ronniejoe - question regarding cracked blocks

[markrinker]

With your data, can you correlate frequency of cracking by region - i.e. is the cracking related to those of us that operate in cold climates or warm climates?

My theory, and rationale for using the block heater throughout winter, is that they start as a product of rapid thermal expansion as a sub-zero block of iron heats rapidly from the top of the cylinders after cold starting.

Just a theory. One other telling tale might be the month of the year that blocks are failing. Winter, spring, summer, fall???

Mark

[jspringator]

You may be on to something. I have noticed a WHOLE lot of new cracked blocks this month, but that could just be due to RJ's experiences, and other folks chiming in. I think I will plug mine in tonight!

[rjschoolcraft]

I didn't ask enough questions to be able to determine that information. Maybe a follow-up poll?

I posted the results in a .pdf file for those of you who do not have a cracked block and cannot view the results without voting.

[jdmetcalf57]

From and engineering standpoint and looking at my cracked block. These cracks are a fatigue problem. They take many millions of load cycles before they start and many more to develope long enough to cause a problem. Otherwise they take a lot of time.

In retrospect I think mine probably started leaking a very minor amount a year before it developed big enough to be a real problem.

[joe hatfield]

my 93 lost its first motor to a cracked block at 140K #8 hole. the 2nd motor (a new gm 6.5) lasted about 70K
has a crack in the lower head bolt hole on #8 crack runs from the cylinder wall to the bolt hole and out the side then down the block. its a beauty. anyone out there with a good bare block give me a call