Thread: SR20 swap guide
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Old 07-10-2004, 08:57 AM   #2
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Re: SR20 swap guide

Here is the first column. Sorry but the pictures don't transfer, so if you want pics, go to the site.

Project 240SR
Part 1: Engine Swap Preparation

By: Joe Lu and Charles Johnson

With Project 240SR, we will be transforming a bone stock 240SX hatchback into a potent street weapon with a robust SR20DET transplant. We took a top-down approach towards this new project, first attacking the biggest and most costly modifications under the hood, and leaving all other areas completely neglected for the time being. In this installment, we will discuss several areas of engine preparation, which will make the SR20DET transplant both easier and more successful at the same time.

Having clocked mileage far beyond the century mark on the odometer, the tired KA24DE that took residence in our engine compartment was nearing the end of its useful life. Our first test drive in the KA24DE-powered rattletrap confirmed our suspicions and was enough for us to begin making phone calls almost immediately after receiving the title. After several phone calls and a week of research, we turned to Marco Vargas at, who carries the cleanest inventory of SR motors we have seen yet.

Marco provided us with a very clean S13 blacktop engine along with all the parts necessary to complete the swap. We recommend buying a complete engine swap, which includes the transmission, igniter chip, ECU, MAF sensor, intake elbow, and wire harness. Unless you suffer from some kind of migraine fetish, do not buy just the engine and transmission from some scam artist on E-bay.

Before purchasing any SR engine, there are a few key areas that should always be inspected. First, remove the oil cap and inspect the #1 cam lobe with a flashlight for any scoring (Remove the entire valve cover if you can). The needle-sized ports on the SR’s oil delivery tube are prone to clogging over the number one cam lobes and can quickly cause engine failure.

Secondly, a common problem with an engine that has traveled halfway around the world sitting on its oil pan is exactly that, the oil pan. The SR20DET is particularly picky about having a dent free oil pan, as a few dents in the right places will block the oil pick up tube and starve the engine of oil. This of course, will lead to premature, if not immediate, engine failure upon start up. We were fortunate in that our oil pan had no serious dents, but decided to be safe and bang out the small dents that were there. Once the oil pan’s bolts are removed, we used a thin piece of sheet metal to slice through the RTV and remove the oil pan. Do not use a screwdriver to pry off the oil pan, as it will mangle its flange. With the pan removed unscathed, we banged out the small dents with a hammer. Before installing the oil pan, make sure to scrape off all the old RTV before applying more and putting the pan back in place.

Lastly, remove the spark plugs and inspect them thoroughly for signs of foul play. A normal plug will be a tan color with white speckles. Spark plugs are often considered an “eye” into the engine and can provide valuable insight into an engine’s past life. For example, an oily spark plug can be evidence of failed piston ring.

Along with our engine, we also picked up a Silvia radiator, fans, and shroud. Although these are not necessary and the USDM radiator can be used, we opted for the JDM unit since it would produce a cleaner appearance in the engine bay. The top radiator hose on the USDM unit is located opposite of its JDM counterpart and requires some rerouting of the hoses from one side of the engine compartment to the other.

While the engine had been cleaned very thoroughly and looked new on the outside, its past life in Japan will forever remain a mystery. Due to this fact being true on most imported engines, it is always a good idea to change the clutch while the motor is out of the car and the transmission is easily accessible.

For our clutch, we contacted Jason Garrett Young, owner of JGY Customs. JGY Customs is one of the few shops in the U.S. that specializes strictly in Nissan performance, stocking a full array of OEM and aftermarket components, and also having completed numerous SR20DET swaps. Jason recommended an ACT clutch kit (#NM1-HDSS) for our application. The ACT clutch consists of a Heavy Duty Pressure Plate with a modified street disc. This kit is meant for a 1984-2001 Nissan Maxima, but is also applicable for use in the RWD SR20DET. Its torque capacity of 362 ft-lbs should be more than enough to handle our SR20DET on stock boost and any future upgrades.

Before installing the clutch, the flywheel was taken to a local shop to get resurfaced. When installing the clutch, make sure the flywheel is free of dirt or oily finger prints. We used Simple Green to degrease the surface of the flywheel. After everything was nice and clean, the flywheel, clutch disc and pressure plate were assembled. Be sure to use the alignment tool to center the clutch on the flywheel so the bellhousing can be reattached to the engine. After a few minutes of frustration and wrestling, the transmission reunited with the engine encasing a tougher clutch with a bit more holding capacity.

Heater Hoses

Before installing the motor into the car, it is important to re-orient the hoses on the rear of the engine since they will be impossible to reach once the motor is installed.

The first hose that needs to be altered is a metal line, which is bolted directly to the motor. This line can be removed since the hose connected to it will no longer point in the same direction.

After removing the hard section of line, bolt the turbo coolant line bracket back into the block (you may need to gently bend this line slightly).

Find a suitable piece of hose, trim to fit and reconnect the line.

Take the two heater lines and turn them so they face towards the passenger side of the car.

In order to extend these hoses, we purchased two brass ¾” - 3/8” brass reducer couplings and a heater hose with a 90 degree bend. You will need connectors as the Japanese hoses and American heater core nipples are different diameters.

After re-routing the appropriate hoses, the heat shield from the turbine housing will need to be removed in order to clear the steering column. Also for our swap, we decided to remove the AIV pipe and plugged the opening in the down pipe using Nissan part number 14052-21R00.

Lastly, before installing the engine, we decided to perform a mock fitting of the wiring harness, matching each plug with its respective sensor on the engine. Once we located each sensor, we labeled the plugs with numbers for easy identification later. This step will prevent you from having to hunt for missing connections after the engine is in the car. If this is your first time performing an SR swap, this step will help familiarize you with a seemingly rat nest-like mess of wires.

With the preparation complete, the fierce turbocharged SR20DET is now prepped to free our Project 240SR from the miserable performance of the old motor. In our next update we will cover the installation of the new powerhouse into Project 240SR. Stay tuned.

Ain't this the pretiest motor or what?

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