Cracked block by oil jets?

[turbohounds]

I went to pick up my short block today, and on reassembly the machine shop found a crack out from the cylinder wall to the water jacket in all four cylinders. I've never heard of this in a 4g63. I've driven the car hard, but it never was overheated, or leaked any coolant into the oil or vice versa. Has anyone heard of this? Is it something common to check on a 4g63?

Thankfully the machine shop is finding a new block to make up for missing the finish deadline by a month. We definitely weren't expecting to find this since the car was running great until the timing belt broke.

 

[bullettdsm]

I went to pick up my short block today, and on reassembly the machine shop found a crack out from the cylinder wall to the water jacket in all four cylinders. I've never heard of this in a 4g63. I've driven the car hard, but it never was overheated, or leaked any coolant into the oil or vice versa. Has anyone heard of this? Is it something common to check on a 4g63?

Thankfully the machine shop is finding a new block to make up for missing the finish deadline by a month. We definitely weren't expecting to find this since the car was running great until the timing belt broke.

I'll jump in here for a what it is worth position. Checking for block cracks is common in any engine on a rebuild. That being said, I have seen my share of 4 cyl. engines and have yet to see one with ALL four cylinders cracked. You may have 1 or 2 cracks, and by that time you are looking for what is making your engine "run funny". Now, is it possible that you did do a oil starvation of some sort without knowing it? Maybe the oil pump did not shit the bed but did lose pressure. And yeah, maybe there was a blockage in a channel somewhere. How about doing some extended hard cornering? You didn't by any chance break what is MY number one rule for 4cyl engines and run it low on oil at any time?
That's the oil side of the picture, what about the coolant side? Basically same questions but exclude cornering and include thermostat.

But yeah, I too find that unusual. But stranger thing have happened.
MB

 

[turbohounds]

That's the thing, this engine was meticulously maintained - never more than half quart low on oil (always Mobil 1), and I have no evidence that the oil pressure was ever low. I had run a 13.2 on this block a few weeks before, so it was running great. It does have a FMIC and fluidyne rad, I never saw the coolant temp more than a touch above straight up on the interstate. I have been autocrossing the car since I bought it (so plenty of hard cornering). Machinist didn't find any blockages. I'm guessing then I just got a 'bad' casting. Better to know now before my stroker setup goes in, I'm half glad there aren't lots of responses so it shouldn't be hard to track down a good 6 bolt. I'll see if I can still get the block back from the machinist and shoot some pics of where the cracks are located.