Notches on SU butterflies
Posted: Tue Sep 07, 2021 10:36 am
Some time ago I bought what was supposed to be a pair of SU HIF6 carbs from a Rover V8 to rebuild and replace my old and probably worn ones but have only now noticed that they're not actually a pair, one has a plain round butterfly and a little brass 'jet' that's very slightly below the surface just like the ones on my engine at the moment but the other is different with a small notch in the bottom engine side that fits over a raised little brass 'jet'.
I haven't taken them apart now, there's no point if I can't use them and there may be other internal differences although they do look similar externally.
I can't see any mention of this difference in Hardcastle's SU tuning book and SU's website doesn't help either and to cap it all off the little identification tags are missing too.
I assume I've been sold 2 carbs from 2 different engines that won't actually work as a pair?
Edit - wrong author, it's Hammill not Hardcastle.
I haven't taken them apart now, there's no point if I can't use them and there may be other internal differences although they do look similar externally.
I can't see any mention of this difference in Hardcastle's SU tuning book and SU's website doesn't help either and to cap it all off the little identification tags are missing too.
I assume I've been sold 2 carbs from 2 different engines that won't actually work as a pair?
Edit - wrong author, it's Hammill not Hardcastle.