Cylinder block corrosion

[BarryT]

I am looking for ideas for repairing the cylinder block on an old Volvo engine

Having just blown a head gasket and discovered a small corrosion channel between the cylinder and one of the raw water cooling tubes I seem to be faced with the choice of engine replacement or an expensive weld and skim to the cylinder block.

However a couple of months ago there was an article in PBO describing sinking bolts into the block across the corrosion line and filing them flat. Is this just a short term repair doomed to failure ? What about compatibility of material ? It seems to go against the grain to drill extra holes in the block !

Alternatively, it seems amazing that in this modern age there is no high performing sealant/filler that can be used. Various compounds seem to claim to be harder than steel, but how would they cope with the high pressures in a diesel engine ? Has anyone used any such compounds ?


Any suggestions ?


Barry

 

[dickh]

There is a commercial system called "METAL-LOK" or something like that, it uses a similar method of drilling holes and then inserting a shaped insert. Mainly used to repair cracked or broken large castings. Never had to use them so I don't know if it would work in your instance.
Alternatively you could try a material called "DEVCON" which is used for repairs in steel and Cast Iron.

 

[kgi]

im with DickH Devcon is good stuff make sure you get the right grade, they use it in racing motorbikes for altering the shape of the exhaust ports and for altering crankcase compression as well cheers keith

 

[chas]

Recently I was looking for some sealant on the web and I came accross a site called www.fastenal.com which had a metal filler that claimed to be strong enough to be used for repairing blocks. I cant remember what it was called as it was not quite what I was looking for at the time!

Hope this helps

 

[vyv_cox]

I thought the repair shown in PBO was quite clever but it does require some good engineering skills. Drilling and tapping half way across fitted stud bolts is not an easy thing to do. If your burnt channel is not very wide you might get away with just one stud width, which would not be too difficult to do. I would be careful about making the stud too large, anything over about 6 mm might lead to other problems. There are no compatibility issues between steel studs and a cast iron block.

Metalock is a good process and we have done some serious repairs using this method. I have never seen it done on such a small area, though.

I doubt that you will have much success using plastic type fillers because of the combustion in the cylinder. There will be a progressive burning of the filler over time unless the burnt channel is very shallow. If I was going this way I would try Belzona (www.belzona.com) Not cheap but we have used it to carry out a wide range of repairs in industrial machinery.

One last one. A complete bodge but it worked. I once had a similar problem and rolled up a small piece of thick aluminium foil, put it in the eroded channel and replaced the head and gasket. It worked for a long time.

 

[Guest]

Re: JB Weld?

I have used JB weld for metal repairs, but do not know if it would suit your application. Worth a check. It is easily obtainable.
Like the sound of Devcon, but no knowledge.

 

[BarryT]

Thanks for the suggestions, I'll let you know how it all goes.


Barry

 

[ParaHandy]

Presume you mean plastic fillers such as Devcon? Agree 100%. I think there's a thermoset compound in it which makes it an easily workable paste but which will self destruct at diesel temperatures.

 

[AndrewB]

Epoxy filler

I have doubts too. I think Devcon is very similar to Plastic Padding "Super Steel" Epoxy and Bondo Epoxsteel. Product sheets for the latter recommend against high temperature applications.

 

[numenius]

Over the years and seen others (and tried myself) try all sorts of repairs to blocks on diesels - from tractors to boat engines. From "miracle" plastics to brazing, to making special plates and drilling and tapping bolts in etc (and poured in many pounds of block sealant)...Unless something has come on the market in the last couple of years (and almost every year someone comes up with a new "wonder cure") , then unfortunatly EVERY method I've seen has on lasted temporarily. Whilst we've certainly managed to gain a year or two out of the odd Landrover or other engine, I certainly wouldnt rely on one if my boat engine need it - personally, it would be a new block. Not what you want to hear I know.

http://members.lycos.co.uk/boaty1965/index.htm