Reinforced valve spring kit Honda D16A6
Reinforced single valve spring kit for the Honda D16A6 1.6 16V engine.
- Brand: SUPERTECH
- Engine: D16A6
- Springs: single
- Contents: springs, upper retainers, lower exhaust spring seats
Honda engine covered
This kit is made for the D16A6, a 1.6 litre 16-valve single-cam engine fitted to the Civic IV (ED, EE), the Civic Shuttle 4WD and the CRX II 1.6 Si between 1987 and 1991.
Each single spring in the kit takes the place of the standard part. Lower spring seats change on the exhaust side only; the inlet seats and the collets stay as original.
SUPERTECH reinforced valve spring kit
Once the lobe has gone by, the spring is what returns the valve to its seat. At speed, the valve's mass wants to keep travelling: lacking load, it bounces, shuts late and can hit the piston. That is valve float.
This kit gives 325 N on the seat at 40.6 mm installed, then 854 N after 12 mm of lift.
Valve spring kit technical specification
| Part number | Brand | Springs | Outer / inner Ø | Seat pressure | Open pressure | Rate | Max lift | Kit contents |
|---|---|---|---|---|---|---|---|---|
| SPRK-H1003S | SUPERTECH | Single | Outer 23.7 mm Inner 16.3 mm |
325 N at 40.6 mm | 854 N at 12 mm | 44.0 N/mm | 13.3 mm | Springs, upper retainers, 8 lower exhaust spring seats |
Valve spring kit fitting details
| Part | Honda original | Reinforced spring kit |
|---|---|---|
| Spring | Kit specific (single) | |
| Retainer | Kit specific | |
| Spring seat | Kit specific (exhaust) | |
| Collets | Original kept |
The SUPERTECH kit includes the single springs, the upper retainers and eight lower spring seats meant for the exhaust side. On the inlet side the original lower seat is reused, as are the collets.
Installed height is taken with the valve closed: it is the free space between the lower seat's bearing face and the underside of the upper retainer. With this kit, 325 N is obtained at exactly 40.6 mm, spring compressed between its two seats. If the figure increases, every extra millimetre takes the spring rate away from the load; the reference height is repeated below.
| SUPERTECH | |
|---|---|
| Installed height | 40.6 mm |
| Seat pressure at this height | 325 N |
Technical guide
Our brands
 |
SUPERTECH was born in California and has worked on cylinder head parts for motorsport for over thirty years. Its springs use alloy wire of chrome, silicon and vanadium steel, and every production batch is put through ultrasound, radiography and laser measurement before it ships. |
How to choose
A firmer spring tracks the cam profile through more revs: redline pushed up, a livelier camshaft or even a turbo, without float coming back. Here the kit gives 325 N on the seat at 40.6 mm. Beyond 13.3 mm of net lift it has no travel reserve left, so the camshaft chosen must stay under that figure. Sustained driving also gains in consistency, since the engine stays healthy through long sessions, and valve behaviour is easier to check on the bench.
| Criterion | Key point |
|---|---|
| Choosing the pressure | The 73 lbs mention corresponds to 325 N on the seat. To choose, weigh cam lift, the revs you want and any forced induction against one another; if one of these goes up, load should rise with it, without exceeding what the kit allows. Too much load brings nothing good: the camshaft wears faster, and the whole valvetrain is stressed for no reason. |
| Single or double spring | A single spring sits on every valve, 23.7 mm in outer diameter. The assembly therefore stays near stock and the build keeps its original principle. Upper retainers are supplied with the springs, while the collets are the car's own. |
When reinforced springs become necessary
- Camshaft lifting higher than the original
- Redline moved up significantly
- Turbo added or boost pressure increased
- Head rebuilt for rallying or circuit work
- Tired springs, or float noticed near the redline
Compatible vehicles
| Model | Engine code | Power | Years |
|---|---|---|---|
| Civic IV 1.6 i 16V (ED4) | D16A6 | 109 hp | 1987-1991 |
| Civic IV 1.6 i 16V (ED7) | D16A6 | 109 hp | 1987-1991 |
| Civic IV Shuttle 1.6 i 16V 4WD (EE4) | D16A6 | 109 hp | 1988-1989 |
| Civic IV 1.6 i 16V 4x4 (EE5) | D16A6 | 109 hp | 1989-1991 |
| CRX II 1.6 Si | D16A6 | 110 hp | 1988-1991 |
Related products
Cylinder head off? Time to inspect valves and guides before closing up. The matching parts for the D16A6 are behind the two buttons below:
| Honda D16A6 inlet valves → |
| Honda Civic CRX D16A6 exhaust valves → |
-
Brand
-
ReferenceSPRK-H1003S
