Power Pages: 1994 Acura Integra LS

Bringing the B18B engine back from the dead

The Engine
In the last installment of the Integra LS Power Page (Issue #34, Jan 2002) we were unpleasantly surprised by the low baseline numbers on our test vehicle. Baselining at an anemic 105.5 hp, our Integra was definitely something to sneeze at--even after the bolt-on power adders strained to boost the weak motor to 110.0 hp flat. Noting the loose piston ring seal by excessive blow-by, we figured the motor was in desperate need of some reconstructive surgery. Rather than drop the non-VTEC block on its ear for a fresher (and more powerful) VTEC motor, we decided to contact JE/SRP to help us bring the B18B engine back from the dead.

Performance Components
The folks at JE/SRP, a popular aftermarket piston manufacturers, were happy to help us out of our dilemma and provided us with a set of Sportsman Racing Products pistons and a complete set of high-tension rings. Since JE/SRP stocks a complete line of popular shelf pistons, delivery was fast and we were able to get straight to work on our vehicle. The pistons, constructed of a silicone alloy, have all the available features of the most popular racing pistons: oil lubrication points, domed surfaces with precision valve reliefs and oil control and oil scraper reliefs. The best part is the price; with massive shelf quantities available the minute your engine blows up, SRP has managed to take the pain out of engine rebuilding. Our particular pistons have a higher compression ratio (10.5:1) to help out in the power department. After all, this engine is going to stay normally aspirated for the rest of its life.

With the motor back on the right track, the next logical step on the performance ladder was to continue increasing the efficiency of the airflow on the intake and exhaust sides. To this end we enlisted the services of DC Sports' stainless-steel 4-1 header. This header design uses longer exhaust runners to equalize the exhaust gas pulses, thereby minimizing reversion while maximizing flow. The unit is a one-piece, polished stainless-steel affair, using only the highest quality welding processes and flange materials. Like most DC Sports products, this baby is street legal so you can kick ass and look good while doing it, without a care for those doughnut-wielding law-enforcement officials. Next in line for the powertrain combination, we chose a component often overlooked by the street-driven bolt-on warrior--the ignition system. Adding extra fuel and air into your combustion chamber is pointless if your stock ignition can't keep up with the combustion demands. On that note, we contacted Direct Hits ignition for its proprietary ignition capacitance system. DH kits use a capacitor on each of the spark plugs to "hold" the electrical charge until it's needed, resulting in more complete combustion of the air/fuel mixture. The kits can be purchased with the capacitor, a set of modified plug wires and BOSCH spark plugs specifically designed to be used with the Direct Hits ignition.

Dyno Testing
Along with installing the pistons comes a whole slew of other procedures--basically, tearing down the entire block, having it machined to fit the pistons, replacing any old gaskets and whatnot, and reinstalling the engine in the car. All of this was done with the help of Jay, The Engine Building Guy, a San Diego native and local underground engine builder. After the initial break-in mileage, we started tinkering under the hood.

The first thing we noticed was the engine was loud when it was cold; it almost sounded like we were driving a Mitsubishi Fuso diesel truck. After reaching normal operating temperature, however, the piston knocking decreased to nil. With the compression this high, we knew that we were going to encounter some ignition gremlins, and they came in the form of a midrange-rpm stumble. Timing had to be fully advanced to 22 degrees on the timing light for the car to run properly. Because we didn't want this to skew the results of our test, we replaced the ignition wires. The stumble went away (just as we thought it would), and we set the timing down to 13 degrees (with a little compensation for the higher compression ratio). With all of that drama done, the car was strapped to the dyno and registered 123.8 hp with 118.9 lb-ft of torque, well above the measly numbers we registered before. Thanks a million to JE/SRP for getting our Integra back into the world of performance engine tuning.

The next installation involved the stainless-steel DC Sports header. Because the header is designed as one piece, installation was a little more difficult than a standard two-piece header. Temporarily removing the slave cylinder (12mm bolts) and the radiator bracket (10mm bolts) allowed us to get the header in place without doing any damage to the fit or finish. Once the header was in place and the slave cylinder and radiator returned home, we turned the wheels of the Dynojet to 126.1 hp and 116.4 lb-ft of torque. Overlaying the graphs shows that more power was gained in the 2000- to 4000-rpm region, with another overall gain continuing all the way to the redline from about 5500 rpm. Peak torque output decreased slightly, but range areas from 2000 to 4000 rpm and again from 5500 to redline were increased slightly. Since ignition timing had become an issue with the newly installed high-comp pistons, we opted for a performance bolt-on ignition system that would help clean up the sputtering and spiking of our new powerplant. The Direct Hits ignition kit came with new Bosch resistor-type plugs that we gapped at .032-in. for our normally aspirated motor. After the inline resistors were installed on top of the spark plugs, the engine ECU was reset (according to manufacturer specifications) and we ran the car on the dyno. We expected a much cleaner graph, void of the spikes, peaks and valleys that plagued our other graphs, and that's what we got. Peak power output rose to 126.9 hp, with torque maxing out at 116.9. However, looking at the graphs, you can see the power gain was pretty consistent across the board and, more importantly, helped eliminate a lot of the spiking we had encountered before.

Conclusion
Are you thinking of dropping in a motor and expecting a world of difference in power? If you are, take heed from this Integra Power Page test--it just goes to show you you don't always get what you bargained for. Oftentimes age and prior maintenance conditions can turn your motor into just another block of metal. Make sure you take the time to refresh the motor if you have a chance--the power gain will do you a world of good. Stay tuned for the last installment of our Integra LS Power Page as we add a set of camshafts to the mix and fine tune them to produce the maximum amount of power. In addition, we are going to figure out how to clean up the slight stumble between 4500 to 5000 rpm with the adjustable fuel pressure regulator and the cam sprockets. Stay tuned.