09-06-2024, 10:27 PM
Hi
That's a nice looking special.
All cars are slightly different, and 12 volt conversion might affect things, but an 800 RPM tickover and an ignition light that goes out at about 1000 RPM sounds pretty normal to me.
The SU mixture strength can be adjusted at idling speed, the needle has a pronounced taper around the idling position so only a small tweak to jet height via the adjusting nut is needed. I find a Colourtune plug useful, but the experienced can tell by ear. The effect of the adjusting nut on mixture higher up the rev/power range is small, and any mixture adjustment there is supposed to be accomplished by changing the needle.
I don't know whether you are using a 1933 low compression head or a post 1936 high compression head, but I have found that the latter is happier with less ignition advance, possibly because its design induces more turbulence.
That's a nice looking special.
All cars are slightly different, and 12 volt conversion might affect things, but an 800 RPM tickover and an ignition light that goes out at about 1000 RPM sounds pretty normal to me.
The SU mixture strength can be adjusted at idling speed, the needle has a pronounced taper around the idling position so only a small tweak to jet height via the adjusting nut is needed. I find a Colourtune plug useful, but the experienced can tell by ear. The effect of the adjusting nut on mixture higher up the rev/power range is small, and any mixture adjustment there is supposed to be accomplished by changing the needle.
I don't know whether you are using a 1933 low compression head or a post 1936 high compression head, but I have found that the latter is happier with less ignition advance, possibly because its design induces more turbulence.