Reinforced valve spring kit Toyota 4A-GE 16V

€659.53 (tax incl.)

Reinforced valve spring kits for the Toyota 4A-GE 16V (Corolla, Celica, Sprinter, Carina, Conquest).

Brand: SUPERTECH
Engines: 4A-GE 1.6 16V (Corolla AE86 and AE92, Celica, Sprinter, Carina V, Conquest)
Springs: single or double
Contents: springs, upper retainers, lower spring seats, stem seals or guides depending on the kit

Toyota 4A-GE 16V engine covered

The 4A-GE is the 1.6 litre four-cylinder with 16 valves and twin overhead camshafts found in the Corolla AE86 and AE92, the Celica AA63, the Sprinter GTi, the Carina V and the Conquest RSi. Its tappets are mechanical, adjusted with shims.

The kit replaces the original spring with its upper retainer and lower spring seat; only the factory collets stay in place.

SUPERTECH reinforced valve spring kit

After each lift, a 4A-GE valve must settle onto its seat at once. A weak spring lets it bounce, now and then onto the piston: valve float, a fault that worsens as revs climb.

Seat pressure: 245 N at 35.4 mm for the SPRK-TC25S (single spring), 325 N at 35.4 mm for the SPRK-TC25D and the SPRK-TC25D-2 (double springs).

Valve spring kit technical specification

Part number	Brand	Springs	Outer / inner Ø	Seat pressure	Max lift	Kit contents
SPRK-TC25S	SUPERTECH	Single	Outer 25.0 mm Inner 18.0 mm	245 N at 35.4 mm	14.4 mm	Springs, upper retainers, lower spring seats
SPRK-TC25D	SUPERTECH	Double	Outer 25.0 / 18.0 mm Inner 18.0 / 13.0 mm	325 N at 35.4 mm	14.4 mm	Springs, upper retainers, lower spring seats, stem seals
SPRK-TC25D-2	SUPERTECH	Double	Outer 25.0 / 18.0 mm Inner 18.0 / 13.0 mm	325 N at 35.4 mm	14.4 mm	Springs, upper retainers, lower spring seats, stem seals, guides

Valve spring kit fitting details

Part	Toyota original	Reinforced spring kit
Spring	90501-33001	Kit specific: SPR-TC25S or SPR-TC25D
Retainer	13741-16010	Kit specific: RET-2500/T1
Spring seat	13734-16010	Kit specific: SS-3012
Collets	90913-03021	Original kept

The three SUPERTECH kits all bring RET-2500/T1 upper retainers and SS-3012 lower spring seats, with either an SPR-TC25S spring (single) or an SPR-TC25D spring (double). The SPRK-TC25D adds VS-T6SM valve stem seals, and the SPRK-TC25D-2 adds GDE-T4AG-SM guides on top; the original collets are kept.

Valve closed, the gap that separates the two spring supports is known as the installed height. Each load in the table exists only at that exact figure; machining the head face lengthens it, and force then drops in proportion to spring rate. The three kits are listed just below, all set at 35.4 mm, each with its own seat load.

	SUPERTECH
Installed height	35.4 / 35.4 / 35.4 mm
Seat pressure at this height	245 / 325 / 325 N

Technical guide

Our brands

SUPERTECH is based in California and has made competition cylinder head components for over thirty years. Each batch of springs shipped has been through laser scanning, ultrasonic testing and X-rays before leaving the factory, so that no hidden internal anomaly remains.

How to choose

Whenever the engine revs higher or opens its valves further than it did originally, only added load keeps valve and cam in contact. The three kits deliver 245 N for the single spring and 325 N for the doubles, at the heights given above. Do not chase maximum load by reflex: an overly powerful spring gnaws at cams and mechanical tappets. As for lift, the cam must not exceed the 14.4 mm that the kits accept at most.

Criterion	Key point
Choosing the pressure	Fifty-five or seventy-three pounds: that number designates the seat pressure, which the table also gives in newtons. Three things guide the choice, namely camshaft lift, the top revs envisaged and any turbo added; the harder you ask, the heavier the spring must be. Too little load lets the valve float, too much tires the valvetrain needlessly.
Single or double spring	As for springs, the SPRK-TC25S has just one per valve, hence a firmness close to the original; two nested springs for the SPRK-TC25D and the SPRK-TC25D-2, markedly firmer. The SPRK-TC25D-2 is singled out by its GDE-T4AG-SM guides, supplied in the kit and intended for the VS-T6SM stem seals.

When reinforced springs become necessary

Higher-lift cam than the stock one
Limiter raised for higher revs
Turbo or supercharger on the 4A-GE
Head rebuilt for track, rally or drift
Tired springs: valves floating ahead of the limiter

Compatible vehicles

Model	Engine code	Power	Years
Corolla GT 16V, GTi Twin Cam (AE86)	4A-GE	124-131 hp	1983-1987
Sprinter GTi (AE82)	4A-GE	131 hp	1983-1987
Celica (AA63)	4A-GE	124 hp	1983-1985
Corolla (AE92)	4A-GE	116 hp	1987-1994
Corolla Liftback GTi (AE92)	4A-GE	125 hp	1987-1993
Corolla Compact GTi (AE92, AE93)	4A-GE	116 hp	1987-1994
Corolla Levin (AE92)	4A-GE	140 hp	1989-1991
Carina V (AT171)	4A-GE	120-140 hp	1988-1992
Conquest RSi (E90)	4A-GE	121 hp	1988-1993