Way back in our Dec. '07 issue, we ran an article that provided a thorough look at the LT1, Chevrolet's engine that bridged the gap between the original small-block and the company's current Gen III and IV family of engines. For its time, it was very advanced, utilizing reverse flow cooling, improved cylinder head design, and sequential fuel injection ('93 and later). The LT4 variant improved on the recipe even further with an aggressive cam profile, even better heads, and a lightened valvetrain. Some of these innovations became standard equipment on the forthcoming LS1. But the LT production run was limited to just six years between 1992 and 1997, meaning the number of these engines and the parts available are much fewer than the Gen I small-block and the LS engines as well.
So, based on the limited appeal of this engine, who, if anyone, should care about this article? Anyone who owns or is considering buying a fourth-gen Camaro or Firebird, C4 Corvette, or Impala SS. Plus, some restomod guys are swapping LT1s into older GM muscle cars because they drop right in place of a standard small-block without all the fiddling you have to do to get an LS engine in.
So, here's the deal: We scored an LT1 out of a '94 Caprice police car with the intention of rebuilding it and bolting parts onto it to find out the potential of these engines. Here's how it went down.
If our engine looks a little crusty, that's because it is. This is a high-mileage unit out of a 9C1 Caprice that saw hard time first as a police car and then as a taxi cab. The car had more than 225,000 miles on the clock when we pulled the engine. B-body trivia experts will note that our engine has aluminum heads instead of the factory iron heads. Before we bought the car, someone installed Edelbrock heads but never ran the car with them. More on that later. We took it to our buds at JMS Racing Engines for a teardown and inspection. We wanted to rebuild this engine as cheaply as possible, reusing as many of the stock components as we could.
During the teardown, we encountered the normal stuck fasteners. One of our flexplate bolts was seized, and the head of the bolt rounded when we tried to unscrew it. Though we tried special sockets, we eventually had to chisel it off.
LT1s have a unique, press-on balancer hub that requires a special puller. In a pinch, you can remove it with an air hammer.
We were encouraged by the cleanliness of the bores and hoped to get away with just replacing the rings and bearings.
Our hopes were dashed when we checked the thrust flange on our crankshaft. It was worn so badly that the crank was unusable. JMS' Jeff Johnson said this is a common problem.