Reinforced valve spring kit BMW M42B18

€887.66 (tax incl.)

Kits of 16 reinforced valve springs for the BMW M42B18 four-cylinder from 09/1992.

Brand: SUPERTECH
Engine: M42B18 from 09/1992 (318i, 318is, 318ti E36)
Springs: double
Contents: springs, retainers, spring seats

The M42B18 four-cylinder from 09/1992

The M42B18 is the 1.8-litre, 16-valve twin-cam four-cylinder of the E36 BMW 318i, 318is and 318ti. From 09/1992 its valves move to a 6 mm stem, taken from the M50 VANOS: these kits are for that version.

From the factory, the engine has spring 11 34 1 739 472, retainer 11 34 1 724 991, spring seat 11 34 1 735 254 and 3-groove collets 11 34 1 461 405, with hydraulic tappets.

SUPERTECH reinforced valve spring kits

The spring pulls the valve back to its seat as soon as the cam lets go, and must keep it on the lobe. At high revs inertia wins if the load is marginal: the valve loses the profile, bounces and can meet the piston.

The three SUPERTECH kits of 16 double springs give 298, 356 or 418 N seat pressure at 35.7 mm, with titanium retainers.

Valve spring kit technical specification

Part number	Brand	Springs	Seat pressure	Kit contents
SPRK-H100DR-BM-16	SUPERTECH	Double 67 lbs	298 N at 35.7 mm	16 springs, 16 titanium retainers, 16 spring seats
SPRK-H1000D-BM-16	SUPERTECH	Double 80 lbs	356 N at 35.7 mm	16 springs, 16 titanium retainers, 16 spring seats
SPRK-H1005D-BM-16	SUPERTECH	Double 94 lbs	418 N at 35.7 mm	16 springs, 16 titanium retainers, 16 spring seats

Valve spring kit fitting details

Part	BMW original	Reinforced spring kit
Spring	11 34 1 739 472	Kit specific: SPR-H100DR, SPR-H1000D or SPR-H1005D, double
Retainer	11 34 1 724 991	Kit specific: RET-K20A2/T2 titanium
Spring seat	11 34 1 735 254	Kit specific: SEAT-BM60
Collets	11 34 1 461 405 (3 grooves)	Original kept

Each kit combines 16 double springs (SPR-H100DR, SPR-H1000D or SPR-H1005D depending on pressure), 16 RET-K20A2/T2 titanium retainers and 16 SEAT-BM60 spring seats. The original collets are reused.

Between the bottom and top retainers, with the valve resting on its seat, you measure the installed height. SUPERTECH quotes its pressures at 35.7 mm. A machined head or new valves can change this dimension; the more it grows, the lower the real pressure, by the spring rate for each millimetre. Measure every valve before assembly.

	SUPERTECH
Installed height	SPRK-H100DR-BM-16 : 35.7 mm SPRK-H1000D-BM-16 : 35.7 mm SPRK-H1005D-BM-16 : 35.7 mm
Seat pressure at this height	298 N 356 N 418 N

Technical guide

Our brands

SUPERTECH, a San Jose company in California, has worked on competition valvetrains for over thirty years. Its springs start as ultra-pure chrome-silicon-vanadium wire, its retainers as military-grade titanium, and each part is inspected by X-ray, ultrasound and laser.

How to choose

With more pressure, the valve follows the cam profile faithfully as the M42 climbs the rev range: that is what allows wilder camshafts, a later limiter or forced induction without valve float. SUPERTECH offers three levels for this engine, from softest to firmest, all with the same titanium retainers and spring seat.

Criterion

Key point

Choosing the pressure

The 67, 80 and 94 lbs in the SUPERTECH name express, in pounds, the force on the closed valve: 298, 356 and 418 N at 35.7 mm. Pick the level from three things: cam lift, the maximum rpm you are aiming for and any boost pressure the engine will run. On this engine with hydraulic tappets, stay measured: an overly stiff spring can collapse the tappets and wears the cams early. All three kits share retainers and installed height: only the pressure changes.

Single or double spring

All three kits use double springs: two nested springs sharing the work and calming each other's vibrations, topped by a titanium retainer that keeps the moving mass as low as possible.

When reinforced springs become necessary

Camshafts with more lift than stock
Maximum rpm raised by tuning
Turbo or supercharger fitted
Head rebuilt for hillclimb, circuit or rally
Tired stock springs, valve float near the redline

Compatible vehicles

Model	Engine code	Power	Years
BMW 318i, 318is (E36)	M42B18		09/1992-
BMW 318ti Compact (E36)	M42B18		1994-1995

OEM part number (valve spring): 11 34 1 739 472 (M42B18 from 09/1992).

Important: these kits cover the M42B18 built from 09/1992 (6 mm valve stem). Earlier M42 engines, with a 7 mm stem and double springs 11 34 1 727 768 and 11 34 1 727 769, are not covered.