LC2 Buttom End Engine Build - Power Trip

Mmm, roller cam. When discussing rollers, there are two types to get familiar with: aus-tempered, and billet. Years back econo rollers gave all rollers a bad name, as inferior materials caused them to fail. That's why you may hear "billet or nothing" when someone's picking out a roller cam. However, the aus-tempered process creates a very strong core to start with; it's not as strong as a billet roller, but it's a couple hundred bucks cheaper and will be more than strong enough for a build like this. Our new aus-tempered roller and a matching valvetrain is going to increase the 231's usable rpm limit from the low five grand range to over 6,000.

With these high-boost Buick engines, the factory hypereutectic pistons should always be replaced with a quality, forged set. For this build, we chose custom .005 over (3.805) JE Pistons. Hartline uses this size because most of the blocks that he runs across will clean up at .005--this minimizes how much boring you need to do to have fresh holes, and allows for more boring down the road. On top of that, "Even though I can't quantify this with a gauge, I have a feeling that the smaller the bore is, and the thicker the cylinder walls are, the cooler the engine runs overall."

Here's the underside of a Buick V-6 JE. The dish diameter of these custom pistons is slightly larger than the off-the-shelf 3.820/3.830 parts. That means they are lighter than the standard JEs: 470 grams per piston, as opposed to around 540 for the shelf JEs. "That is a big weight difference," JE's Tech Salesman Alan Stevenson states, "and this lighter piston will see substantially lower inertial forces, which will result in better connecting rod, crank, wrist pin, and rod bolt life expectancy. As far as the material, JE uses a 2618 aluminum alloy that is the industry standard, and this is the best performing alloy that is still affordable. What makes this piston among the best out there is that JE is able to manufacture pistons to keep the ring grooves flat. Simply put, the flatter the ring groove, the more horsepower you can make. Also, skirt shape is critical, and we think JEs are some of the most accurate." Additionally, the JEs have an oil passage that feeds oil scraped from the rings to the wrist pins.

Our custom pistons came with full floating pins, dual spiro locks per side (more difficult to install, but proven to provide the best wristpin retention at a reasonable cost), upgraded high-strength chrome bar stock wrist pins, rings, and the pin-fit option. Cal has assembled all of the rod/piston combos and laid out the 3.8's parts in preparation for assembly.

With the RJC main cap studs and bearings installed, Hartline begins by oiling up the bearings and placing the crankshaft in.

The thrust bearing is oiled up next and installed.

A rubber hammer is used to tap it in securely.

The RJC Racing girdle is test-fit at this point; the timing cover slides in from the front, and it doesn't allow you to get a good seal between the girdle and cover if the girdle goes on first.

In a big boost 10-second build, the 109 block will be stronger--and last longer--with some structural reinforcement. One of the great new products for TRs is RJC Racing's block girdle. It is made from .75-inch thick, 1018 billet steel and CNC machined for an exacting fit. RJC has customers who run reliable low 9s with a girdled stock block, so this should be more than adequate enough for this engine.

An initial check of the crank endplay is made--Cal is looking for about .006 clearance here. The rest of the caps are installed and torqued to 100 ft-lbs.

The JE rings were file-fit before the installation started. We're using 1/16 top, 1/16 second, and 3/16 oil JE rings, which are a good compromise between sealing and friction in this high-boost application.

The block is flipped over, and Cal installs the pistons and rods using a Tavia cone-shaped ring compressor.