Reinforced valve spring kits for the Nissan SR20DE and SR20DET 2.0 16V engines.
These kits are made for the SR20DE and SR20DET, 2.0 litre four-cylinder engines with twin camshafts and 16 valves, naturally aspirated or turbocharged, fitted to the 100NX, the Sunny GTI and GTi-R, the Primera, the Almera, the Serena, the 200SX and the Silvia.
Originally each valve is closed by a single spring, 13203-53J00, topped by an upper retainer 13209-53J00 and resting on the lower spring seat 13205-53J00; collets 13210-D4200 lock the assembly.
The spring closes the valve once the cam has passed and keeps it pressed against it. At high rpm the valve's inertia beats a spring that is too soft: it bounces, closes late and may strike the piston. A firmer spring removes that fault.
The five kits quote seat loads from 302 N to 516 N at an installed height of 40.5 mm.
| Part number | Brand | Springs | Outer / inner Ø | Seat pressure | Open pressure | Rate | Max lift | Kit contents |
|---|---|---|---|---|---|---|---|---|
| SPRK-H1021S-SR20 | SUPERTECH | Single | Outer 30.0 / 21.8 mm | 302 N at 40.5 mm | 712 N at 10 mm | 41.4 N/mm | 15.0 mm | Springs, titanium upper retainers |
| SPRK-H1020S-SR20 | SUPERTECH | Single | 334 N at 40.5 mm | Springs, titanium upper retainers | ||||
| SPRK-H1022D-SR20 | SUPERTECH | Double | Outer 30.0 / 21.8 mm Inner 20.5 / 15.5 mm |
400 N at 40.5 mm | 899 N at 10 mm | 49.8 N/mm | 16.0 mm | Springs, titanium upper retainers, lower spring seats |
| SPRK-H1021D-SR20 | SUPERTECH | Double | Outer 30.0 / 21.8 mm Inner 21.3 / 15.5 mm |
472 N at 40.5 mm | Springs, titanium upper retainers, lower spring seats | |||
| SPRK-H1020D-SR20 | SUPERTECH | Double | 516 N at 40.5 mm | Springs, titanium upper retainers, lower spring seats |
| Part | Nissan original | Reinforced spring kit |
|---|---|---|
| Spring | 13203-53J00 | Kit specific: SPR-H1021S/SR and SPR-H1020S (single); SPR-H1022D, SPR-H1021D and SPR-H1020D (double) |
| Retainer | 13209-53J00 | Kit specific: RET-NSR20/T1 (titanium) |
| Spring seat | 13205-53J00 | Double kits: kit specific (SEAT-SR20/6; SEAT-H/N240 on the SR20DET exhaust). Single kits: original kept |
| Collets | 13210-D4200 | Original kept |
Each SUPERTECH kit contains the springs and titanium upper retainers; the double kits add lower spring seats, the single kits keep the original ones, and the original collets stay in place.
Measured with the valve closed, installed height runs from the lower spring seat, which carries the foot of the spring, up to the upper retainer capping its head. All five kits are quoted at 40.5 mm. If that figure grows, after the seat faces have been skimmed for example, the load drops further the stiffer the spring is; the neighbouring table repeats the reference.
| SUPERTECH | |
|---|---|
| Installed height | 40.5 mm |
| Seat pressure at this height | 302 / 334 / 400 / 472 / 516 N |
 |
SUPERTECH is a Californian company born in motorsport; tuners have relied on its valvetrain parts for more than thirty years. The springs are coiled from chrome, silicon and vanadium alloy steel, and each batch is checked with ultrasound, then X-rays, then a laser. |
Firmer springs hold the valve on the cam profile much higher in the rev range: you can push back the red line, fit a hotter camshaft or raise turbo pressure on the SR20DET without the bounce coming back. The single kits suit a lightly modified engine; the double kits are aimed at more serious builds. Whatever the cam lifts the valve must stay lower than the maximum lift quoted for the chosen kit, when one is published.
| Criterion | Key point |
|---|---|
| Choosing the pressure | The pounds (lbs) in the original name give the seat pressure: 68 lbs is 302 N, 116 lbs is 516 N. To decide, weigh camshaft lift, target rpm and boost: the higher they go, the more load is needed. A load above what you need serves no purpose and wears the cams faster; start from how the engine will really be used. |
| Single or double spring | The single spring, more compact, leaves the original lower spring seats in place. The double spring fits a second spring inside the first, so the effort is split between them and their vibrations die away faster, which suits hard-driven or boosted engines. The upper retainers are titanium in every kit. |
| Model | Engine code | Power | Years |
|---|---|---|---|
| 100NX 2.0 GTI (B13) | SR20DE | 1990-1994 | |
| Sunny III 2.0 GTI 16V (N14) | SR20DE | 1990-1995 | |
| Sunny III 2.0 GTi-R 4x4 (N14) | SR20DET | 1990-1995 | |
| Primera 2.0 (P10) | SR20DE | 1990-1996 | |
| Primera Estate 2.0 (W10) | SR20DE | 1994-1998 | |
| Primera 2.0 16V (P11) | SR20DE | 1996-2002 | |
| Almera I 2.0 GTi (N15) | SR20DE | 1996-2000 | |
| Serena 2.0 (C23) | SR20DE | 1992-2001 | |
| 200SX 2.0 Turbo (S14) | SR20DET | 1993-2000 | |
| 200SX Turbo (S15) | SR20DET | 2000-2002 | |
| Silvia Turbo (S15) | SR20DET | 1999-2003 |
OEM part number (valve spring): 13203-53J00
Cylinder head off? Take the chance to have the valves, their guides and stem seals checked too. Here is what we offer for this engine:
| SR20DE SR20DET inlet valves → |
| SR20DE exhaust valves → |
