Caught in the Cross-Fire

The engine was complete with...        read full caption The engine was complete with all the emissions equipment still intact. All of this will be reinstalled onto the new engine and will only add to its “original” look.

The first step in the transformation...        read full caption The first step in the transformation is to remove the old engine. Even though we’re going for more power, we’ll be using many of the parts you see here. Some parts will have hidden modifications; others will only be cleaned and reused.

While the engine was at the...        read full caption While the engine was at the machine shop, we took the opportunity to clean up the engine compartment. There’s no better time, and the end result is well worth it.

We’ll also be changing...        read full caption We’ll also be changing the computer in the car. Chris has found that the easiest way to make the necessary changes is to remove the side cover of the console and the seat. This gives you room to work while minimizing the chance of breaking anything.

This is what you’ll find...        read full caption This is what you’ll find stashed in front of the battery in the compartment behind the driver seat. (Whose idea was that anyway?) The ECM, fuel pump relay, electronic spark control module, “E” cell timer module (turns on Service Engine Soon light at 60,000 miles), and the ECM/fuel pump power fuse are all tucked away in this compartment. The “E” cell timer module was the only part we removed. We’ll be changing the ECM to a ’90 Camaro (VIN code E) computer. This is the computer for a throttle-bodied 305, V-8 Camaro. While we’re doing this swap on an ’82 Corvette, it will also work on an ’84 with either an automatic or a 4+3 trans. One of the benefits of swapping to the Camaro ECM (PN 01228746) is a faster processor, and the chip can be reprogrammed, whereas the ’82 PROM was a one-time burn.

You’ll need to change...        read full caption You’ll need to change the connectors to fit the newer ECM. They will now be one 32-pin and one 24-pin instead of the edge-board connectors that were on the ’82 ECM. You’ll also need to change the position of some of the wires and run a jumper for each of the injector drivers. NAPA has the metal connector terminals, and you can get the plastic connector at a salvage yard; or Chris can supply the connector, terminals, pliers, and diagram for the wire changes.

Originally, the fuel pump...        read full caption Originally, the fuel pump and ECM both used the same fuse. Chris clips the fuel-pump wire and installs a weatherproof, fuel-pump-dedicated, 15-amp fuse and holder, and installs a 10-amp fuse for the ECM.

There are a lot of wires here,...        read full caption There are a lot of wires here, and Chris suggests you take your time and double-check your work. If you hurry through this step you’re only asking for trouble. When you clip the wires, make sure to keep all the wires the same length to ensure the installation is clean when you’re finished.

When the engine came back...        read full caption When the engine came back from the machine shop, Corvette Clinic installed TRW forged pistons and a Comp Cams roller camshaft. With a roller camshaft, you need to use a cam button on the front of the camshaft to keep the cam positioned. Watch the clearances between the cam button and the timing-chain cover. Machine work may be needed to get the proper clearance.

To complete the valvetrain,...        read full caption To complete the valvetrain, we used Comp Cams roller-rocker arms, 1.6 intake and 1.52-ratio rockers on the exhaust, coupled with Manley

The biggest hindrance to performance...        read full caption The biggest hindrance to performance with the Cross-Fire engine is the intake. Chris improves the intake by removing the diffusers under the throttle bodies and enlarging the holes in the intake cover. Also, the bottom end of the ports are very restrictive, and Chris opened them up to match the size of the ports in the heads. In the photo, the area from Chris’ finger to the top of the port was initially filled with casting. With the porting finished, the heads were Extrude Honed for maximum flow.

We contacted Turbo City to...        read full caption We contacted Turbo City to bore out our throttle bodies. They also provided us with 68-lb/hr injectors and an adjustable fuel-pressure regulator so we could trim the fuel for optimum performance.

Chris rebuilt the throttle...        read full caption Chris rebuilt the throttle bodies using the GM Throttle Body Service Kit (PN 17079729), and there is little evidence of the modifications that are within.

