Meanwhile, the main body is...
Meanwhile, the main body is clamped into the milling machine so all the surfaces can be milled flat and true to ensure a good seal upon reassembly.
Meanwhile, the throttle plate is machined for and fitted with a new Teflon throttle shaft for proper throttle shaft clearance. Krup says, "this is just about 0.001-inch. The Teflon bushings don't require any kind of lubricant. Holley has a steel shaft in a dry aluminum throttle plate. That's just asking for problems. Teflon holds the shaft in place, and it can run dry. We put in lube holes so that if you ever get dirt or debris in it, you can use one of those little red tubes that come on WD40 cans that will slip right in there and blow any kind of dirt or debris out of that area."
Then, after blasting, the...
Then, after blasting, the main body and fuel bowls are tumbled for 45 minutes to get them ready for their new finish.
At this point, the carb gets glass beaded again before having a final alodine finish applied and reassembled with brand-new parts. We elected to have some modifications done to our carb from a host that Willy's is capable of.
"As far as the calibration is concerned, we replace all the air bleeds in the body," Krup says. "We didn't change the boosters on this one-that's a modification we do, but this one came out close enough on size to where we didn't have to."
Krup is looking for a certain air/fuel ratio when the carbs are dyno-tested. He says, "That's usually right around 12.7:1 to 13.2:1. The air bleeds help us tailor that air/fuel ratio on the top end. There are also idle air bleeds that help us tailor the idle up to about 2,500 rpm. If the air/fuel ratio starts getting a little rich on us once we get past 6,000 rpm or so, we'll go in there and open up the air bleeds a couple of thousandths. That will give us the same mixture through the midrange, but the top end will be a little leaner."
After tumbling, the main body...
After tumbling, the main body and fuel bowls are almost too pretty to consider bolting on top of something as barbaric as an internal combustion engine.
Same thing for the refurbished...
Same thing for the refurbished throttle body.
The reassembled throttle body...
The reassembled throttle body with brand-spanking-new components. Note the small holes drilled through the throttle plates. These will help the carb idle well on top of an engine with a very lopey camshaft.