From Blown Block to Beast: Reviving a Destroyed LS3

This LS3 had two holes in the block but now it performs like a factory-fresh engine.

Buying a cheap C6 Corvette Grand Sport with a blown engine is a risky proposition. You could be getting the deal of a lifetime or setting yourself up for a future of heartbreak. And often there is only one way to find out what your fate will be. That is to jump right into the project and see what’s what. That is exactly what Alex Palmeri of LegitStreetCars did once he bought his Corvette with a ruined LS3. He documented the work in a recent video posted to his YouTube channel.

It all started when someone apparently overfilled the LS3 with oil. That caused the engine to hydrolock and it then snapped a connecting rod. That is bad, but not the end of the world. The rod can be replaced fairly easily. You just have to hope that the block wasn’t damaged. Unfortunately for Palmeri, the LS3 had not one but two large holes in the block. That could have been game over. But a master welder friend managed to weld the block back together. The question now is, would the block hold up?

The Rebuild

The cool thing about the LegitStreetCars YouTube videos is that they usually clock in at around one hour in length. And there isn’t much goofing around and filler during that time. Palmeri and his team spend the time working and showing all the details. It is fantastic for those that like to get into the nitty gritty.

That being said, we are not going to touch on everything that was covered in the video, so watch it for yourself if you want all the details. Long story short, after the block was welded up the engine was put back together in a better-than-factory rebuild process.

Did it work? Well, the dyno doesn’t lie.

Dyno

A lot of work went into this LS3 before it was ready to be installed in the C6 Grand Sport and hooked up to the dyno. The engine had to be rebuilt and then checked to see if it would hold oil pressure. Once that was sorted it was time to start the car and fill the shop with smoke.

There was a lot of oil to burn off, but the smoke was nothing to really be concerned about. Next it was time to bolt on all the ancillaries and get the Corvette on the road. It was critical to get some miles on the engine before strapping it to the dyno.

Finally, the big day arrived and the LS3 didn’t disappoint. It made 405 horsepower at the wheels. This is a stock LS3 Corvette with the only modification being a Borla exhaust. Not bad for an engine that had two giant holes in it not that long ago.

The Drive

Now that the car is broken in and tested on the dyno, it was time to have some fun with it. That is what a Corvette is all about. It looks great on the road and sounds proper thanks to that rebuilt American V8 under the hood. The C6 Grand Sport is a desirable car, and that is proven by the fact that this very car was already sold to a man in Texas. He should have years of driving bliss ahead of him and the Swiss cheese engine block is a thing of the past.

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Joe Kucinski

Joe has been obsessed with cars since he got his very first Matchbox toy in the 1970s. In 2003, he found a new obsession in track days that led to obtaining his SCCA competition license in 2015. In 2019, he became a certified driving instructor for the National Auto Sport Association. His love for all things four wheels has never wavered, whether it's driving some of the best cars in the world on the racetrack, tackling 2,000-mile road trips in 2-seat sports cars or being winched off the side of a mountaintop in a Jeep. Writing for the suite of Internet Brands Auto Communities sites, including Rennlist.com, Ford Truck Enthusiasts, 6 Speed and more allows him to share that knowledge and passion with others.