C3 Big-Block Engine Swap - Big-Block Party

Installing an injected Rat motor for improved performance, fuel mileage, and driveability

Paul Sisia Aug 1, 2011 0 Comment(s)
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First Steps
Make it easy on yourself. Before trying to remove the engine and trans, take the time to remove all of the bolt-on items that get in the way. The air cleaner, carburetor, distributor, exhaust manifolds, A/C compressor, alternator, power-steering pump, cooling fan, and all the pulleys add weight to the engine. Remove the starter as well. And don't forget to drain the engine oil, the transmission fluid, and the coolant from both the radiator and the block. (There are small drain plugs on each side of the block for this purpose.)

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It only takes about two hours to remove all of the above items, and no special tools are required. A set of open-end wrenches, screwdrivers, and a socket set will do the trick.

While you're at it, take particular note that the radiator can easily be damaged. To avoid this, remove the top and bottom hoses, the two bolts that hold the top of the shroud to the core support, and the two nuts on the bottom of the shroud (one on each side). Finally, remove the shroud and lift the radiator straight up and out.

Before we got too far, Fulcher was quick to point out an item unique to Corvettes: the engine ground straps. They'll also need to be disconnected before trying to pull the engine.

Fortunately for us, the Jim Ellis Corvette Center had all the tools required to handle the heavy lifting, too. An engine hoist, a hydraulic transmission jack, and a pneumatic ratchet should make the removal a snap.

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With the engine and trans out of the way, it was time to make a quick assessment of any other areas that might need to be addressed. Big-block springs, some new upper and lower control-arm bushings, and a better cooling system were obvious, but we'd also need to make sure the rear differential could handle the tremendous twist generated by the new powerplant. But before we started on any of that, we sent the car to the paint-and-body shop to clean, prep, and paint the engine compartment.

Detailing the Engine Compartment
This Collision Center handles repair for all of the Jim Ellis dealerships, including Porsche, Audi, Saab, VW, GMC, Buick, Hyundai, and Mazda. Needless to say, it's a huge, state-of-the-art facility with new Porsche Panamera Turbos and GT3s, Audi R8s, ZR1 and Z06 Corvettes, and a sea of other cars in various stages of collision repair. After we met with the Center's director and outlined the project, we spoke with the body-shop manager who would personally manage the entire process. He took a written, detailed account of the work to be performed and scheduled the initial prep to be done on one of the Center's hydraulic lifts.

Having the car up in the air made it easy to reach all the tight areas of the engine compartment, the frame, and the underbody. While on the lift, the Center's techs pointed out a few small holes in the footwell and the trans tunnel, and scheduled a body man to do these repairs first. They also allowed us to remove the upper and lower control arms, the rear diff, the trailing arms, and anything else we wanted to send out to have repaired, painted, or powdercoated. Special care was taken to mask off the engine bay and to "bag" the whole car to avoid overspray.

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Next, the engine compartment and underside were thoroughly degreased, scuffed, and sanded. Finally, these parts were rinsed clean before satin black paint was applied for an as-new finish.

Odds and Ends
Although the heart of this project is the powertrain swap, there are an awful lot of ancillary parts that should be replaced or upgraded while the engine and trans are out of the car. Now is the time to inspect the shocks and springs, the brake pads and rotors, all the rubber bushings and hoses, and so on. Take a close look at each item and decide if you want to replace it with stock hardware or high-performance aftermarket items. Then, make a thorough list of these parts.


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