Reinforced valve spring kit Toyota 1ZZ-FE 2AZ-FE

Toyota 1ZZ-FE and 2AZ-FE engines covered

This kit covers two Toyota four-cylinder engines with 16 valves, twin overhead camshafts and VVT-i variable timing: the 1.8 litre 1ZZ-FE and the 2.4 litre 2AZ-FE. Their valves are driven by solid tappets. They sit under the bonnet of the Corolla, Avensis, Celica, MR2, Camry, RAV4, Previa and Alphard, among others.

The kit replaces the standard spring, its upper retainer and its lower spring seat; the original collets are kept.

SUPERTECH reinforced valve spring kit

Beyond the cam lobe's peak, the spring has to call the valve back to its seat and keep it shut. When revs climb, the valve lags behind: with too weak a spring it rebounds, shuts late, then risks striking the piston. This behaviour is called valve float.

Single spring kit: 267 N at 34 mm (60 lbs). Double spring kit: 360 N at 34 mm (81 lbs).

Valve spring kit technical specification

Valve spring kit fitting details

Both SUPERTECH kits contain 16 springs, 16 upper retainers and 16 SEAT-TS/TC lower spring seats. The first pairs single SPR-TS10115-SI springs with RET-TS55/TC-S retainers, the second double SPR-TS1015 springs with RET-TS55/TC retainers; the original collets stay fitted.

Measure installed height with the valve closed, from the lower spring seat where the spring rests up to the upper retainer. A quoted load holds only at this figure, 34 mm for both kits. Should it grow, for instance once the head face is machined, the load drops by one spring rate per extra millimetre. The table below sets both heights and both loads side by side.

Technical guide

Our brands

SUPERTECH is a Californian company supplying valvetrain parts to competition teams, with a long record of more than thirty years. Springs leave the plant only after ultrasound, X-ray and laser passes, so a hidden internal flaw cannot slip into a delivery.

How to choose

More force on the spring and the valve follows the cam faithfully instead of lifting away from it: the limiter can climb, the camshaft can turn sharper, a turbo can join in without the valves floating. The two kits give 267 N and 360 N on the seat at 34 mm, the figures in the previous table. One safeguard only: your camshaft lift has to remain under the kit's maximum lift, 13.3 or 13.8 mm depending on the reference.

When reinforced springs become necessary

• Camshaft lifting higher than standard
• Peak rpm you wish to raise
• Turbo added to a naturally aspirated engine
• Head rebuilt for circuit or rally
• Tired springs or valve float below the limiter

Compatible vehicles

OEM part number (valve spring): 90501-30022 ; 90501-29048 ; 90905-01084 ; 90501-27029 ; 90080-50253 ; 90080-50248 ; 90501-28038 ; 90905-01066 ; 90905-01065 ; 90080-50254

Related products

Head removed? Have the valves and guides inspected right now, inlet and exhaust alike. The two buttons below go to the 1ZZ-FE valves: