Engine Swap Tips & Tricks - Tech Review - Turbo Magazine

It is no secret Japan has given us the short end of the stick for years when it comes to performance cars. It keeps all the good ones on its shores: Nissan Skyline GT-R, Nissan Silvias S-13 to S-15, Honda Accord Type-Rs, Mitsubishi Evolution models I through VII, the Mitsu GTO, Subaru's previous WRX, not to mention a grip of cool micro vans like the Honda MD-X and Step Wagon and the list goes on.

Well, Japan blew it--it made the underpowered piles we got too similar to their Rising Sun brethren and savvy enthusiasts have been shoehorning the big power engines into U.S models for nearly a decade. Yep, getting your kicks on Route 66 has never been so good, thanks to a multitude of intrepid entrepreneurs hauling over Japan-spec power.

In fact, things may be getting out of hand, with people swapping in Type-R engines without exploring other possibilities. "Even if you have all the bolt-ons, consider swapping to a ported head and get the same output as a Type-R for a fraction of the cost," says Brian Dunshie of Mantaray Motrosports.

"We sell a head package that makes 58 hp to the wheels on a SOHC 1.6-liter. If they want JDM, we have it all. Now a Type-R into a CRX makes sense on a number of fronts and anything with a DX emblem on it is also a prime swap candidate. The way we look at it, it's all about VTEC and turbos. If you can upgrade to a VTEC powerplant or turbocharged variant then you are on to something."

The power benefits of VTEC are obvious, but the parts support of the B18C is far greater than any DX engine. Also, the beauty of a turbo is it can be tuned to "make and take"--make more power and take more abuse. The kings of the power swap are Honda's B-Series in Civics and CRXs and Nissan's SR20DET in 240SXs or anywhere they'll fit.

But where there is a powerful engine, there is a way. The 2JZ-GTE is the most potent powerplant in import drag racing. Three of the five 6-second Pro cars run the Supra engine and the 2JZ brought home the class championship in Pro and Street Tire in the 2002 NHRA SC series. A trend we have seen is Lexus owners who are happy with the refinements of their cars, but a bit disappointed when they depress the gas pedal. The 2JZ in U.S. trim and in Japanese VVTi trim are popular power options. It should be noted that the VVTi swap works best with 1998-and-up cars originally outfitted with a six-cylinder engine. Other hot mods include dropping STi EJ20s into the American 2.5RS and even the WRX, as well as wedging a three-rotor 20B in a Mazda RX-7. The aforementioned swaps are relatively straightforward, either bolting directly in place or secured via aftermarket swap kits.

Whether you plan to turn the wrenches your self or hire out a shop for the transplant, there is a lot to consider when swapping; doing it correctly will cost money.

Once the engine is in the car, you're not home free. Truth is, the trip is just beginning. What about the tranny? We contacted Place Racing and quizzed technician Gilbert Garcia on some of the general rules of thumb regarding Honda engine swaps.

He says anyone swapping a Prelude H22A into any year Civic will need to include the Prelude gearbox. He also wanted to point out that the Prelude transmission is a cable shifted, hydraulic clutch proposition. A DOHC engine destined to be dropped into a Civic will also need the DOHC tranny. All B-series engines are compatible with all 1990-up Integra gearboxes.

When it comes to transmission configuration, manual is superior to an automatic. The automatics run an AP Controller that oversees shifts in the gearbox. Getting this interface to work with an engine swap is a wiring nightmare. If you're after performance, a manual tranny is the way to go. Place Racing makes kits for the conversion and pedal parts and other bits and pieces are easily attainable at a parts recycler for about $75.

Beyond the tranny, the proper ECU, wiring harness and injectors are all possible points of contention. The ECU needs the correct input from the sensors, which is made possible via the wiring harness, and the injectors and ECU must be electronically compatible.

The ECU is key for swaps that bring VTEC into the equation and as a rule it's all about OBD (On Board Diagnostics). You want to use an engine and ECU with a similar OBD status. As an example, let's look at the B16A. B16A engines from 1988 to '91 are non OBD; B16As from 1992 to '95 are OBDI and 1996 to 2001 B16As are OBD II. The ECU should be of the same years of production as the engine it's controlling. Most surplus engine depots include the ECU with the engine purchase; if not, it's wise to purchase the correct ECU outright.

