As I mentioned in the other thread about using 1 1/8 SU's on an 850, actually, it would be better with quad 1 1/8 SU's, two each mounted on separate manifolds, being smaller you could get a good angle on the manifolds to mount the air-filters nice and neat close to firewall, now to the next question.
To make the linkages work, do you want 4 rights, 4 lefts, or each manifold with a left and right ?
As for needles, I have never looked at needles for a 1 1/8 SU , but the needles used on the Austen Healey bugeye sprite should work.
So why would I think about quad 1 1/8 SU's on an 850 ?
Air velocity would be the main point, and as for the CFM of air , it would be an interesting experiment, if a 12G295 is used and it has been machined and ported to give you 24cc chambers and the inlets have been given a slight clean out and finished with a rough grind you should maintain good velocity to the combustion chamber.
So what modified 850 would need this ?
Well, if you have a 998 A+ block, 850 thicktail crank , 998 pistons , the block decked to match, custom thrust bearings and other mods you should have an almost square 850, there is one already on the road with 12G295 head and Metro A+ cam and it makes good power , the owner is now looking at twin 1 1/2 SU's with a 544 cam - very Formula Junior .
So if anyone can provide some input on a quad 1 1/8 SU set up on an 850 , it should make interesting reading !
.