings, is the best thing to do to drop the oil pan and flush the internals with oil through the openings in order to clear it all out?

I particularly like the idea of going to work with punches after the satisfying experience of finally getting the head off following months of soaking the block/head seam with PB blaster and pouring it into the sheared bolt holes to no avail. Unfortunately I was a bit overzealous and scarred the head a bit. But I guess that's what machine shops are for?

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[Lepke]

A product I use is Archoil AR5100. It is an industrial rust remover that does not harm people or the environment. It can be pumped thru the engine or used for soaking. It removes all the rust down to good metal without damaging the good metal. The finished steel I have done looks like is was fine sand blasted with no apparent rust. It mixes 16 water to 1 AR 5100, but can be used stronger. I have only used it 16:1 and it worked fine on overnight soak.
For unsoakable parts, I saturate cotton caulking and place in contact. It also will remove corrosion on brass, aluminum, etc., w/o damage. Solution can be used until neutralized. Doesn't harm rubber, plastic, fiberglass, fingers, etc.
Remove easy excess rust 1st to get more mileage out of the remover.
Available online.

I would buy a heat exchanger and a 2nd pump. Raw water cooling is probably why you have this problem.

[Winf]

Will add my 2cents worth here and I don't speak from experience, only from what I read somewhere and was told by a experienced fisherman.

If you get it all cleaned up and going again, check your thermostat operation. My Yanmar 3HM30 is raw water cooled. I read/heard that it was important to make sure that the thermostats were in place and that they were opening at the correct temperature.

Something to do with solids precipitating out of the seawater if it's temperature gets too high and this then blocking the cooling passages over time.

Winf

[bsurvey]

send the head out have it boiled and magna fluxed. it could be too corroded to waste your time with the rest of it


any machine shop can do this

[bsurvey]

the head could be warped from high heat and the blown head gasket. at which pint if it can't be reconditioned what is the point in going further with this engine

[bobnlesley]

Originally Posted by sailorchic34

...in the bucket. Mix a quart of Muriatic Acid to 2 gallons of water and circulate the water through the engine for 15 minutes. gloves and goggles are a must...

Woulr this process work on a small outboard engine? We have a small 2-stroke outboard in which I suspect the cooling galleries and waterways are somewhat restricted by corrosion/salts-build-up. Beyond perhaps needing to repaint the leg, what harm would I do by standing said outboard in the muriatic/water bucket and letting it run for 15 minutes?

[liveaboard60]

Originally Posted by bobnlesley

Woulr this process work on a small outboard engine? <snip>

Good question.. I too have a small little outboard I would like to flush, so I too would like to know if the muriatic acid solution would help clear any buildup.. flk k

[Jim Cate]

Re Muriatic acid (HCl) and outboards: Don't do this! Outboards are usually largely aluminium construction, not cast iron like most (all?) marine diesels, and the HCl will attack the aluminium vigorously.

There are non-acidic descaling products that may be useful... I can't comment with any knowledge, but some research should be informative.

Jim

[sailorchic34]

What Jim said. Don't use acid on aluminum.

Better to use aluminum radiator flush, available at auto parts. Its generally caustic potash.

[Jim Cate]

Originally Posted by sailorchic34

What Jim said. Don't use acid on aluminum.

Better to use aluminum radiator flush, available at auto parts. Its generally caustic potash.

Interesting idea, SC. Is that effective on salt buildup (or whatever that cement-like crap that builds up in the coolant galleries is)? I'm not enough of a chemist to know what eats what in the real world!

Jim

[sailorchic34]

Well it's mainly calcium and other minerial buildup. Mind you in an automobile it's a much slower buildup. Odds are it will take some time on an outboard. But it is save for Aluminum while acid is not.