The engine internals of this car were to a relatively period specification suited to rally/fast road.   Featuring an early 'flat top' 12G940 cylinder head, lightened internals and a Kent Megadyne 286 camshaft, and a lovely warm sounding full Maniflow exhaust system.  The key carb requirements were to select a suitable needle and springs for the Twin HS4 carbs.  Set the idle mixture, idle rpm, and choke idle rpm, and fully synch/balance the carb flow.  The second challenge was then to select the most suitable ignition advance curve from within the 16 pre-programmed Swiftune distributor. 

Final 'tune up' settings.

I had advised the client of a suitable SU needle and Spring ahead of my visit which was installed, and then checked by jet height, colortune, SU piston lift pin and CO gas analyser to cross verify each other at idle.  Ignition curve chosen was non-vacuum Swiftune CSI Curve 10 (Track Day/Rally) set at an idle of 11deg, with full advance to 30deg BTDC.  The client was quite happy to be shown this advance curve on a laptop and how it compared to such as the Calver CST Sport ignition curve and the well recognised Aldon Red ignition advance curves also suited to similar engine specs.

Notes - It may be possible to absolutely optimise final needle profiles on a Rolling Road (RR), however this client did not feel the need for his classic to be pushed hard on a RR for a max RPM figure and instead chose to optimise the normal driving RPM range.

Finally another much appreciated review left on social media for the service and attention to detail given to his engine tuning by AG Classic Car tune in co-operation with Reliance Garage, Helmsley, North Yorkshire.