Triumph Repair: S.U. H6 carb,needles jets and all insides., modified street cars, haynes manuals

Question
Hi Howard, I need to know for suitability purposes,-
What are the needle sizes?jets, etc,for the SU H6 Carb when used on the CC series engines,
(over here we have CP series early 150hp cam,on injection, and Cr series 125 cam, 1972-on)
So you would be giving me the jet, etc sizes for the CC cam,but if you know what I should have in an SU carb for a CP or CR series I would be very grateful. And would the profile of the CC cam be very much different from either the CR or CP series? Cheers, Nick

Answer
Hi Nick,
I have tuned SU carburetors on competition cars and modified street cars but I found that it required tuning as per car and I could never say a certain needle and jet were going to work in any car. I found that I had to start with what I knew was going to be too rich and work my way down toward a leaner set up. From 30% to 40% richer than stoichiometric usually produces most horse power but is a little too rich for street use. I had a needle size and profile book from SU but I noticed that "Haynes" manuals has a "SU" manual with a very extensive needle profile size chart in the back plus recommended jets, needles and even springs for most applications. I don't think anyone can tell you what needles and jets to use on any engine with a certain cam. Because you can change the exhaust system and it will require a different jet and needle combination on that same car. I had to make my own needles on some cars as nothing was available to meet the needs of the engine.
Howard