Reinforced valve spring kit Honda Civic X L15B7
Kit of 16 reinforced valve springs for the Honda 1.5 turbo L15B7 engine of the Civic X.
- Brand: FERREA
- Engine: L15B7 (Civic X 1.5 turbo)
- Springs: single
- Contents: springs, titanium upper retainers, lower spring seats, collets
The Honda engine covered
This kit is for the L15B7, the 1.5 litre direct-injection turbo four-cylinder with 16 valves and variable timing used in the Civic X. It makes 170 to 205 hp depending on the version (VTEC Turbo, RS, Si).
For this engine FERREA supplies its own spring, titanium upper retainers, lower spring seats and collets, with separate retainers and seats for inlet and exhaust.
FERREA reinforced valve spring kit
Past the cam peak, the spring puts the valve back on its seat. At high revs the valve bounces, leaves the cam and risks striking the piston, known as valve float.
The kit gathers 16 single springs, one coil each, 21.4 mm outer and 15.0 mm inner diameter. Its titanium retainers are 40% lighter than a steel one, according to FERREA.
Valve spring kit technical specification
| Part number | Brand | Springs | Outer / inner Ø | Seat pressure | Open pressure | Rate | Max lift | Kit contents |
|---|---|---|---|---|---|---|---|---|
| KT4051 | FERREA | Single | Outer 21.4 mm Inner 15.0 mm |
16 springs, 16 titanium upper retainers, 16 lower spring seats, 16 collets |
Valve spring kit fitting details
| Part | Honda original | Reinforced spring kit |
|---|---|---|
| Spring | Kit specific: S10182 (single) | |
| Retainer | Kit specific: E11151 (inlet), E11150 (exhaust), titanium | |
| Spring seat | Kit specific: SL1182 (inlet), SL1181 (exhaust) | |
| Collets | Kit specific: K10116 |
The FERREA KT4051 kit contains 16 S10182 single springs, 8 E11151 titanium upper retainers for the inlet and 8 E11150 for the exhaust, 8 SL1182 lower spring seats for the inlet and 8 SL1181 for the exhaust, plus 16 K10116 collets.
Installed height is taken with the valve closed, from the lower spring seat up to the upper retainer. The higher the spring is fitted, the lower its seat load, by the value of its rate for each millimetre added. Measure it on every valve: it varies from one valve to the next with the machining of the seats and the head, and is checked before the engine is closed.
| FERREA | |
|---|---|
| Installed height | |
| Seat pressure at this height |
Technical guide
Our brands
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FERREA began in Florida in 1978, set up by Argentine engine builders who had moved to the United States. The company machines its own valves, springs, retainers and tappets, used in NASCAR as well as in drag racing and circuit single-seaters. |
How to choose
A firmer spring postpones valve float, which allows higher revs, a sharper camshaft or more turbo pressure. The KT4051 is a single spring, with its titanium retainers. Before buying, check the lift of your camshaft and the boost you are aiming for: on a remapped L15B7 it is the boost that loads the springs most. These figures are found on the camshaft or tuning sheet; the check takes a few minutes and avoids an ill-suited purchase.
| Criterion | Key point |
|---|---|
| Choosing the pressure | The load you need depends on three things: camshaft lift, target revs and turbo pressure. If one rises, the load must follow. A spring harder than necessary brings nothing: it tires cams and tappets and loads the whole valve train more. This kit offers a single configuration, so there is no load to choose. |
| Single or double spring | The single spring has just one coil, where a dual spring stacks two. The titanium upper retainers, the lower spring seats and the collets come with the kit, one pair of seats for the inlet and one for the exhaust, so these parts do not have to be sourced separately. |
When reinforced springs become necessary
- Camshaft with more lift than the standard one
- Maximum revs pushed beyond the factory figure
- Remap or larger turbo, raised pressure
- Head rebuilt for circuit or hill climb
- Tired original springs, valves that float
Compatible vehicles
| Model | Engine code | Power | Years |
|---|---|---|---|
| Civic X 1.5 VTEC (FK7) | L15B7 | 170 hp | 2017- |
| Civic X 1.5 VTEC (FK7) | L15B7 | 173 hp | 2017- |
| Civic X 1.5 VTEC (FK7) | L15B7 | 177 hp | 2016-2021 |
| Civic X 1.5 VTEC (FK7) | L15B7 | 182 hp | 2017-2022 |
| Civic X 1.5 (FC1) | L15B7 | 170 hp | 2016- |
| Civic X 1.5 (FC1) | L15B7 | 177 hp | 2015-2021 |
| Civic X 1.5 VTEC (FC1) | L15B7 | 182 hp | 2016-2022 |
| Civic X 1.5 RS Turbo (FC1) | L15B7 | 173 hp | 2016-2022 |
| Civic X 1.5 Si (FC1) | L15B7 | 205 hp | 2017-2020 |
| Civic X Coupé 1.5 | L15B7 | 170 hp | 2016- |
| Civic X Coupé 1.5 | L15B7 | 177 hp | 2016- |
| Civic X Coupé 1.5 Si (FC1) | L15B7 | 205 hp | 2017- |
Related products
Head off the engine? Have valves and guides checked before fitting the new springs. The matching inlet and exhaust valves are offered below:
| HONDA Civic X L15B7 inlet valves → |
| HONDA Civic X L15B7 exhaust valves → |
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Brand
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ReferenceKT4051
