Fine Carburetor Tuning Using Fish Tank Accessories - Regulated Vacuum Leak For A Cleaner Idle

Not carb related, but I used a similar valve to regulate the vacuum modulator of the C-4 in my old Mustang back in the '80's to raise the part throttle shift points.

Geeze Tony, your bag o' tricks never ends. This is priceless. I bet once you get this set up right and start experimenting a bit your understanding of things just gets sharper. All these tricksakes me want to take another swing at running a tunnellram on the street

Thanks Uncle Tony on your tip with the aquarium valve, stuff like this is why I love this channel. I guess all the pet stores will be busy Thursday with aquarium valves flying off the shelves, make sure everyone mention's Uncle Tony and they may send him free dog food for his dogs!

Cool trick!!! For a streetcar, I've also had good luck stepping up to a larger orifice sized PCV valve to add air to get my idle adjustments back in range.

Did you hear about the brawl at the fish and chip shop? Many fish were apparently battered!

Excellent tuning trick! This bubbler regular idea has many applications. In a previous video, Uncle Tony showed us that Edelbrock has a new, modern carburetor which has additional air bleeds to adjust for this rich idle condition. This bubbler regulator is a heck of a lot cheaper than buying a new carburetor.

Must be why the new Edelbrock race carb has the adjustable air bleed?

Thanks that could have saved me years of cleaning spark plugs. I advanced the timing and adjusted the idle mixture with an air/fuel gauge. That fixed it almost completely on a mild race cam.

I’ve done this on the vacuum advance can, it works well to delay vacuum signal to the can preventing detonation on off idle acceleration. It dampens the sudden rush of vacuum signal when accelerating from cruising to overtaking speeds as well. Works great when setting your engine timing on the limit or tuning for economy.

Drilling the throttle plates I knew about. What you have just shown is artistic in it's use and you don't have to braze the plates if you go too big. Old school being taught to new and old rev heads.

Very neat solution. A controlled vacuum leak with a valve. I'll have to play around with that concept. Nice video Tony

This is very clever. It sort of reminds me of the electronic tuning system Thunderhead289 did on the Ford he ran the lawnmower carb on.

Uncle Tony - I hope your viewers listen very well (and do) what you suggest in terms of adding idle air using the fish bubbler valve. I did this some 35-40 years ago when I was tuning a 10.4:1 compression Ford 460 engine to pull a heavy camper 'cause IT REALLY WORKS! Of course I did many other things in tuning that engine that I've written in before, so I won't go into the other things here. Your info is good stuff and I take you very seriously.

Uncle Tony you constantly show me hacks that I haven't seen before. Love your teaching.

Excellent. I've been drilling throttle blades forever. This is much easier 😊

Pro Tip: This trick works especially well on Plymouth Barracudas and AMC Marlins.

These old school hot rodding secrets are exactly why I watch this channel. Good stuff!!!

I'm ordering some of these valves right now! So goddamn simple I can't believe I've never thought of this or heard of this before thanks again Uncle Tony!

For a street engine and not wanting to drill out the throttle blades the regulator valve is a good option but I use it as a last resort. I set my throttle blades so they are just on the edge of the transfer slots, bottom edge of blades sitting right at bottom edge of slots. Set idle mix and use minor adjustments in timing to achieve a good idle. If Idle is still not right and mix screws aren’t responding I will adjust the float to get a little more or less fuel into the idle circuit. Higher fuel level will fatten the mixture, lower level will lean it out a bit. An 1/8” difference in float level will make a significant difference in how much fuel is pulled through the idle circuit. Usually a 1/16th change is enough to make a difference. That’s about the difference of fuel dribbling out of the sight hole vs not dribbling out. A lot of people still run vacuum advance dizzys on street engines with moderate to large cams ( I do when I can) and the bypass valve complicates that setup. No vacuum advance…the bypass valve is a quick and easy fix but you should still try to tune without it first. It is a forgotten trick, I haven’t seen it on a carb in 25 years but then I haven’t been around a drag car for that long either.

I'm so glad you made this video. It's a hell of a learning curve to the whole hotrod thing when no one around you has any experience with it.