ive . ▁The ▁device ▁was ▁commonly ▁referred ▁to ▁as ▁' Miss ▁Sh illing ' s ▁Or ifice '. ▁ ▁The ▁full ▁rem edy ▁was ▁to ▁use ▁the ▁B end ix - St rom berg ▁pressure ▁car b ure tt or , ▁which ▁allowed ▁more ▁precise ▁meter ing ▁of ▁the ▁amount ▁of ▁fuel ▁used ▁by ▁the ▁engine ▁and ▁prevent ed ▁fuel ▁star v ation . ▁This ▁new ▁car b ure tt or ▁was ▁used ▁from ▁the ▁Mer lin ▁ 6 6 ▁series ▁and ▁on ▁all ▁Griff on ▁engines . ▁In ▁these ▁engines ▁the ▁car b ure tt or ▁inject ed ▁fuel ▁at ▁ 5 ▁p si ▁through ▁a ▁no zz le ▁direct ▁into ▁the ▁super char ger ▁and ▁the ▁com pressed ▁air - f uel ▁mixture ▁was ▁then ▁directed ▁to ▁the ▁cyl ind ers . ▁The ▁final ▁development ▁was ▁the ▁SU ▁injection ▁car b ure tt or , ▁that ▁inject ed ▁fuel ▁into ▁the ▁super char ger ▁using ▁a ▁fuel ▁p ump ▁driven ▁as ▁a ▁function ▁of ▁c rank sh aft ▁speed ▁and ▁engine ▁press ures ; ▁although ▁this ▁was ▁fitted ▁to ▁the ▁ 1 0 0 ▁series ▁Mer l ins , ▁which ▁were ▁not ▁used ▁in ▁production ▁Sp it f ires , ▁it ▁was ▁used ▁in ▁the ▁Griff on ▁ 6 0 ▁and ▁ 8 0 ▁series . ▁ ▁Bo ost ▁pressure ▁measurements ▁The ▁British ▁measured ▁boost ▁pressure ▁as ▁l bs ./ sq . inch ▁( or ▁p si ) ▁above ▁a ▁nom inal ▁value ▁of ▁atmos pher ic ▁pressure ▁at ▁sea ▁level