gonna try running cracked block
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gonna try running cracked block This is an LQ4 block. The crack has been marked with white-out. It's just a tiny pin-hole, so I'm going to go ahead with a mild build, and see what it will survive.
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And here's a pic of how I found the crack. It didn't sound all that different from the others. I walked away, drank a Pepsi, then came back and repeated to make sure.
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This wasn't the best test procedure, my air tool leaked, so the real leak was hard to hear. But it was the only one to lose pressure in 2 seconds, the others all took 3. I could feel the air escaping when I got a finger there. I repeated the finger test as well, on every other one.
Then I had a better idea. I'd put water in the jackets, and watch for bubbles. None of them did that, so I'm convinced I've found my only problem.
The next step will be me taking it to the machine shop.
Then I had a better idea. I'd put water in the jackets, and watch for bubbles. None of them did that, so I'm convinced I've found my only problem.
The next step will be me taking it to the machine shop.
Why? These blocks are cheap as hell. Do you live in an area where they are hard to come by? Do you have X amount of money tied up in the block? Do you want an excuse to rebuild it in a short time? Do you LOVE carnage?
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To answer your only relevant question, yes, I do live in an area where these are hard to obtain at any price. Even in Salt Lake City, which is 100 miles south, they're still challenging to get for less than a grand.
I don't understand how we got to the point where 99% of enthusiasts mistakenly believe that any crack renders a block junk. I've successfully run bigger cracks than this, but they were in the traditional SBCs and BBCs. This is my first cracked LSx. I'm curious to see if it'll do what all those stock Ford 5.0 blocks do when you push them past 650 rwhp. They literally split in half.
I'm not putting this in my daily driver, it's going in my weekend toy. So if it does let go at a bad time, well, I won't miss work, I can wait for AAA to send a tow truck.
Are you really not even a little curious to find out what it'll survive?
I don't understand how we got to the point where 99% of enthusiasts mistakenly believe that any crack renders a block junk. I've successfully run bigger cracks than this, but they were in the traditional SBCs and BBCs. This is my first cracked LSx. I'm curious to see if it'll do what all those stock Ford 5.0 blocks do when you push them past 650 rwhp. They literally split in half.
I'm not putting this in my daily driver, it's going in my weekend toy. So if it does let go at a bad time, well, I won't miss work, I can wait for AAA to send a tow truck.
Are you really not even a little curious to find out what it'll survive?
To answer your only relevant question, yes, I do live in an area where these are hard to obtain at any price. Even in Salt Lake City, which is 100 miles south, they're still challenging to get for less than a grand.
I don't understand how we got to the point where 99% of enthusiasts mistakenly believe that any crack renders a block junk. I've successfully run bigger cracks than this, but they were in the traditional SBCs and BBCs. This is my first cracked LSx. I'm curious to see if it'll do what all those stock Ford 5.0 blocks do when you push them past 650 rwhp. They literally split in half.
I'm not putting this in my daily driver, it's going in my weekend toy. So if it does let go at a bad time, well, I won't miss work, I can wait for AAA to send a tow truck.
Are you really not even a little curious to find out what it'll survive?
I don't understand how we got to the point where 99% of enthusiasts mistakenly believe that any crack renders a block junk. I've successfully run bigger cracks than this, but they were in the traditional SBCs and BBCs. This is my first cracked LSx. I'm curious to see if it'll do what all those stock Ford 5.0 blocks do when you push them past 650 rwhp. They literally split in half.
I'm not putting this in my daily driver, it's going in my weekend toy. So if it does let go at a bad time, well, I won't miss work, I can wait for AAA to send a tow truck.
Are you really not even a little curious to find out what it'll survive?
You don't understand how people that throw hundreds if not thousands of dollars at engines running on tight clearances, high stresses, and borderline part failure don't want a perfect block to start with?
Sure, I am very interested, but I wouldn't want to find out with my money tied up into the block, and it's not, it's yours, but from your prospective, why?
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Apologies, no disrespect intended.
Having been impressed by my LM7, I do want to sample an LQ, and I do want to know if I should be grabbing up other people's discarded blocks, for free.
Who else would try this, then share the results?
I'm not buying pistons, rods, crank, or any of those other expenses. Putting a new aftermarket crank in this block seems unwise, in case the crack does grow.
And if this was an LM7 or LR4 block, I wouldn't build it.
Having been impressed by my LM7, I do want to sample an LQ, and I do want to know if I should be grabbing up other people's discarded blocks, for free.
Who else would try this, then share the results?
I'm not buying pistons, rods, crank, or any of those other expenses. Putting a new aftermarket crank in this block seems unwise, in case the crack does grow.
And if this was an LM7 or LR4 block, I wouldn't build it.
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cdd as long as the head bolt will torque down i be it it gives no problems i had a outter bolt hole crack, i dont know how long it was there but when i found it had it welded this was a h/c/i/nitrous 347 almuminum block never had a problem
Does the crack carry on to the cylinder wall or no? That's still pretty close to the cylinder. I'm sure all it needs is time until the block comes apart and the weakest part is indeed that crack...
excited to hear of your results, I have wondered the same thing about bad blocks 
I wouldn't use it. But if I had no choice, I would de burr the pin hole and apply some epoxy to it. It acts just like a crack in a windshield. It can start very small, and from heat and vibration it can carry all the way across the windshield. But if you drill pin holes on each end of the crack it will not grow anymore.
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This is quite a lot more controversy than I expected. I thought everyone would tell me to forget it, which I will not do. There's some great input, which I appreciate.
My plan, which has not changed thus far, is to drill one hole, larger than the crack, which literally is a pin hole. That means a 1/16" drill bit will be large enough. Then I'll do what's always worked best on other cracked iron Chevy blocks I've run successfully: J.B. Weld.
That 350 I saved 9 years ago is still being driven every day. It had a 5"-long crack in the lifter valley, going through to the water jacket. I used a little Moroso block filler on the inside, in the jacket, with the block clean and tilted over on a stand. In the lifter valley, I used the J.B., but didn't drill the ends of the crack. About 16 months ago I changed intake manifolds, and everything still looked exactly as when I fixed it.
I have other examples, including a freeze-cracked 454 which I still have, but I don't want to get too far off topic. I just want to make the point that I have experience with getting good service from cracked iron Chevy blocks.
It'll be spring before I first start this engine, and I will start a new thread at that time.
My plan, which has not changed thus far, is to drill one hole, larger than the crack, which literally is a pin hole. That means a 1/16" drill bit will be large enough. Then I'll do what's always worked best on other cracked iron Chevy blocks I've run successfully: J.B. Weld.
That 350 I saved 9 years ago is still being driven every day. It had a 5"-long crack in the lifter valley, going through to the water jacket. I used a little Moroso block filler on the inside, in the jacket, with the block clean and tilted over on a stand. In the lifter valley, I used the J.B., but didn't drill the ends of the crack. About 16 months ago I changed intake manifolds, and everything still looked exactly as when I fixed it.
I have other examples, including a freeze-cracked 454 which I still have, but I don't want to get too far off topic. I just want to make the point that I have experience with getting good service from cracked iron Chevy blocks.
It'll be spring before I first start this engine, and I will start a new thread at that time.