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Great process and quality control GM...

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Great process and quality control GM...

Postby needforspeed66gt » Tue Jun 25, 2013 7:51 pm

Inexcusable amount of core shift on a $22k LS9 crate engine.

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Re: Great process and quality control GM...

Postby lorax » Tue Jun 25, 2013 8:15 pm

I guess it could be worse. It could be in a $113,000 Vette.
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Re: Great process and quality control GM...

Postby ProPower engines » Tue Jun 25, 2013 8:58 pm

That's no surprise!!!
All the crate engines are built with reject parts taken from the production line floor that would not be used in a vehicle that would be sold with the new longer warranties available now.Could you amagin taking the engine back to the delaer if it was installed in a vehicle to get warranty on that after a couple years on the road.
Thats why theres a very limited warranty on crate engines and thats why under the warranty they would determine that abuse and neglect would cause that if the engine failed and the owner would get squat.
They know that the HP level is better then a production vehicle would have and thats how they get rid of reject parts by selling crate HP engines. How is the rest of the engine?? Not that it matters at this point you still need a block.

I had an iron headed crate in here last week with valves that never sealed from day one. And 10k later they needed a valve job and they did not even install the oil shields on the valve springs.

It was a 290HP TBI crate for a PU 95 truck.
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Re: Great process and quality control GM...

Postby SLPRACINGENGINES » Tue Jun 25, 2013 9:05 pm

i have saw core shift so bad in the older 350 blocks.i had one that a guy dropped off to me to tru bore the lifter bores trhat i had to custom make a set of slugs to put in three of the lifter bores to get them to be right.
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Re: Great process and quality control GM...

Postby needforspeed66gt » Tue Jun 25, 2013 9:30 pm

ProPower engines wrote:That's no surprise!!!
All the crate engines are built with reject parts taken from the production line floor that would not be used in a vehicle that would be sold with the new longer warranties available now.Could you amagin taking the engine back to the delaer if it was installed in a vehicle to get warranty on that after a couple years on the road.
Thats why theres a very limited warranty on crate engines and thats why under the warranty they would determine that abuse and neglect would cause that if the engine failed and the owner would get squat.
They know that the HP level is better then a production vehicle would have and thats how they get rid of reject parts by selling crate HP engines. How is the rest of the engine?? Not that it matters at this point you still need a block.

I had an iron headed crate in here last week with valves that never sealed from day one. And 10k later they needed a valve job and they did not even install the oil shields on the valve springs.

It was a 290HP TBI crate for a PU 95 truck.


Intake guides were totally smoked after minimal hours, I'm told this is a very common issue with these motors because GM specified too rough of a surface finish on the Ti valves. In every other application the factory GM powdered metal guides show very minimal wear even after tens of thousands of miles.

Other than that it was in relatively good shape considering that the owner fully submerged it in muddy water and then continued to beat on it in a couple more competitions until it had no compression. The motor is in an off-road top truck challenge buggy, pulled the top off the supercharger and there was sandy mud all over the intake ports and in the intercoolers. :lol:
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Re: Great process and quality control GM...

Postby GARY C » Tue Jun 25, 2013 9:47 pm

I guess they don't do their 50 hour endurance test know that they are owned by the Union!
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Re: Great process and quality control GM...

Postby ProPower engines » Wed Jun 26, 2013 2:59 am

Intake guides were totally smoked after minimal hours, I'm told this is a very common issue with these motors because GM specified too rough of a surface finish on the Ti valves. In every other application the factory GM powdered metal guides show very minimal wear even after tens of thousands of miles.

Other than that it was in relatively good shape considering that the owner fully submerged it in muddy water and then continued to beat on it in a couple more competitions until it had no compression. The motor is in an off-road top truck challenge buggy, pulled the top off the supercharger and there was sandy mud all over the intake ports and in the intercoolers. :lol:[/quote]


Have you ever had the chance to measure the stem clearance on a new head??
It may also be from too much stem clearance allowing the valve to rock in the guide causing the excellerated wear and also maybe to stiff of stem seal. Like the old style nylon seals that would wear the stems beyond reuse
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Re: Great process and quality control GM...

Postby POS Dakota » Wed Jun 26, 2013 5:22 am

No matter how you stack it, I could never just drop a crate engine into my car and go without having things like this in the back of my head.
At that point it just makes sense to build it yourself after careful inspection of the parts.

Kind of silly seeing this on an ls9 where the user is almost guaranteed to turn it up. :lol:
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Re: Great process and quality control GM...

Postby Truckedup » Wed Jun 26, 2013 7:20 am

Sloppy GM core shifts and machining is nothing new.I was building a 50's GMC 302 inline 6 for performance. The lack of stamped numbers meant this was a replacement short block.The standard bores were off their centers,the block deck tilted side to side and front to back,the connecting rod centers varied about .006. But the main bearing bores were perfect....The engine will function as intended ,but.......
The last years of GM 250 inline engine had an HEI ignition.Many of the HEI's have a U joint on the shaft. A U-joint? A GM power plant engineer told me the machining was so sloppy the distributor bored hole was cocked causing warranty issues with worn distributor bushings.The U joint was an easier fix than trying to get the tooling sharpened and set up correctly.
I heard that it was common for GM to use dull or poorly set up tooling .These orders came from management trying to save a few cents. I'm sure the other auto makers did the same but GM was the biggest so it made more sloppy stuff.
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Re: Great process and quality control GM...

Postby swatson454 » Wed Jun 26, 2013 7:24 am

Oh, well isn't this just fantastic news. I "scored" a standard bore, 4 bolt, Vortec roller block from a ZZ4 crate that developed a rod knock around 20k miles. Thanks a pant load for the vote of confidence :lol:
Last edited by swatson454 on Wed Jun 26, 2013 8:07 am, edited 1 time in total.
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Re: Great process and quality control GM...

Postby stealth » Wed Jun 26, 2013 7:58 am

These decisions to use up inferior parts are usually made by people so far up the ladder in management they don’t even know what they are signing off on….but they know the cost savings will look good on a chart and for their career.

Typical of many companies….
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Re: Great process and quality control GM...

Postby mtkawboy » Wed Jun 26, 2013 9:43 am

Am I the only one that sees the picture so large I cant even tell what Im looking at ?
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Re: Great process and quality control GM...

Postby blykins » Wed Jun 26, 2013 9:53 am

Look at the sleeve thicknesses.
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Re: Great process and quality control GM...

Postby DaveMcLain » Wed Jun 26, 2013 10:37 am

It seems obvious to me that the sleeves are installed and then bored on centers in a difference process. As long as the wall thickness is thick enough what does the picture show us that hurts anything?
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Re: Great process and quality control GM...

Postby Dave Koehler » Wed Jun 26, 2013 11:47 am

It will be interesting to know if the finished bore is in it's blueprint position or someone really goofed.

Pontiac is the one that always puzzled me. Line honed main bores but rod bores machined with a hatchet. :shock:
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