Re: Cracked Block. How long will it last, what to do? Pics Included.
That's not the block that is cracked. It is the matching plate. It mates the block to the midleg and delivers cooling water to the block. It also holds the exhaust downtube and (in the front) part of the shift linkage. It looks like the pry tab has broken and the resulting crack is leaking water.
The match plate has several circuits for draining USED cooling water into the midleg around the exhaust downtube. This is one of them. The leak will do no harm since that water has already been used to cool the block and head. There is a gasket between the match plate and block, but no gasket at this junction ( match plate to midleg) and most I have seen were sealed with a little silicone RTV.
You can leave it alone, OR, what I would do--- Schmutz a little epoxy into the crack to seal it. Dont push it too far in and block the passage though. There is very little pressure and heat there so you don't need to worry about the epoxy being forced out. Just be sure to clean the area with solvent to get rid of any oil that may be there, dry it well, and rough up the outer surface so the epoxy gets something to grip onto. Eventually, if you should ever need to rebuild the engine, buy a used plate off a junker.
Judging by the condition of the bolts I can see, the engine has been rebuilt at some time; that's why the tab is broken. sometimes the six studs holding the block to the midleg corrode in and it can be very difficult to separate the block and match plate from the midleg.
