All 45mm on Q/QV/Q4I thought the Q cars had 44mm on them that is why I asked? I would love to put some new ones on it.
Here is the deal.From my aircraft engine design classes in college, It was critical as to what the intake dia, ie, potential mass flow, was in comparison to cylinder volume, valve size, piston speed, and cam timing, etc. If the mass flow velocity into the intake is too low, esp at low engine rpm, then the amount of air crammed into the cylinder during the intake stroke before the valves slam shut is reduced due to lower momentum of the incoming charge, allowing some of the charge to be forced backward out, or at least stymied in it's flow as the piston rises. There is a supercharging effect in these designs.
I had this illustrated to me quite clearly with my old Downton prepared Cooper S mini. The larger intake (1 1/2 inch carbs instead of 1 1/4 inch) and the AEG 648 cam resulted in mixture being pushed BACK out of the intake (onto the firewall) at below about 3000 rpm. Then, as that rpm was exceeded, the velocity was sufficient to keep the charge in the cylinder when the cam closed the intake valve, and away we would go.
Friend of mine raced a 1300 Giulia Sprint Coupe Veloce which had an engine which was soooo "cammed" that it wouldn't run worth a **** below about 4500 rpm (seemed like about 5 hp), but had a shift point of 9000-9500 rpm, with an idle of about 2500 rpm. Really difficult to drive except in a race, but oh so fast.
Bottom line for my feelings is that the LS engine with the Q runners does not fall into that regime being just a choked down Q.