Check out this customers LS7 that was put together by some hacker shop in SoCal:


Number 8 totally destroyed


Number 8 chamber with both valves MIA


Number 7 chamber


Number 7 piston MIA



Intake contained at least 1 Lb of piston and cylinder wall debris



Debris in oil pan







2 Clutch pressure bolts backed out until one thread, the others loose

 

Wow!!! And I thought mine looked ugly..... I can't believe those connecting rods are still in one piece but the pistons and half a cylinder wall are completely GONE!!

Mike

 

what shop? i just ask because i might want to avoid them.

 

good Lord!

 

Not sure who it was but I will find out.

 

Bummer for that dude

 

talk about a light weight rotating assy......

 

Isn't that the same one that had chunks of the piston come out in the exhaust???

 

man i feel sorry for that guy.

 

I see more and more of that poor quality workmanship, not just from backyard techs but from shops. Bolts missing or not tight, parts missing, incorrect repair procedures. I just finished a car for my friend who let his neighbor fix the bent valves on his Prelude, the guy put the headgasket on backwards, didn't clean bolt holes, torque was way off, just a horrible job. Maybe it's a sign of the times, (unemployment) there is no excuse. I'm dissappointed to see customers ripped off, it reflects on the whole industry, even techs that do quality work as yourself.

 

SO have you figured out what caused it to come apart? Good carnage photos but what really happened ?? Couple loose pressure plate bolts doesn't mean the shop who did it destroyed the engine. Did the customer put his own clutch in?

We see a lot of poorly built engines that we repair but some of it is customer fault. What did the shop do? Did they build the whole engine or just install and tune it? Was the customer running a 300 shot without a tune? Lot of factors can be at play but we don't know any of them from a few photos. Certainly wouldn't be the first time a pressure plate bolt backed out but we need to know more of the story before condemning someone.

There is more to any story than meets the eye.

 

The owner is a college student in Irvine, lives in a apartment with no garage, he didn't do any of his own work and relied on the shop to do. The shop he took it to did all the work, clutch install, headers, cam install and tuning. Got him for several thousands of dollars. Sold him SH*T headers that were tri y design, their tune was so far off before the engine went away that it wasn't even in the state let alone being in or near the ball park. Figures seeing how the owner told me that the shop didn't have a on site chassis dyno and had to go to another shop for dyno time.

From what I have see in the engine, it appears that the most likely cause of the destruction was a valve dropping or detonation leading to piston destruction that lead to breaking off a two exhaust valve heads and one intake valve head. Or the at least one exhaust valve or the intake valve breaking causing the events. What caused the valves to break is any ones guess, could have been from the pistons coming apart, if that is the case what caused the pistons to come apart, the PCM cal is the likely suspect, or it could have been that the valve just broke who knows, at this time its like which came first the chicken or the egg? I do know for sure that their engine cal was totally screwed up, way too much timing for a LS7 and their PE fueling was way off, pig rich in the bottom end to the extent that it would nearly peg my AFR meter on the low end and quite lean on top to the tune of 13.6 while that isn't extreme its way too lean for my taste.

The loose clutch bolts didn't cause the problem but had the engine lived they would have resulted in a clutch and or flywheel failure or worse case scenario a high RPM failure leading the clutch componentls coming off the flywheel in a catrastrophic chain of failures leading to parts ejecting through the thin wall bellhousing and into the passenger compartment causing personal injury. I hope that shop has a good insurance policy!

The new engine is installed and running, the car is waiting for the owner to either pick it up or arrange shipment to Irvine. The new engine was built with a new LS7 block and a Callies rotating assembly with Wiseco pistons, with custom CNC ported LS7 heads loaded with GM Ti intake valves and Ferrea one piece exhaust valves. Its making shy of 550 to the wheels which I attribute to the tri y headers, if he had some decent ARH or similar headers there is more in the engine, this same build in another C6 with ARH and a Corsa rear section made 570.

 

Another reason why ALL LS owners should bring their cars to only you

 

Ahh so it was a tuning issue. Looks like the car was under boost It unfortunately does happen, there are plenty of shops out there doing shotty work

We got a LS7 427 we 're turning into a 457 that made 525 at the rear wheels (C5 Z06) with cnc ported LS7 heads and good long tubes and burned a quart of oil every 300 miles or so. Was a complete longblock bought and paid for in cash for about $13,500
This is a very popular shop is all I can say without getting into trouble on here.
Most bizarre hone job he has ever seen is what Erik said once he got it apart. (production shop engine)

It will get done right this time and we're looking for 600+ depending on how the customer wants it cammed.

 

Same shop that built the oil burner I installed last year by chance? And is there a guy name that starts with a "B" that works there?

 

No but he was the MTI connection in Mikeys oregon guys post

 

Nice motor Tom! You gonna cut the 2 cylinders off the end & sell it as a V6?

 

TJ didn't you think that it might have been a cam timing issue? I have a theory that there might have been a mechanical issue and they richened it up down low for drivablity and leaned it out and added timing trying to make up for the lost power.

 

id be very upset if that was mine, MIA pistons are never good i have a buddy that just bought an 02 ws6 with a BLOWN UP ls1, it had 2 MIA pistons the escape route was definetly the oil pan because there wasnt much of the pan left

 

Surprisingly, the cam was installed correctly. Its very hard to say what happened, the suspicion now is that an exhaust valve lost its head and started the catastrophic failure into motion

This one had a couple escape routes, some debris entered the oil pan, a very small amount exited the side of the block above the starter, a few peices of the piston blew out the tail pipe, and there was a large amount of debris in the intake manifold about equal to what I found in the oil pan. All of the debris was piston material and three valves, two exhaust and one intake heads.