With the entire engine assembled...        read full caption With the entire engine assembled you can see how clean and detailed everything is. Just like a new Cross-Fire.

We used an Edelbrock water...        read full caption We used an Edelbrock water pump and left it the natural gray, which looks great on the front of the engine. Another finishing touch is sandblasting and clearcoating all of the shielding. Make note of the routing of the front two spark-plug wires through the shielding and UNDER the new motor mount. It is well worth the effort because it prevents the plug wires from getting burned.

We used an Edelbrock water...        read full caption We used an Edelbrock water pump and left it the natural gray, which looks great on the front of the engine. Another finishing touch is sandblasting and clearcoating all of the shielding. Make note of the routing of the front two spark-plug wires through the shielding and UNDER the new motor mount. It is well worth the effort because it prevents the plug wires from getting burned.

We contacted Yank Converters...        read full caption We contacted Yank Converters for a converter matched to the torque curve we were building into the engine. Select your converter carefully because a torque converter can either enhance a camshaft selection or make it nearly impossible to drive. Make sure to fill the torque converter partially so it isn’t run dry when you fire the engine.

When installing the torque...        read full caption When installing the torque converter, turn it back and forth a few times while pushing in to fully seat the converter into the pump. When the converter is seated fully you won’t be able to put your finger between the converter and the pump housing, as evidenced in this photo.

We put the flywheel on the...        read full caption We put the flywheel on the engine and set it into the Corvette. Take your time and make sure the engine doesn’t tear any wires loose as you lower it because you won’t find out they’re damaged until you try to connect them. Then you have an engine in the way. Also, if you don’t have the torque converter seated properly, you’ll never get the engine and transmission to seat properly.

We also changed the ECM coolant...        read full caption We also changed the ECM coolant temp sending unit to the newer style which uses a more reliable connector.

Next it was time to hook up...        read full caption Next it was time to hook up the fuel lines and linkages.

As mentioned previously, we...        read full caption As mentioned previously, we installed the air pump and all of the emissions equipment. The only change we made was to move the oxygen sensor to the front of the Y-pipe, just after the exhaust manifolds.

We used a new distributor...        read full caption We used a new distributor cap, rotor, and coil. It would be silly to do an engine rebuild without doing a tune-up of the ignition.

We had a few wiring issues....        read full caption We had a few wiring issues. We needed to replace this connector for the starter. A bad connection caused it to overheat and melt. You can’t be sure of ever getting a good connection unless you address a problem like this. Also, because we separated the grounds at the ECM, we needed to connect another ground onto the connector at the firewall under the hood. Without this, the fuel pump wouldn’t have a proper ground and would not operate.

Because the hood-vent solenoid...        read full caption Because the hood-vent solenoid was operated from the ECM and the new one doesn’t have that capability, Chris made a bracket and installed a micro-switch to operate the vent at wide-open throttle. Also, Chris installed the Intake Air Temperature sensor for the ECM into the bottom of the air cleaner. You can see it through the opening between the air filters.

The final steps of installing...        read full caption The final steps of installing the exhaust, double-checking wires, and filling the fluids were close at hand. At this point we were anxious to see how much better this ’82 was going to perform.

Whether it merits it or not, the Cross-Fire engine’s performance often gets a bum rap. That’s not always a bad thing, though. Let me explain. With the competition looking down their noses, the element of surprise is that much more potent. That’s what Steve Oktela is hoping for. He took his ’82 Corvette to the Corvette Clinic with the expressed goal of turning up the torch in his “Fire,” but he still wanted to retain the stock look. That’s exactly what they did.

When looking at the engine, there aren’t many hints of anything other than stock parts hiding under the air cleaners. That all changes when you hit the gas. This Cross-Fire will churn the tires at any stoplight. We intend to take the car to Norris Motorsports in Ocoee, Florida, for some dyno time. To see what horsepower our new engine is capable of dishing out, we’ll have dyno numbers posted next month in Inside Track.