Y block visual crack ID

V8 Bob

V8 Bob

Well-known member
I'm dismantling several 292 Y blocks, and have found small amounts of water in the oil pans, but can find no obvious pan rail or block cracks in any of them. My question: Are there common areas I've missed that would show freeze cracks in these engines? I would like to sort out the bad blocks before getting them professionally cleaned and crack checked at the machine shop. Thanks.
Bob
 
If they have been on a concrete floor, it may be condensation. The only Y block I ever saw cracked was down the outside from top to bottom in front of the oil filter. It was in a truck. The owner cleaned it with carb cleaner, and fiberglassed the crack. He ran it for years with the radiator cap loose. Look in the crankcase area near the bores, and the lifter area.
 
Not a common problem, I have done a few of these and never had a cracked one yet, I have bored 292 out to 309 cube no problem and never had any issues. They are a fairly stout block. Core shift is more of a reported problem not that I have seen it personally.
 
I have a 292 block that had cracks down the front on both sides behind the timing cover where it had frozen. Someone reapaired it by running a continuous bead of brazing at the cracks. I ran the engine for twelve years and it never leaked water in the oil or on outside.
If you take the block to a hot tank for cleaning, they can detect cracks with magnaflux.
 
I have seen and had cracked heads on the Y blocks. The cracks were always adjacent to a head bolt, or multiple head bolts. The solution and way to avoid this problem is to use the very thick Chevy big block head bolt washers under the Ford bolts.
I had one set of Y block heads on my Bird 312... The heads had been completely rebuild as had the engine. Shortly after getting the car running I started to note condensation in the oil breather cap, this was in spite of the '64 truck PCV sustem I had on the engine.
We pressure and dye checked everything on the engine... no leaks. Many people posed the thought that the PCV was the culprit.. Nada.... After several weeks of running the car I decided to check the valve lash, which requires the engine to be running.
After the engine was properly warmed up and the valve covers removed, low and behold very small coolant drops were observed coming from minute cracks around the head bolts.. Of course everyone involved with the rebuilding of the heads denied any responsibility. A good friend of mine suggested the CBB head bolt washers.... Problem solved. If you think about it, torquing head bolts directly to the head could be very harmful to the metal surrounding the bolt heads.
 
Dave and Bill, thanks for the info and tips.
The head bolt washer idea is a good one, something routinely done with aluminum heads. :)
 
You must log in or register to reply here.
Back
Top