As for harnesses, there are connectors for the VTEC solenoids, a pressure switch, activation switch and a four-wire oxygen sensor that must be present to get the job done. In 1988 to 1991 Si models, these connectors must be wired into the existing OE loom. DX models of this vintage are more involved as you're converting a harness for a two-injector, throttle body injection system into a direct-port EFI harness with four injectors.

Beyond accommodating the additional injectors, the harness will require an injector resistor, magnetic pickup and accommodations for a B16 distributor. In 1992 to 1995 cars, the DX model requires the same modification as previous Si harnesses. The EX harness only needs to accommodate a knock sensor. Confused? Place Racing has custom harnesses for most Honda swaps and, priced from $150 to $300, they are worth every penny.

On the injector side of the equation, stick with the units that came with the engine. If this isn't possible, here are some tidbits from Russ Collins of RC Engineering.

From 1988 to 1991, Honda injectors were low-impedance, peak-and-hold units. In 1992, Honda converted to high-impedance, saturated injectors in Civics and Integras. Preludes and Accords made the jump to saturated in 1996. This area is where novices can really find themselves in a world of hurt. The ramifications of choosing wrong are a burned-out injector driver, which means a new ECU will have to be acquired. In some cases, the injector(s) get fried and at the very least mismatched injectors will result in a check engine light and a poor-running engine. A more complete overview of stock injectors in a multitude of sport compact vehicles can be seen in the accompanying Stock Injector Spotters Guide chart.

As with any complex undertaking, planning is key. Know exactly what components you need for your swap, then shop around. At some engine depots it's meatball surgery; engines are cut out of the car so quickly, the engine harness can be sliced up, ditto the radiator hose (which you need in a B-series swap, as it's larger than traditional Civic hoses).

Other questions for the engine depot should include throttle cable (B-series is longer that a DX unit), A/C compressor (different bolt patterns), fuel lines, heater hoses, engine mounts, shift linkage and slave cylinders. The bottom line is, you need to understand all the components needed to pull off the swap. One way around this is to purchase the entire front clip. The motor is still "in" the car, so it should be truly complete and you should have access to all the tidbits needed to get you down the road.

A power swap can be an intricate and intimidating endeavor, but the payoff is tremendous. Know you options. Know when to go with OE parts; know when aftermarket shortcut kits will save you time and money. Having a grasp on what it takes in parts, time and money will make the transition to big-league horsepower a smooth trip, whether you are doing the swap yourself or if you're having a shop handle the job.

Popular WwapsEngine 1988-1991 Honda Civic/CRXB16A, B18C (Swap Kit) 1992-up Honda Civic B16A, B18C (Drop In), H22 (Swap Kit) 2001 Honda CivicK20 RSX (Swap Kit) 1990-up AccordH22 (Drop In) 1989-up Nissan 240SX SR20DET (Drop In) 1991-'94 Nissan Sentra SE-R SR20DET Bluebird (Swap Kit) 1992-up Mazda RX-7 20B 3-rotor (Swap Kit) 1992-up Lexus SC3002JZ-GTE Supra (Drop In) 1999-up Mirage4G63 (Drop In) 1985-'86 Corolla GTS 5AG, 3S-GTE (Swap Kit) Subaru RS2.5 EJ20 Lexus SC/GS3002JZ-GTE VVTi (Drop In) Mazda Miata 13B (Swap Kit) 1965-'70 Datsun Roadster LB20, SR20DE, SR20DET (Swap Kit) Datsun 510SR20, SR20DET (Swap Kit) 2002 Subaru WRXSTI version EJ20 (Drop In)

Crazy Swaps (we have seen) RX-7 2JZ-GTE Supra RX-7Buick Grand National Turbo 6 Porsche 911Chevy small-block V8 Porsche 911Mitsubishi 4G63 VW BusPorsche 3.2-L

Engine S13 SR20DET Donor Car Red-Top 1991-'93 180SX & Silvia Black-Top 1994-'98 180SX Displacement1998cc Bore/Stroke86x86 Compression8.5:1 Injector Size 370cc HP205 @ 6000 TQ203 @ 4000 Turbo SpecsT25 w/ 60-trim 56mm compressor wheel,62-trim
turbine wheel in .64 A/R housing, Datsun 510 AM Roadster DestinationU.S. 240SX S13 (1989-94)