1.6/1.9 CVH Carburetor Spacer/Gasket-Insulator Comparison

UPDATE: When using a 1.9 or 1.6 HO manifold you want to use the 1.6 HO or 1.9 spacers because the metal tube helps direct air down the primary barrel's port opening on the manifold because the 1.9 & 1.6 HO manifold has a big square opening on the primary side so without either "tubed" spacer the air flow from the primary barrel will not be ideal... We have determined the 1.9 spacer is the best. Due to the design of the carb intake manifolds cylinders 1 & 2 have longer runner lengths than 3 & 4 so naturally the inner cylinders run rich while the outers run lean. The 1.9 spacer's tube helps restrict the inlet charge to the inner cylinders helping to provide a uniform air-to-fuel ratio across all 4 cylinders until the secondary barrel opens up. Sadly there is nothing to direct the secondary flow so it might be worth making something to cure this. After using the 1.9 spacer in my 1.6 for a while now the plugs are look very uniform, #2 & #3 are only ever so slightly more brown than #1 & #4. Unsure of any power increase but fuel economy might have been improved with me around 37mpg now. Definitely worth finding one if you can! Due to rarity I'll likely have to make my own some time using 1.6 spacers as cores.