Got a bunch of double pumper parts in the other day (sorry Ron.....no pump cams ;op) and I can across this one. What is going on here? I was checking to see if they are primary or secondary and I usually try to blow through the vacuum port to see if it's plugged. This one does have the hole that would normally be used for timed advance but there are no threads for the fitting (older style). The main thing I don't get is the holes above the jets. Is this where the nitrous bungs get welded in? LOL
I just don't get why there would be holes above the jets. Doesn't look like a home job either. Hole are very clean and it's hard to drill on something round. Any guesses????


http://i120.photobucket.com/albums/o182/agentjdub/meteringblock002.jpg


http://i120.photobucket.com/albums/o182/agentjdub/meteringblock001.jpg

Holley didn't do it! Perhaps someone misunderstood just what it was you are supposed to drill out to increase jet size.:eek:

I think those holes are the new Holley jet size #140!!!

That's a Holley, double dual jet metering block!:yes::D

They could've saved some time and just left the jets out and had the same flow...

dang thats a holley??????

So what I'm gathering is that I need to go to my favorite lake and see how many times I can skip this across the water??? :p lol

I've seen those kind of modifications on alcohol carbs. With alky its almost impossible to get enough fuel flow through standard jets. The drilled holes flow a known amount (figured out by the carb builder) and the actual jets do the final adjustment.

Well Jon, I am ready and willing to make you a smoking deal on this highly modified alcohol metering block!!!

What's funny is that this came from an engine builder with a dyno. He might have been exper-menting!