Can someone tell me if Holley jet sizes are the same as a decimal drill size? Eg Is a 63 jet the same size as a .063 drill bit (54 on the # size)? We had to do some last minute tuning on a Holley bugspray(94) and ended up opening up a 60 jet to a .063 drill size. I hear different things about drilling jets so I 'd like to get the proper jet. The car runs much better so I know we're in the ballpark right now. Thanks for any info or tips.
From Holley's web page; Also, from some dudes web page, a chart listing a correlation between jet size and drill size; http://www.angelfire.com/fl4/pontiacdude428/HolleyInfo.html In all of the jetting we due, we have a wire size and letter size drill set that we use
Going by that chart the drill size almost matches up. I'll get a 64 and we should be good. Thanks for the link.
Holley main jet sizes are not numbered by drill size and are never suppose to be drilled as it alters the flow characteristics.
Agreed, sometimes drilling them out can even reduce the flow. Spend a few bucks and get the correct jet.
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