Mk 2.5 Sport Inlet Camshaft

[Grandad]

Today my son (MJO) and I changed the cam belt on our recently acquired 2002 1.8 Sport. Whilst doing this we noticed a circular component mounted on the inlet cam shaft sprocket which we have not seen in any photographs in any books or on any internet threads. Does anyone know, please, what this is and what it does? Thanks.

[Busa_Rush]

Adjutable sprocket perhaps ? Got a photo ?

[MX-5 Lazza]

Mk2.5 have VVT. This is oil-pressure powered and electrically actuated. It works by adjusting the cam timing on the intake cam. What you see on the intake camshaft is part of the mechanism for this.

The books are all based on the Mk1/2 so won't show the VVT mechanism. Apart from this everything is pretty much the same as the Mk1/2.

[MJO]

Hmmm, should have realised that, thanks Lazza.