Are you looking for more performance from your S3, S4, S4s Turbo Esprit or Lotus 900 series engine?
Installing performance valve springs ensures a reliable increase in power that is usually found further up the RPM range.
The standard valve springs will normally experience problems in accommodating the demands imposed by the valve train and any increase in camshaft lift.

Lotus Marques offers performance spring sets that can accommodate a valve lift of 0.500” (12.70mm) and can control the valve train to in excess of 8500rpm.
Great care has been taken to ensure that these components are of the highest quality and can withstand sustained high rpm.
These springs are supplied with engineering drawings that provide details of recommended installed heights and subsequent valve seat pressure.
Depending on which cylinder head you have and its condition, some preparation work may be necessary such as installing new valves, valve guides, seats etc. 
It may also be necessary to carry out machining under the spring seat to obtain the correct valve seat pressure.

This preparation work can be carried out by Lotus Marques and we would be pleased to supply a quotation for supplying parts and machining services.

The kit contains the 16 duplex springs and installation drawing.