Engine Build- UH OH!

After writing my last post I ran into a MAJOR problem, by major I mean one of the worst things that could of happen other than blowing the thing up, at least that's what I initially thought.  After the initial break in I ran it a couple more times and each time I kept noticing a small coolant drip on the floor.  I took a couple bolts off the block and sealed them thinking that this was the source but it never stopped.  Well after awhile I seen where the drip was coming from, BEHIND the engine block paint!  I grabbed a screwdriver and chipped away the paint and there it was a crack in the water jacket on the block.


Small crack can be seen after I chipped the paint away. 

After I was done swearing, and throwing things around the garage I calmed down and thought about my options.  Option 1, scrap the block and get a new one.  New was going to be around $2000, another used block was going to be around $1200 by the time I had it re-machined.  This option would require me to completely disassemble the engine and start from scratch.   Option 2,  I buy some of these "miracle" crack repairs that you put into the rad and circulate through the coolant.   Option 3, try and find a good enough welder to weld cast.  Option 4, a procedure called "cold metal stitching" where a series of threaded overlapping plugs are installed along the crack which fuses all new material where the crack was originally. 






luckily the machine shop that had done all my original machine work to the block said they could do the stitching for me.  I decided to go this route because I didn't want to start from scratch and I didn't want the "patch" job of using the rad/coolant fixes.    So I had to drain all the coolant and oil and take the carb off for them to do the work.  I then loaded it up and dropped it off at the shop.  After a couple weeks I picked it back up and it looked great.  The real test was going to be running it again.  They were confident.


This is the full crack that can be seen after magna-fluxing

It was a lot bigger than I expected it to be

Here is the finished job, if you look closely you can see the small plugs along the crack

I just need to repaint it now

Loaded up, on way home.

I took it home and hooked it all back up to my engine stand, and fired it up.  I put some Irontite All Weather Seal (shop recommended this as a insurance).  It is a sealant that is put in with the coolant that searches out and leaks any seals them up.  Well after running for a good 40 min or so of hard revving and idling,  I can report NO LEAKS.  Now I hope it holds up over time.




I learned one big lesson.  When using a used engine block for a build, have it checked for cracks.  I had painted the block before bringing it in to initially have it machined, I guess I shouldn't have done this because they can't magna-flux the block over the paint.  I didn't know this.  I also think that they should have suggested that I strip the paint off and have it done.  I think there were faults on both sides.  I know for next time now.  lesson learned.