Secondary Metering Block Calibration

JedIEG said

I'll have to tap out the block since the emulsions are not adjustable on this metering block. Should I swap the IFR to the lower position or does it really matter on a secondary side? SIAB size seem ok?


The QFTs come with plates that are tapped for using regular main jets so it is actually a #74 jet out of the box.

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Yes, lower the IFR even on the secondary side.

Did you actually pin the emulsion holes? I’m asking because you can’t go by what the paperwork says. I’ve done enough of these to know they can say .028 on the paperwork but when you pin them I’ve seen them as big as .033. Just want to be sure on that.

Yeah, you’ll have to drill and tap those for a set screw. I always drill all the way through to the channel with an .062 drill bit and then drill for tap size. That way, if for some reason you may need a bigger than .028 emulsion bleed you can get it. If you leave the .028 hole there you will never get bigger than .028. FWIW, I can’t think of a time when you’d need more than .028, but I hate taking chances.