Block cracks

Chuck Sea/Tac

Chuck Sea/Tac

Well-known member
Other than the top of the block, where are the common cracks found, when checking a block for rebuilding. I am using a block tester at 40#s.
 
40# sure sounds high, especially for an unpressurized system. I bought a block at an auction 20 years ago, but when I got it home I found a crack in the valve chamber, near the center.
 

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Are you saying 40# of air pressure in a bare block on the stand and using good soap / bubble mix in a spray bottle. If there is a crack that leaks, you'll find it.
 
Yes, that's what the instructions say for pressurizing a bare block. It works great. So far I e tested 4 different blocks overnite and they all held. In fact the only leaks I've found were in the nipple to gauge connections.
 

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Chuck,

Look at the water jacket areas at the front and Inlet side of the block. Attached is a photo of a front repair l made on a freeze crack on a Model B engine more than thirty years ago.

At the time l used 1/8" solid brass pipe plugs, since that time Pete has changed my thinking to the use of solid Cast Iron pipe plugs.

Hope this helps.

Darryl in a beautiful Fairbanks
 

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100IH said:
Are you saying 40# of air pressure in a bare block on the stand and using good soap / bubble mix in a spray bottle. If there is a crack that leaks, you'll find it.
Click to expand...


Many a crack are old ones, and don't leak, because of rust and old crack sealer. Block should be free of all rust, just to find a crack that will not leak under pressure testing.

After a block is boiled out, the block should be made sure that it is dry, as water in a crack will not show up a crack with a dry magnaflux.


Herm.
 
your block can be welded if you take it to the right person that knows what they are doing. We have welded high performance engines and they hold to gether.
 
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