Reinforced valve spring kit Toyota 2UZ-FE 3UZ-FE
Reinforced kit of 32 valve springs for the Toyota 2UZ-FE and 3UZ-FE V8 engines.
- Brand: SUPERTECH
- Engines: 2UZ-FE 4.7 V8 32V, 3UZ-FE 4.3 V8 32V
- Springs: single
- Contents: springs, upper retainers
Toyota 2UZ-FE and 3UZ-FE engines covered
This kit is aimed at Toyota's 32-valve V8s: the 4.7 litre 2UZ-FE, found under the Land Cruiser 100 and 200, 4Runner, Sequoia and Tundra, and the 4.3 litre 3UZ-FE, fitted to the Aristo, Celsior, Crown and Soarer.
The original springs carry the Toyota references 90501-29059 and 90501-29043. The kit replaces the springs and the upper retainers; the original lower spring seats and collets stay in place.
SUPERTECH reinforced valve spring kit
Once the lobe has passed, it falls to the spring to close the valve and seat it again. Where load is lacking at high engine speed, the valve rebounds, closes behind time and can hit the piston crown: this is valve float. More spring load keeps that danger away on all 32 valves of this V8.
Seat pressure: 356 N at 35 mm (single springs).
Valve spring kit technical specification
| Part number | Brand | Springs | Outer / inner Ø | Seat pressure | Open pressure | Rate | Max lift | Kit contents |
|---|---|---|---|---|---|---|---|---|
| SPRK-TU24 | SUPERTECH | Single | 356 N at 35 mm | 32 springs, 32 upper retainers |
Valve spring kit fitting details
| Part | Toyota original | Reinforced spring kit |
|---|---|---|
| Spring | 90501-29059 / 90501-29043 | Kit specific: SPR-TU24 (single) |
| Retainer | 13741-50030 | Kit specific: RET-TU24/T1 |
| Spring seat | 13734-62020 | Original kept |
| Collets | 90913-03028 | Original kept |
The SUPERTECH kit contains 32 single SPR-TU24 springs and 32 RET-TU24/T1 upper retainers. The original lower spring seats and collets are kept.
Assembly height is the length of the spring fitted between its lower seat and its upper retainer with the valve shut. The stated seat pressure applies at that length only. Should it increase, say after seat re-cutting or head skimming, pressure drops in proportion to the spring rate. The kit's figures, gathered below, are quoted for that length.
| SUPERTECH | |
|---|---|
| Installed height | 35 mm |
| Seat pressure at this height | 356 N |
Technical guide
Our brands
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SUPERTECH is a company based in California for over thirty years, serving competition engine builders. Chrome-silicon-vanadium alloy wire is what its springs are coiled from, and every batch is inspected using ultrasound, X-rays and a laser before dispatch. |
How to choose
Firmer springs keep the valve held against the cam at engine speeds where factory springs give up: the limiter can go up, and a sharper camshaft or a blower becomes workable without float. The kit provides 356 N at the seat for a 35 mm height, the figure repeated in the height table. A single restriction applies: cam lift must remain below what the kit tolerates, a value SUPERTECH does not release, so consult us before adopting a very aggressive profile.
| Criterion | Key point |
|---|---|
| Choosing the pressure | On this kit the seat load is expressed in pounds (80 lbs), which is 356 N for a spring compressed to 35 mm. Three factors settle the question: how high the lobes lift, how fast the engine is meant to turn, and how much boost it sees; each demands more from the spring. More load does not always mean more gain: lobes, tappets and shims wear faster for no benefit. |
| Single or double spring | The springs in this kit are single, made from one wire, hence nearer to the original fitting than a double-spring setup. It comprises 32 springs and 32 upper retainers, meaning both heads of the V8; the factory lower seats and collets are kept. |
When reinforced springs become necessary
- Camshafts livelier than the original ones
- Revs you wish to push up
- Supercharger or turbo added to this V8
- Heads refreshed for sporting off-road or circuit use
- Tired springs: the valves float before the limiter
Compatible vehicles
| Model | Engine code | Power | Years |
|---|---|---|---|
| Land Cruiser 100 4.7 (UZJ100) | 2UZ-FE | 233-238 hp | 1998-2007 |
| Land Cruiser 200 4.7 V8 (UZJ200) | 2UZ-FE | 271-315 hp | 2007- |
| 4Runner IV 4.7 (UZN210 / UZN215) | 2UZ-FE | 238-273 hp | 2002-2009 |
| Sequoia 4.7 (UCK35 / UCK45) | 2UZ-FE | 238-280 hp | 2000-2007 |
| Sequoia 4.7 (UCK60 / UCK65) | 2UZ-FE | 280 hp | 2007-2014 |
| Tundra 4.7 (UCK30 / UCK40) | 2UZ-FE | 249-282 hp | 1999-2006 |
| Tundra 4.7 (UCK50-UCK57) | 2UZ-FE | 280 hp | 2006-2009 |
| Aristo 4.3 (UZS161) | 3UZ-FE | 305 hp | 1999-2004 |
| Celsior 4.3 VVTi (UCF30 / UCF31) | 3UZ-FE | 283 hp | 2000-2006 |
| Crown 4.3 (UZS181-UZS187) | 3UZ-FE | 280 hp | 2003-2008 |
| Crown 4.3 V8 4WD (UZS200) | 3UZ-FE | 280 hp | 2009-2012 |
| Soarer 4.3 VVTi (UZZ40) | 3UZ-FE | 283 hp | 2000-2005 |
OEM part number (valve spring): 90501-29059 / 90501-29043
Related products
Heads already off? Might as well have valves and guides checked, so the engine stays closed later. Pages available now for these engines:
| Toyota 2UZ-FE 3UZ-FE inlet valves → |
| Toyota 2UZ-FE 3UZ-FE exhaust valves → |
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Brand
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ReferenceSPRK-TU24
