MD11d cylinder head cooling circuit problem

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Timisco

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Hi guys,
I'm new in the forum,
I posted in an old threads non directly related to my problem so I open this.
I'm the owner of a Pretorien 35 with a Volvo MD11d.
I'm trying to reassemble it after raw water cooling problems.
I have to figure out if my cylinder heads are ok, I have 2 pairs of them but they have the same problem, there is a hole on the wall between the inlet and the outlet of the coolant (raw water).
A mechanic suggest that is normal...
I attach a photo. It is supposed to be?
I hope someone knows the piece...
Thanks a lot
Claudio
 

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Unlikely that VP intended it to be like that; as new cyl heads are not available wobbing it up with epoxy is the least worst but ultimately short term fix. A new engine beckons.
 
The inlet to that cylinder and head is the wee round port and that goes to the head joint area and on to the lower lower block area passing down a drilled passage in the block. the water having done its job around the liner passes back up into the head space. before passing back to the manifold. I only have older heads here and on them there is no large port above the wee drilled port so I can t help further but suspect it is possible that the system will still behave ok as it is as that water in the head is all heading for the manifold.
 
Thank you guys.
I had a reply from a guy saying he had the same regular hole in his cylinder heads.
I'm planning to assembly everything back in 2 weeks, crossing fingers.
Now the only concern is that Bilgediver doesn't have the same configuration in his cylinder heads.
Hope is the last chance...
 
Timisco said:
Thank you guys.
I had a reply from a guy saying he had the same regular hole in his cylinder heads.
I'm planning to assembly everything back in 2 weeks, crossing fingers.
Now the only concern is that Bilgediver doesn't have the same configuration in his cylinder heads.
Hope is the last chance...
Click to expand...
Mine are the older design as on MD2b basically the same design and circulation flow.however on those all the water is directed out by that side port and the centre one does not exist though there is a hole in the gasket.
As a matter of interest. Does your manifold have a port in it for that central hole or is it blanked off?
 
Timisco said:
It's blanked off.View attachment 111112
Click to expand...

That is what I suspected. In that case you probably will be OK leaving it alone . One thing you should check while it is all apart is that the cooling inlet ports are all clear from that round hole in the manifold flange area into the head and then out at the head gasket face and then the corresponding hole from the head gasket face down into the bottom of the block. also check that the drain cock ports in the block are clear. The cock screw in inserts can be screwed right out to give a clear passage.
 
Bilgediver said:
The inlet to that cylinder and head is the wee round port and that goes to the head joint area and on to the lower lower block area passing down a drilled passage in the block. the water having done its job around the liner passes back up into the head space. before passing back to the manifold. I only have older heads here and on them there is no large port above the wee drilled port so I can t help further but suspect it is possible that the system will still behave ok as it is as that water in the head is all heading for the manifold.
Click to expand...
That must just be there for maintaining consistent wall thickness for casting; I unreservedly withdraw my suggestion of wobbing epoxy into the hole as it's doing nothing, the cause of any cooling issue lies elsewhere. What specifically was the cooling water problem OP?
 
penfold said:
That must just be there for maintaining consistent wall thickness for casting; I unreservedly withdraw my suggestion of wobbing epoxy into the hole as it's doing nothing, the cause of any cooling issue lies elsewhere. What specifically was the cooling water problem OP?
Click to expand...


I suspect the problem is the cooling passage in through the small round hold down to the bottom of the block past the head gasket to a gallery around the base of the liner. There is a tendency for folk to ignore these wee holes. also mud and rust particles fall to the bottom of the lower gallery and this restricts circulation. The lower gallery can be cleaned by prodding or water pressure through the drain cock hole. Also clear the four vertical drilled ports around the liner which carry the water back to the head by proddind with a steel rod or even long screw driver. The lower gallery can also be cleaned by removing the cylinder liners and when replacing them put them back with new seals in a different position. The reason for this is that during the life of the engine the Gremlins in the engine are neatly drilling a hole through the liner opposite the drain cock. Eventually the first thing you know is water in the oil. Difficult to identify source as this hole is always covered by the piston. Catch it soon enough and rotate the liner then it lasts longer.
There was an article in PBO some years ago about overhauling one of these engines with liners . In one of the pictures the hole was clearly visible but no reference made to it in the article????????
 
Scale build-up won't help, although pickling to remove it is like russian roulette in a raw-water cooled engine that old; mechanical removal as you outline is the low risk option.
 
Thanks you for the replies, I had a problem of overheating and than a water leak. It was full of rust not just scale for this reason I thought about a hole made by rust. I cleaned all the pipes in the cilynders, heads and manifold.
I don't want to touch the drain cock, cause the rust I'm worried, no one touched it for 40 years if it is brake itself... I'm done.
 
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