What Exactly Is The SR20DET Engine?
The SR20DET was birthed from the need for Nissan to develop a high-performance engine to meet impending emissions standards while providing adequate power at a lower production cost. The former CA18DET engines were considered too expensive (because of their cast iron block), and since they couldn’t meet the Japanese emission standards, the SR20DET replaced them.
Like similar Nissan engines, the SR20DET engine name included the basic breakdown of the engine. The “SR” initials refer to the engine family. “20” indicates the displacement (2.0), “D” means dual overhead cam, “E” stands for electronic fuel injection, and “T” is for the fact that the engine is turbocharged.
Initially, the engine was developed as a transverse turbocharged engine used in the ‘89 Nissan Bluebird 2000SSS and the ‘90 Pulsar GTI-R for the Japanese market. In 1991, the engine was placed longitudinally in the rear-wheel drive S13 Silvia and 180SX.
By the middle of the decade, the engine was used in various Nissan vehicles as a naturally aspirated and turbocharged motor. The engine was produced for thirteen years until 2002. Still, Nissan never exported the turbo-charged version to the United States, preferring to use the naturally aspirated version of the SR20DE in Sentras, Pulsars, and Infiniti G20.
The SR20DET engine comprises a closed deck, an aluminum block, an aluminum cylinder head, alloy cylinder liners, and hydraulic valve lifters. With a square bore of 3.39 inches (86 mm) and a stroke of 3.39 inches (86 mm), the SR20DET produced 201-247 hp and 196-205 lb-ft during its 13-year production cycle. Most SR20DET engines operate with compression ratios of 8.5:1.
The engine features a dual overhead cam system powering 16 valves. Early versions of the S13 SR20 had “high-port” cylinder heads with non-variable timing camshafts. While the Garrett T25G supercharger worked its forced induction magic, the 370 cc high-impedance fuel injectors ensured a proper flow into each combustion chamber. They are identified by the red or black valve covers (also known as flattops).
In 1991, Nissan introduced a newly designed S14 SR20 engine with VCT (variable cam timing), a “Low-Port” new cylinder head, an enlarged T28G turbocharger, and a revamped intake manifold. Smaller ports increased intake velocity, which helped produce better power outputs (220 hp). These black covers are called “Notch Tops” or “Slant-Top” and can be recognized by their unique valve cover.
Again, in 1999, the S15 SR20 saw further upgrades to ball-bearing journals in the T28GR turbo and more capable 480 cc fuel injectors. A new, improved engine management system boosted power levels even more (250 hp), trading the old external igniters for a more efficient coil-on-plug system. These black tops were used in ‘99 - ‘02 S15 Silvia.
Nissan used the SR20DET “silver top” in the ‘97 - ‘01 Avenir station wagon, incorporating a Garrett T28BB turbocharged and producing a tepid 227 hp.
What Are the Specs Of The SR20DET?
How Reiliable Was The SR20DET?
The SR20DET is a capable powerplant with strong engine internals, especially when it is well-maintained. The engine's integrity seems evident since Nissan used the motor for over a decade in most of their models. Performance junkies view it as a favorite for aftermarket upgrades and engine swaps, often replacing the heavier cast iron CA18DEs with one of the SR variants.
Without a doubt, Nissan overengineered the engine, keeping the power capacities down under maximum limits, which makes these motors capable of handling significant upgrades. The aluminum SR Series engines provide an excellent weight balance for circuit racing or drifting applications or owners who desire a high-peak power output for drag racing.
Even though modifying an SR20DET to produce more output is relatively simple, finding an engine that hasn’t exhausted itself in a past life is next to impossible. These Japanese engines were often pushed to their limits during their lifetimes. In these cases, most have likely had very spotty maintenance routines (which only further affects the internals). Any owner of an SR20DET should take pains to review previous maintenance schedules before laying down hard-earned money for a used engine. In addition, any issues that might arise should be addressed immediately to prevent further damage to internal components.
What Are The Issues That The SR20DET Is Known For?
If you plan to upgrade your SR20DET engine (particularly as an engine swap), some things about the motor can complicate matters. Let’s look at the more common issues associated with the SR20DET.
Nissan designed the oil pan on the SR20DET to be located on the base of the engine (it is relatively small), and to ensure adequate lubrication, the oil pickup was set just a few millimeters from the base of the oil pan. This means that if you bottom out the car or scrape the oil pan on a speed bump, you can damage the oil pickup tube and the oil strainer inside. (We are talking about early SR models because Nissan redesigned the strainer for the S14 model but didn’t increase the size or location of the pan).
The oil pickup rod can crack, or the strainer gets pushed to the bottom of the pan and fails to squirt oil into your engine. No oil means no lubrication for your motor, which can cause engine lockup. Many owners who notice damage to the oil pan simply drop the pan, bang out the dent, or replace the pan without examining the strainer or the brackets for the oil feeders. Use caution if you notice any cracks or if the oil strainer somehow seems damaged. Replace them so that you are not sitting on a ticking time bomb.
Bad Rod Bearings
One of the things that happens when any engine runs out of oil is that the engine suffers from extreme heat issues. Internal components, like rod bearings, can seize up as the heat fuses them. If you notice the temp of your engine rising or the oil pressure sensor triggering a warning light, pull the car over and kill the engine.
If you hear a loud knocking coming from your engine, the rod bearings are likely bad and have possibly caused damage to the crankshaft. When this happens, technicians will drop the oil pan looking for evidence of metal shavings, another telltale sign of metal bearings beating against other metal components. Upon inspection, you should consider a complete overhaul if you find extensive damage, scarring, or scratches on the crankshaft. Many enthusiasts will opt for a crate engine since a complete rebuild will cost as much, considering the time and labor involved.
SR20DET engines are known for throwing rocker arms, which can sometimes cause timing problems and bent valves. The most common symptom of a lousy rocker is a clicking or ticking noise from the engine. Rocker arms are relatively easy to replace, and if you are upgrading a camshaft, consider replacing them or using rocker arm stoppers to keep them in place.