? Cracked B Block

V

verdirick

Senior Member
Just got a rebuilt B engine running in a stand and have found lower compression (70) PSI one cylinder # 3. Pulled the manifold and found rust in valve chamber below the valve chamber below the valve seat itself( No 5 exaust). No problem with the head. Machine shop to do pressure test on the block in the morning. Has anyone out there run into this problem? Afraid that I have a 2K invested in a boat anchor. Any ideas of how to repair if we find a crack. Appreciate any help.
Thanks
Rick Jensen
(775) 527-1419
verdirick1@gmail.com
 
There is probably any number of repairs that could be made. The pro's will reply soon enough & hopefully know a good repair method. Never throw away anything, new technology can fix things when it gets invented even you have to wait a little while for someone to think of it.
 
"B" engines are more likely to get cracks in the EX seat areas than "A" blocks, i have also seen the ports rust through, many of these cracks can be fixed, rusted through is a problem though, any welding should be done with the block heated to a high temp, to help with you education about cast iron crack repair ---even if you have no plans of trying yourself http://www.locknstitch.com/ I have and use some of their products and although they cost some $$ they work, and having tried welding in the past and have caused more problems in what I tried to repair
 
I would find a machinist familiar with lockN stitch products first to see if it can be done. Cracks in the valve port can be difficult to access and repair. If that machist cannot do it, Rick Gertseems is incredibly talented. He has done several very difficult welds to bad blocks. He did one of my B engines very well. http://www.accastingrebuilders.com/experience.html

However, welding will ruin your bearings if they are babbitt, and could require boring the cylinders and decking the block to clean up any warping from the heat. That's why I would try stitching it first.

call Lock N Stitch to find someone near you who is familiar with their installation
 
I fixed one in that area not too long ago by silver soldering.
You might have to do the valve seats in that area again but no big deal.
If it is as I picture it, you won't get any heat in the main bearing area to bother the babbit.
 
Pete< Can you repair FW housings with silver solder? I have one with the beginnings of a crack in it. I drilled small crack stop holes and I've been wondering about silver solder too. Preheat the whole thing and then heat the crack area with the torch. I have two housings I'd like to save if possible
Terry.




Pete said:
I fixed one in that area not too long ago by silver soldering.
You might have to do the valve seats in that area again but no big deal.
If it is as I picture it, you won't get any heat in the main bearing area to bother the babbit.
Click to expand...
 
Lock and stitch sounds good even though i have never seen it, only read about it on the internet. Silver solder might work if it is rusted through and chemiweld might take care of block leaks if you get any from the above mentioned surgeries. Should last 20 years anyway.
So i had this theory about repairing engine blocks with electroplating... but it turns out it is beyond my means. There will be a day when it will seem like a good idea when there are no more left to fix but if that guy casting 5 main bearing blocks is successful that day will be a long long time away.
 
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