Ball bearing in hose?

[mcditalia]

Why would someone plug the hose for the timed spark vacuum that connects from the distributor to the carb with a ball bearing? Never noticed it until now.

 

[Tom Bryant]

Good question. Does the vacuum can leak?

 

[Mac]

Why would someone plug the hose for the timed spark vacuum that connects from the distributor to the carb with a ball bearing? Never noticed it until now.

The ways of Bubba are mysterious and befuddling...

Mac

 

[Vettehead Mikey]

The ways of Bubba are mysterious and befuddling...

Mac

Especially if they left the vacuum port on the carb unplugged.

 

[DGVETTE]

Vacuum Advance

Years ago, many years ago during Muscle Car era I would pull vacuum line, plug it, and advance distributor timing. This increased power while at drag strip. Then I would reconnect vacuum line and reset timing for drive home. Vacuum advance was for fuel mileage. Performance and race engines had distributors without vacuum advance.
Not saying this only happened at drag strip and no where else.
Probably not the reason here, just my experience.

 

[Tuna]

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What he said.

Might want to check the initial and total advance on this engine just to know what it's doing before you decide to hook the vacuum back up.

 

[the boss]

Why would someone plug the hose for the timed spark vacuum that connects from the distributor to the carb with a ball bearing? Never noticed it until now.

Most of the time it was a pre-ignition problem (ping), when vacuum advance was working the engine was probably pinging on acceleration or on load when it was hot. I saw a lot of people pluging the hose and giving 2 or 3 degrees on base timming to get a fair performance without the pinging problem. there was a lost of power but if you never drove the car whit the system in operation, you cant notice the difference. If you get the systeme to work normaly, you should get a better performance overal, better acceleration, trottle response from start and some fuel economy

 

[Mac]

Thank you for the input, guys! I hope I didn't offend anyone with my remarks re: Bubba.

I've never used a ball bearing for a plug, nor have I left the vacuum advance blocked for anything other than troubleshooting. Mind you, I've never turned a Vette for drag racing...

Mac

 

[Vettehead Mikey]

Thank you for the input, guys! I hope I didn't offend anyone with my remarks re: Bubba.

I've never used a ball bearing for a plug, nor have I left the vacuum advance blocked for anything other than troubleshooting. Mind you, I've never turned a Vette for drag racing...

Mac

What the guys said above was disconnecting the vacuum canister and plugging the line going to the carb to prevent a leak. The OP found the line still attached to the vacuum but plugged- which accomplishes nothing.

That's Bubba in anybody's book. otfl

 

[LLC5]

Why would someone plug the hose for the timed spark vacuum that connects from the distributor to the carb with a ball bearing? Never noticed it until now.

Your picture shows it being done backwards, usually the BB is placed at the end of the circuit for easy removal if needed and not the source, in this case at the vacuum can. The desired result will work either way, it's just easier if done at the circuit being bypassed.

It is usually done to hide something such as a visual emission test, potential buyer, judging, etc.

 

[mcditalia]

What the guys said above was disconnecting the vacuum canister and plugging the line going to the carb to prevent a leak. The OP found the line still attached to the vacuum but plugged- which accomplishes nothing.

That's Bubba in anybody's book. otfl

This find has been there for the past decade. Never realized it was plugged until now. The vacuum line was still attached but non functional, which would indicate that the OP wanted to take it out of the equation. Never had any noticeable problems, but Im just trying to figure out whether it could be one of the causes with a recent symptom:

Car fully brought to operating temp, under light to moderate steady load and will stumble/detonate right before throttle is increased sharply, then will get going.

 

[mcditalia]

Your picture shows it being done backwards, usually the BB is placed at the end of the circuit for easy removal if needed and not the source, in this case at the vacuum can. The desired result will work either way, it's just easier if done at the circuit being bypassed.

It is usually done to hide something such as a visual emission test, potential buyer, judging, etc.

Actually the ball bearing was on the distributor side, just mocked it up for the picture.

 

[mcditalia]

Good question. Does the vacuum can leak?

Not sure. I will run the car without bb and see the effects. Will update......

 

[Verle]

Thank you for the input, guys! I hope I didn't offend anyone with my remarks re: Bubba.

I've never used a ball bearing for a plug, nor have I left the vacuum advance blocked for anything other than troubleshooting. Mind you, I've never turned a Vette for drag racing...

Mac

I know Bubba.
Bubba is a friend of mine.
Bubba is also dumber than dirt sometimes!. :eyerole

 

[Vettehead Mikey]

Car fully brought to operating temp, under light to moderate steady load and will stumble/detonate right before throttle is increased sharply, then will get going.

Is that stumble AND detonate? Too much vacuum advance at steady cruise speeds can cause surging or detonation at throttle tip in. It would be unusual if you're seeing either/both with the vacuum advance already inhibited (?)

 

[mcditalia]

Is that stumble AND detonate? Too much vacuum advance at steady cruise speeds can cause surging or detonation at throttle tip in. It would be unusual if you're seeing either/both with the vacuum advance already inhibited (?)

That is correct, both a stumble and detonation occur before the car responds to sharp throttle.

 

[Tom Bryant]

Interesting. What is the base timing set at? Have you checked to see if the ring on the balancer has slipped? The problem could be way too much initial timing. Does it crank hard on starting?

Also it could have a lot of carbon on the pistons and in the chamber that has sharp edges that get very hot and cause pre-ignition.

Tom

 

[Tom Bryant]

You can check your vacuum can by applying vacuum to it and pinching off the rubber line. It should stay activated until you release the vacuum and then snap back. If you have a hand vacuum pump use that or put the hose on it an suck on it (if you have good lungs).

Tom

 

[DGVETTE]

Sharp Throttle?

Does the car accelerate normally with a slow gradual push on accelerator pedal? But a sudden and aggressive push results in stumble. If this is case, the accelerator pump in carburetor may not be supplying enough fuel or no fuel at all.

Now back to original post asking why is the vacuum hose to distributor blocked off .
Someone(Bubba?) removed hose to set the engine idle ignition timing and didn't hook it back.
Or.
There is a problem within the distributor with vacuum advance. (1)The advance diaphragm is busted and leaking vacuum. (2)The breaker plate may be binding and not responding to vacuum properly. Someone(Bubba again?) plugged the hose as a work around.
Simple fix in one case, reconnect hose, but second case will require checkout and repair of distributor. Check of idle and advance timing should be done in any case.
Then hope Bubba didn't change anything else. :eyerole

 

[mcditalia]

You can check your vacuum can by applying vacuum to it and pinching off the rubber line. It should stay activated until you release the vacuum and then snap back. If you have a hand vacuum pump use that or put the hose on it an suck on it (if you have good lungs).

Tom

Uhm, will try that tomorrow when the weather clears up. Is this with car runiing or off?