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Cylinder blockface repair - another JBweld question

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  • Cylinder blockface repair - another JBweld question

    Reading the JBweld thread led me to thinking about a job I have on at the moment. 6-cyl diesel, one-piece head. It blew head gasket 4 years ago. I had the head skimmed, cleaned up the top of the block but it's not good. Fitted head with new joint + some high-temp jointing (Loctite product IIRC, can't remember which). Told the owner not to expect miracles, he was planning to sell the boat while the going was good.
    4 years down the line, he still has it & it's blown the gasket again between two cylinders. Block really needs refacing, but that's quite a big engine-out job, not practical at present and may cost more than the boat is worth.

    So.....is there any magic metal compound which could be used on the block face to build it up, which has a good chance of extending the life?

    I have Belzona 1111 to hand, but I wouldn't expect any of these epoxy-based compounds to last very long where they're in contact with the combustion space, even if it's only a very thin 'edge' which is in contact initially. Maybe I'm being too pessimistic?

    Thanks

    Tim

  • #2
    Maybe something like this,

    http://www.alvinproducts.com/Products/Products.asp?ID=2

    That and a solid copper head gasket? Or an aluminum one?
    Gene

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    • #3
      If it's a small groove between cylinders you could fill it with a stitching pin or several, peen and file it smooth. Lock n stitch is one brand. If you don't want to buy stitching pins you could use small screws instead. Assuming this block is automotive type design you only need a decent surface at the gasket fire ring, fill the rest with something easy like RTV or your favorite magic sealant.

      Comment


      • #4
        Depending on the situation, I have had good luck in the past simply by using a thicker head gasket.
        "I am, and ever will be, a white-socks, pocket-protector, nerdy engineer -- born under the second law of thermodynamics, steeped in the steam tables, in love with free-body diagrams, transformed by Laplace, and propelled by compressible flow."

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        • #5
          Belzona is usually a pretty good product if that particular one is for a filler type of repair for heat......my buddy had good success doing a Jaguar 6 cyl engine but it was a gasser so the combustion pressures are lower.......sounds like theres an inherant problem with that design......if the original isn't cutting it may be hard to expect any miracle cure to but I would offer the hail Mary to the owner vs removing that block for decking......with no guarantees.

          The real hazard here may be coolant leaking back into the cylinder and crankcase if theres a passage near the leak as the engine cools every time it's used and emulsufication damaging the bearings.......maybe thats not the case?

          Maybe this time he'll sell it?
          Last edited by hardtail; 03-24-2011, 12:57 PM.
          Opportunity knocks once, temptation leans on the doorbell.....

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          • #6
            I had a Astre (Vega in Pontiac clothes) with a similiar problem, undercut head surface at top of the cylinder on the water jacket side, little surface for the gasket to seat on. The car was old and not worth putting much into.

            I made a light skim cut on the damaged area with a Dremel to get good metal, and used steel filled epoxy to build up a area approximating the missing metal. Used a file to get the surface flat.

            It held for the remainder of the time I had the car, about a year or so.

            Steve

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            • #7
              What about lead? Torch it in and file flat.
              Andy

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              • #8
                take the motor out, surface the block and do it right - if not you will be back here in a couple more weeks asking the same question.
                "the ocean is the ultimate solution"

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                • #9
                  Originally posted by hardtail
                  Belzona is usually a pretty good product if that particular one is for a filler type of repair for heat......my buddy had good success doing a Jaguar 6 cyl engine but it was a gasser so the combustion pressures are lower.......sounds like theres an inherant problem with that design......if the original isn't cutting it may be hard to expect any miracle cure to but I would offer the hail Mary to the owner vs removing that block for decking......with no guarantees.

                  The real hazard here may be coolant leaking back into the cylinder and crankcase if theres a passage near the leak as the engine cools every time it's used and emulsufication damaging the bearings.......maybe thats not the case?

                  Maybe this time he'll sell it?

                  No, it's blowing between cylinders, it's a fairly narrow land between them and of course a bit more of it gets eroded each time a gasket blows.

                  The new gasket is having to be specially made in solid copper, previously it's been old stock copper/as**stos but no more are to be found (it's a 1954 engine). That might give it more of a chance than the composite gasket.

                  No, as I've already said, taking the engine out and stripping it to do the job properly is NOT an option at this stage.

                  Thanks

                  Tim

                  Comment


                  • #10
                    iam not for any sort of epoxy soloution for this so you got 2 options, take out the motor and do it right or, use HTS-2000 that can also fix it properly

                    do not melt lead in its not going to hold for more then 20 min or so then youll be back where you started...

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                    • #11
                      It might be worthwhile contacting Belzona for their recommendations. The 1111 might be applicable, but temperature resistance is on the low side. It would depend to a degree on how thick the application is. The copper gasket might work to your advantage.

                      http://www.belzona-bsn.de/downloads/1111ps.pdf
                      Jim H.

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                      • #12
                        Originally posted by airsmith282
                        iam not for any sort of epoxy soloution for this so you got 2 options, take out the motor and do it right or, use HTS-2000 that can also fix it properly

                        do not melt lead in its not going to hold for more then 20 min or so then youll be back where you started...
                        Never heard of HTS2000 before, just googled it & it's an aluminium 'brazing' alloy. This is a cast iron block, are you suggesting it would work or just guessing it's an ali block?.

                        Tim

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                        • #13
                          If it's a fresh copper gasket great if not it will need to be annealed.......other have found success with giving an old gasket a light coat of aluminum rattle can spray, others yet aviation permatex.......but since the area has been under attack previously and now again I have a feeling the gasket is toast for sure.....if there is any chance combustion flame will touch the lead I think it would just melt out. Either way the gasket is just to seal 2 good mating surfaces and missing parent material will have to be replaced by something. The Jaguar repair was in a similar area as this engine.....this engine have seperate firerings or just the gasket?
                          Last edited by hardtail; 03-24-2011, 03:50 PM.
                          Opportunity knocks once, temptation leans on the doorbell.....

                          Comment


                          • #14
                            Seems to me that if the land between the cyl bore is narrow, the expansion & contraction from heating/cooling plus diesel hammering would fairly quickly cause any sort of epoxy/magic compound to crack loose and erode away.

                            Is Tig welding or brazing a possibility followed by a bit of dressing of the area with a die-grinder and a nice new flat file?

                            How many cylinders does it have? Can you jerk the 2 injectors from those cylinders and just say it's the all new for 2011 Green Edition that burns less fuel than the old 1954 model?
                            Milton

                            "Accuracy is the sum total of your compensating mistakes."

                            "The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton

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                            • #15
                              It's a bit out of the ordinary, but could you build up the area using a metal spraying technique? It might give enough build that a gasket is properly supported.

                              Michael

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