I noticed that the hole in the new spray nozzles for Holly NH carbs is smaller than the hole in the original nozzles. Is this a problem or should I put the old one back in?
Carefully drill out the repro to the original size. Why can't those repro boys do stuff right?
Larry, what size should the hole be? I don't why so many reproduction parts for model T's are incorrectly made but, it's annoying to buy parts that don't fit without modifying them.
***Stop right there!!!***
If you went and drilled out your new reproduction Holley NH spray nozzle, then you need to throw it away and buy another one. DON'T INSTALL IT IN A CARBURETOR or what you end up with will be no better than what you started with...
The reason your new spray nozzle has a smaller hole than all the used ones you have looked at is because all the old ones have gotten enlarged from of all the years of getting the spray needle torqued too tightly down into them!!!
What appears to be a "larger" hole in the "original" is in fact WEAR, and is not an indication of a problem with the new one.
I'm real surprised that Larry didn't pick up on that right away and that none of the "carburetor gurus" have responded yet.
Hmmm,....hard to understand how there can be any "wear" in the hole in a spray nozzle,...???
That hole is through about 1/8" of steel. I can imagine the end of the hole toward the needle (inside the tube) becoming enlarged from over-tightening. But is it possible to get the needle so tight, so many times, that the needle wears its way through that 1/8" of steel and the opposite end (outside the tube) is also over-sized?
I just compared a no apparent wear original NH spray nozzle to a reproduction I bought last month from Langs. Both have a 1/16" hole in the center, a new 1/16" drill shank fits snug in either one.
Some of the spray nozzles that come from old carbs are rusted and may actually be smaller inside diameter due to corrosion. Any wear could be caused by dirt in the fuel but the real problem I see is restricted flow from corrosion.