Cracked Block... Possible Cause??
#1
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Car: '85 IROC
Engine: LB9
Transmission: 700 R4
Cracked Block... Possible Cause??
There's a crack in the cyl wall of a block that I've been working on. The crack is vertical, and about 3/4" long, and about 3" down the bore of a cyl.
I was able to measure the thickness of the cyl wall at the point where the crack is, because it's directly below one of the large holes in the deck. So I passed a caliper down inside there and took a measurement, and the wall thickness is normal, or about the same as any of the other blocks I have.
I'm wondering what could have caused that crack?
Also, I'm wondering if a treatment of Hard Blok could be a possible repair method if the crack were fully covered up by the filler?
Thanks
I was able to measure the thickness of the cyl wall at the point where the crack is, because it's directly below one of the large holes in the deck. So I passed a caliper down inside there and took a measurement, and the wall thickness is normal, or about the same as any of the other blocks I have.
I'm wondering what could have caused that crack?
Also, I'm wondering if a treatment of Hard Blok could be a possible repair method if the crack were fully covered up by the filler?
Thanks
#3
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Car: '85 IROC
Engine: LB9
Transmission: 700 R4
Don't know if it ever froze. I bought this block rebuilt about 15 yrs ago and I'm just now getting around to using it.
The warranty is long past expired or I'd take it back.
It could be sleeved, but I just thought I'd ask about Hard Blok. It's faster and less expensive.
I didn't think that a crack in the wall would be caused by freezing.
The warranty is long past expired or I'd take it back.
It could be sleeved, but I just thought I'd ask about Hard Blok. It's faster and less expensive.
I didn't think that a crack in the wall would be caused by freezing.
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Car: Different One Every Day
Engine: LS1,LS6,L98,L83
Transmission: 700R4, 4060E,Turbo 350, Turbo 400
Freezing is a LOT like lightning.
It will bust the block WHEREVER it wants to.
Sleeve it or find another block.
The filler probably can't be relied on 100% to seal it up correctly.
It will bust the block WHEREVER it wants to.
Sleeve it or find another block.
The filler probably can't be relied on 100% to seal it up correctly.
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Car: '85 IROC
Engine: LB9
Transmission: 700 R4
I've made up my mind that I don't want to fix it.
But before I put it on the scrap heap I'm going to do an experiment with some Hard Blok....
This engine I'm working on is an example of why not to go looking for the best "deal" when shopping for a shortblock.
The cyls were honed without a torque plate
The lifter bores weren't honed
It wasn't cleaned thoroughly
The timing chain rubbed on the block
It's cracked
The starter mounting pad is worn crooked
It had the wrong rings for the cyl finish
The crank is .003+ bearing clearance
I ran it for 2 hrs on a test stand and noticed that two pushrods weren't spinning and decided to tear it down and found that it was on the path of self destruction from some cheap timing chain that came with it that didn't clear the block, and filled it with chips.
I learned what cyls look like when they haven't been torque plate honed.
There were 5 shiny spots on the bore of each cyl, spaced between the bolts.
I'm gonna fill one side of the block halfway with Hard Blok and hope that it holds long enough for me to build a real engine.
But before I put it on the scrap heap I'm going to do an experiment with some Hard Blok....
This engine I'm working on is an example of why not to go looking for the best "deal" when shopping for a shortblock.
The cyls were honed without a torque plate
The lifter bores weren't honed
It wasn't cleaned thoroughly
The timing chain rubbed on the block
It's cracked
The starter mounting pad is worn crooked
It had the wrong rings for the cyl finish
The crank is .003+ bearing clearance
I ran it for 2 hrs on a test stand and noticed that two pushrods weren't spinning and decided to tear it down and found that it was on the path of self destruction from some cheap timing chain that came with it that didn't clear the block, and filled it with chips.
I learned what cyls look like when they haven't been torque plate honed.
There were 5 shiny spots on the bore of each cyl, spaced between the bolts.
I'm gonna fill one side of the block halfway with Hard Blok and hope that it holds long enough for me to build a real engine.
#7
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Car: 83Z28 HO
Engine: Magnacharged Dart Little M 408
Transmission: G Force 5 speed
Axle/Gears: Moser 9" w/Detroit Trutrac
I've made up my mind that I don't want to fix it.
Why even waste more money on Hard-Blok?? I mean, do whatever you wish but I myself would just count my losses and get another block.
Sounds to me, and no offense intended - You're trying to polish a turd. 350 blocks aren't hard to find, nor are they very expensive.
- Jeff
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Car: '85 IROC
Engine: LB9
Transmission: 700 R4
Just don't buy a shortblock from Lansing Engines, or some other engine rebuilding sweatshop... And you won't be faced with having to make the decisions I'm making right now.
I've been riding my bicycle for 5 mo now.
I can polish this turd, and have four wheels in 2 or 3 wks.
Or I can do without for another 8-10 wks while I'm building a better engine.
... Why am I sitting here burning up time to try an explain all this???
I have a turd that needs polishing ! ! !
I'll be in the garage
I've been riding my bicycle for 5 mo now.
I can polish this turd, and have four wheels in 2 or 3 wks.
Or I can do without for another 8-10 wks while I'm building a better engine.
... Why am I sitting here burning up time to try an explain all this???
I have a turd that needs polishing ! ! !
I'll be in the garage
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Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
That sucks Bert, i know how it feels! I bought a 350 block from the JY a couple of years ago, pulled it all apart, and was like awesome i'm gonna build me a 383. About a year later after the warranty expired and i had my money saved up, i go out there and check it out. There was and 1.5" crack in the lifter valley, i was like damn! So a year later i buy another block from a friend, but decided later to just go LS1.
So now i got a couple cranks, 2 sets of rods, some 993 heads, and a block i got to get rid of.
Its cool though i got 15 pistons, i am going to melt down and cast some sculptures.
Some times i question myself!!! :lala:
So now i got a couple cranks, 2 sets of rods, some 993 heads, and a block i got to get rid of.
Its cool though i got 15 pistons, i am going to melt down and cast some sculptures.
Some times i question myself!!! :lala:
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Car: '85 IROC
Engine: LB9
Transmission: 700 R4
Thanks for the words of support Leigh.
There is a silver lining to be found in this dark cloud.
For one thing, now I'll have an engine that's expendable.
A guy gave me some barely used or slightly damaged hyd flat tappet cams that I've wanted to test. This will be an opportunity for that.
And I've actually rebuilt engines that were a lot more messed up than this one is and had them last for quite a while.
There is a silver lining to be found in this dark cloud.
For one thing, now I'll have an engine that's expendable.
A guy gave me some barely used or slightly damaged hyd flat tappet cams that I've wanted to test. This will be an opportunity for that.
And I've actually rebuilt engines that were a lot more messed up than this one is and had them last for quite a while.
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