[Jurassicgto]

Ok that's what I want, quicker and more. Bigger holes and short pump for more volume. Need lot's of fuel to get this car moving until the main circuits kick in. With 6 carbs and lots of cfm it takes a little while to get a strong signal to the main circuits going, especially with huge plenums. That's my theory anyway. We'll see what happens. Can always switch back with new venturi clusters if it doesn't work. Boring the pump well oversize, wow that's really thinking outside the box.

[Jurassicgto]

Just checked the diameter of my pumps, they are the 21/32 size, so there is room to bore out the wells for the 3/4" pumps. Wow, never thought of that. Thanks Carbking!

[Jurassicgto]

Looks like the wells would need to be bored to .730 and then polished. Now a trip to the machine shop.

[Tom Vaught]

Originally Posted by carbking

Back to the original posters question:

As to the feed versus slot discussion: sometimes engineers are asked to resign a product so that the product will still work although less reliably at a lower initial cost. In the manufacture of a carburetor bowl, much less expensive to cast in a slot rather than machine a seat, a hole, and a cross passage after the casting step. Jon.

Thank You Jon.

Tom Vaught

[bayside_norm]

Hope I'm asking this in the right place and not hijacking a thread. 66 gto tripower with no fuel pumped at the rear carb. I cleaned the carb guts, installed new pump, now its sending fuel to the nozzle nicely (on the bench, anyhow). But the bore is not filling from the bottom. It's been soaking in gumout for days, no luck. Any thoughts?

[mgarblik]

There is an inlet check system in the bottom of the pump well. I have seen the proper aluminum ball get stuck and not allow the well to fill. Also, I have seen the steel, (larger ball) incorrectly be installed in the inlet check in the bottom of the well and jam-up the circuit. If that has happened, the ball can be very hard to remove. I have seen extreme situations where a Chevy floating cup pump has to be used when the inlet check system is no longer usable due to a wrong or stuck inlet check ball. This is the area you need to look at. Good luck.

[bayside_norm]

I was afraid of that! Going to try once more to free it by drilling a tiny hole in the passage from the outside, and poke around with a wire. I will fill the drill hole with JB if it works. (Painting the carbs with Eastwood zinc chromate anyhow). This isn't a hard-core restoration but I'd like not to put 'those other guys' parts in there if I can make it work the way it's supposed to.

Thanks for the fast reply!

[Dick Boneske]

A while ago, I posted a procedure for removing the check ball from the seat under the accelerator pump using a 4"-6" long piece of 1/8" steel pipe.

http://forums.maxperformanceinc.com/...ator+pump+ball

Follow the procedure in that thread and you'll be able to remove ANY stuck ball in the accelerator pump well. In severe cases I have used 80W90 instead of motor oil, but plain old motor oil usually works.

Of the hundreds of Tripower carbs I've worked on, roughly half of them have a stuck ball in the accelerator pump well---many times because the large ball was put in that hole instead of the hole under the venturi cluster.

The suggestion of using a steel ball the same size as the check ball to form a new seat is a good one. They often don't seal due to corrosion. If this check ball doesn't seal, as is pointed out above, the pump discharge is reduced.

One more tip: Recently, I've had poor delivery from accelerator pumps on some Tripower carbs due to the spring that holds the ball down under the venture cluster. Some springs supplied in rebuild kits are too long, preventing the ball from rising enough to permit adequate flow to the squirters.

One last comment--on a Tripower or any multiple carb setup using Rochester 2 barrel carbs, there is PLENTY of fuel squirted into the venturis by the accelerator pump when the throttle is opened. That has always been one of the great things about Tripowers--the terrific jump from three accelerator pumps whenever the throttle is opened. A Quadrajet has ROUGHLY the same flow capability as a Tripower, but only one small accelerator pump instead of the three with Tripower. All Holleys use two pumps on their larger four barrel carbs, which is why they also give excellent throttle response--almost as good as a Tripower!!

[mgarblik]

Just read that post. What a clever idea on removing the stuck ball. Much better than drilling any type of exterior hole in the casting. Then you are always worried about the glue failing, a leak and a possible fire. I can't wait to try this on the next stuck one I run into! Similar idea to using grease to remove a stuck pilot bearing, which also works great.

[Tom Vaught]

Originally Posted by mgarblik

Just read that post. What a clever idea on removing the stuck ball. Much better than drilling any type of exterior hole in the casting. Then you are always worried about the glue failing, a leak and a possible fire. I can't wait to try this on the next stuck one I run into! Similar idea to using grease to remove a stuck pilot bearing, which also works great.

Mike, I have drilled a very few castings when nothing else seemed to work. Afterward I never glued the hole shut, I peaned the hole shut using a small ball pean hammer carefully closing up the hole. Then I glass-beaded the carb housing and other parts and had the carb parts re-plated. You could not tell the hole had ever been drilled.

Tom Vaught

[Dick Boneske]

As an added note, I've been able to get the stuck ball out of every carb I've used the outlined method on. Sometimes, it takes a half-dozen tries and results in a mess, but not too bad, since a piece of 1/8" pipe doesn't hold much oil. Holding a rag over the bowl opening helps keep the mess down and using a small hammer and quick, sharp taps is what works best. Heavier oil does work better!

[bayside_norm]

I tried banging the bowl upside down on a block of wood. Nothing. Two shots, and the D*** thing popped out. I polished up the seat with a soft plastic dowel and plastic lens abrasive so its nice and shiny. You guys saved me a ton of time, I was ready to drill out the lead plug and go at it. Thanks again!!! Awesome!

[bayside_norm]

Originally Posted by bayside_norm

I tried banging the bowl upside down on a block of wood. Nothing. Two shots, and the D*** thing popped out. I polished up the seat with a soft plastic dowel and plastic lens abrasive so its nice and shiny. You guys saved me a ton of time, I was ready to drill out the lead plug and go at it. Thanks again!!! Awesome!

I used gear oil in the threaded tube, probably doesn't matter. It worked GREAT. But after cleaning and polishing the check ball seat I noticed alot of corrosion and pitting. It's probably been stuck closed for the last 40 years. I dropped the new check ball in and depressed the pump spring to where it will be at full throttle, and the ball jammed in the passage. It took a few smacks to free it so I knew it was going to end up stuck again. I ended up gently grinding a new slightly flatter seat for the check ball, and now it falls out easily. Hopefully it seals also, it seems to be holding fluid on the bench. I'm going to let it sit for a few hours and see if I'm getting fluid backing up into the screen inlet. I think it's okay tho, all fingers crossed. Thanks again!!!