'65 carburetor

[jframe]

Anyone have a GOOD 65 carb, ready to go? I have the 4gc on mine, but I don't care which brand it is, I'm just tired of trying to tune this one. Has a flat spot if you step down pretty hard from idle, but then it runs out good. Noses over like it's out of gas. Don't really care about rebuilding it, would rather have one that's ready to go.

[RivNut]

All 4GC's are Rochester carburetors.  Sounds like an accelerator pump issue.  If you want it to be numbers correct, you have the choice of another Rochester or the correct Carter AFB.

[jframe]

42 minutes ago, RivNut said:

All 4GC's are Rochester carburetors.  Sounds like an accelerator pump issue.  If you want it to be numbers correct, you have the choice of another Rochester or the correct Carter AFB.

Yes, I am looking for either the Rochester or Carter that is correct for the '65 so it will have all the kickdown provisions and so forth for the kickdown linkage.

[1965rivgs]

7 minutes ago, jframe said:

Yes, I am looking for either the Rochester or Carter that is correct for the '65 so it will have all the kickdown provisions and so forth for the kickdown linkage.

You can use a `66 carb if you have a 401 and the numbers are not important to you

Tom M

[RivNut]

3 hours ago, 1965rivgs said:

You can use a `66 carb if you have a 401 and the numbers are not important to you

Tom M

But not a carb from a 66 Riviera. Those are Rochester Quadrajet carburetors. They are a spread bore design and require a different intake manifold.

[carbking]

Before spending money on a different carb, try checking the timing, and readjusting the idle.

 

Verify the timing

Warm the engine

Increase idle by turning the throttle positioner screw clockwise

In turn, turn each idle mixture control screw all the way in, and then back out 1 1/4 turns

Reset the idle using the throttle positioner screw

Test drive

 

Cheaper than a carburetor.

 

Jon.

[60FlatTop]

52 minutes ago, carbking said:

Verify the timing

 

Vacuum and mechanical advance.

 

And if you have a pipe to hose fitting in the manifold with a one inch piece of hose connecting to tubing, be sure the hose isn't cracked.

[jframe]

1 hour ago, carbking said:

Before spending money on a different carb, try checking the timing, and readjusting the idle.

 

Verify the timing

Warm the engine

Increase idle by turning the throttle positioner screw clockwise

In turn, turn each idle mixture control screw all the way in, and then back out 1 1/4 turns

Reset the idle using the throttle positioner screw

Test drive

 

Cheaper than a carburetor.

 

Jon.

Jon, I may have just been frustrated. Got up this cold morning and re-seated the mixture screws befor I ever cranked the car, then backed them out 1 1/4 turns. They were backed WAY out; prolly 2 1/2 to 3 turns. Car cranked rught off, warmed it up and drove it til it got up to temp. Seemed MUCH better, and didn't even touch the idle screw on the linkage. Thanks for the advice from all you folks, I'll report back if it has any more troubles.

[60FlatTop]

5 hours ago, jframe said:

Got up this cold morning

 

Cold? Two degrees at 6 AM. We don't even have to put the ice cream away.

[carbking]

Glad it worked for you.

 

This is often an issue, and generally incorrectly diagnosed as a bad accelerator pump.

 

Setting for the "fattest" idle will often cause the throttle plates to be closed too far to allow any air velocity past the idle transfer circuit, effectively disabling this circuit. The idle mixture will then be too rich (compensating for the lack of air velocity) and droplets of fuel will adhere to the runners of the intake manifold (called "puddling").

 

When the throttle is opened rapidly, there will be sufficient air velocity to sweep these droplets into the cylinders, creating an instantaneous over rich condition. Since the idle transfer circuit was disabled by the lack of air velocity, there is no inertial fuel flowing through the idle transfer circuit, creating an instantaneous lean condition just after the instantaneous rich from the droplets. A hesitation, or bog results. Now, if the bog is not so severe as to stall the engine, the squirt from the accelerator pump arrives, and all is good.

 

Each carburetor has a "range of idle adjustment" specified by the manufacturer; and generally ignored.

 

If I had a dollar for every "defective" accelerator pump that was erroneously replaced and the idle adjusted over the last 50 years, I could buy Hawaii, and retire

 

Jon. 

Edited February 15, 2020 by carbking (see edit history)

[carbking]

Bernie - unless you purchase in large quantities, there is NEVER a reason to "put it away"

 

Jon.

[jframe]

6 hours ago, 60FlatTop said:

 

Cold? Two degrees at 6 AM. We don't even have to put the ice cream away.

One of the good things about North Alabama; cold to us is anything below 50°

[RivNut]

How many of you know the facts about the saying "cold enough to freeze the balls off a brass monkey?" Or is that just an urban myth? 🤔

[Craig Balzer]

It is widely believed that a brass monkey is a brass tray used in naval ships during the Napoleonic Wars for the storage of cannonballs (piled up in a pyramid). The theory goes that the tray would contract in cold weather, causing the balls to fall off.

 

BUT

 

This theory is discredited by the US Department of the Navy and the etymologist Michael Quinion and the OED's AskOxford website for five main reasons:

 

• The Oxford English Dictionary does not record the term monkey or brass monkey being used in this way.
• The purported method of storage of cannonballs (round shot) is simply false. Shot was not stored on deck continuously on the off-chance that the ship might go into battle. Indeed, decks were kept as clear as possible.
• Such a method of storage would result in shot rolling around on deck and causing a hazard in high seas. Shot was stored on the gun or spar decks, in shot racks (longitudinal wooden planks with holes bored into them, known as shot garlands in the Royal Navy), into which round shot were inserted for ready use by the gun crew.
• Shot was not left exposed to the elements where it could rust. Such rust could lead to the ball not flying true or jamming in the barrel and exploding the gun. Indeed, gunners would attempt to remove as many imperfections as possible from the surfaces of balls.
• The physics do not stand up to scrutiny. All of the balls would contract equally, and the contraction of both balls and plate over the range of temperatures involved would not be particularly large. The effect claimed possibly could be reproduced under laboratory conditions with objects engineered to a high precision for this purpose, but it is unlikely it would ever have occurred in real life aboard a warship.

[RivNut]

 

😄