I guess there could be as many replies as members!
My tuppence worth - I bought a 1 1/4" Morris 1098cc SU in a jumble sale in the 1980's for £1; took it home, cleaned it up with paraffin & a toothbrush and fitted it to my Ulster rep. I fiddled about with the idle adjustment for a while but it's been on my car ever since and runs just fine (if perhaps not 'optimally'). This particular carb is identifiable by a small triangular tab on top of the float chamber marked 'AUD13'. It has a red spring and AN needle.
I have no doubt at all this set-up could be improved on, but it provides a perfectly good runner.
My received wisdom is that a light blue spring AUC4587 and No.6 needle AUD1005 are favoured by the racing fraternity (not sure which choke size this goes with though, or how driveable it is off the track). Springs & needles can be had from Burlen or Mini Sport.com.
Chris
p.s. I just had to pop out and check, but I also have a 1 1/4" SU on my Nippy and that's an AUD431L. According to the book that's from an MG1300, and has a GY needle and blue spring; though I can't swear these weren't changed without stripping it I'm afraid. The Nippy has been lying fallow for a bit, but used to go like the proverbial clappers. Incidentally on this car I used a Reliant SV exhaust manifold, which has an integral inlet casting, and fabricated a short angle adaptor from steel tube for the carb.
My tuppence worth - I bought a 1 1/4" Morris 1098cc SU in a jumble sale in the 1980's for £1; took it home, cleaned it up with paraffin & a toothbrush and fitted it to my Ulster rep. I fiddled about with the idle adjustment for a while but it's been on my car ever since and runs just fine (if perhaps not 'optimally'). This particular carb is identifiable by a small triangular tab on top of the float chamber marked 'AUD13'. It has a red spring and AN needle.
I have no doubt at all this set-up could be improved on, but it provides a perfectly good runner.
My received wisdom is that a light blue spring AUC4587 and No.6 needle AUD1005 are favoured by the racing fraternity (not sure which choke size this goes with though, or how driveable it is off the track). Springs & needles can be had from Burlen or Mini Sport.com.
Chris
p.s. I just had to pop out and check, but I also have a 1 1/4" SU on my Nippy and that's an AUD431L. According to the book that's from an MG1300, and has a GY needle and blue spring; though I can't swear these weren't changed without stripping it I'm afraid. The Nippy has been lying fallow for a bit, but used to go like the proverbial clappers. Incidentally on this car I used a Reliant SV exhaust manifold, which has an integral inlet casting, and fabricated a short angle adaptor from steel tube for the carb.