Technical Stumbles When Applying Brakes - HELP!

That channel across the front of the spacer is a heat passage that exhaust gassses pass thru. Where the exhaust comes out of the manifold and into that passage...... plug those holes!

 

Is there a specific or preferred way to plug em up?

 

They can be plugged with core plugs or you can tap them for a pipe plug or tap to a bolt size, cut off a piece of bolt and cut a slot in it to screw it in. Stake the thread lightly so it doesn't work lose.

 

An alternate method (although I don't like this many gaskets under a carb) is to use a factory gasket with the slot in it on the manifold, the stainless plate, a standard flat gasket (or a slotted one, doesn't matter) then the spacer and finaly a gasket, then the carb. Either method works, main thing is to get the exhaust gaskets out of that spacer. At this point you could use some JB to fill the crack and low spots and re-use the original spacer if you can't find a good substitute.

More than one way to skin a cat .... and the make fine taco's either way

 

Have you managed to remedy the fault and if so what was the problem?

 

Well, I installed the new riser plate and the problem still exists. I am honestly at a loss.
I think rebuilding the carburetor will be my last attempt at fixing the problem myself. If that doesn't work, maybe time for a shop to diagnose it.

Maybe the darn engine needs a rebuild after all? Low compression could cause the low vacuum I suppose, but there is no smoke from worn rings whatsoever. She does run rich though

 

Leak in diaphram of carb dashpot/powervalve? Are you measuring vacuum at intake or port on carb?

 

It is also possible in an old engine like that, that the timing chain has stretched and has jumped one tooth, thus retarding the cam. That will give you low vacuum and could be your problem. I have had a few 50's, and 60's cars that the timing chain has jumped on or was about to jump when I replaced it. If you remove the distributor cap so you can see the rotor move, you can see if the timing chain is stretched. Remove cap, turn the engine backward by hand until the rotor starts to move. Mark the dampener with tape or chalk, and now turn it forward just until the rotor starts to move. If it's more then 1/4" on the dampener the timing chain is bad, and may have already jumped a tooth.

 

You might want to look at the coil,I had them act crazy when starting,stopping and going around corners when the oil inside it gets low.

 

You said it only happens when appling the brakes. The only thing in common with the engine and the brakes is booster. It will draw in brake fluid if the master cylinder leaks. The engine will run bad with the added brake fluid. I know you said the master cylinder was new but it can still leak. The exact thing happened to me and it was fixed with a better m/c.

 

When adjusting the carb Turn the idle air screw in until you get the RPM you want then adjust the mixture screws to get the highest RPM or vacuum. then turn the Idle air screw in to reset idle then repeat. The idea is to get the idle air screw in as far as you can and still have the right idle RPM.

 

Does it stumble when you apply the brakes when it is not moving?

 

My bet would be the coil, the primary winding has come loose and when you put the brakes on it shorts out on the case cutting the ignition, swap it out and see what happens.

 

1932tub, in 1957 I was an apprentice at the 'Best damned garage in town', Mayfield's in Santa Clara.
The old man diagnosed a Chevrolet 216 problem as the winding 'floating' inside the coil...Sure as you live, he replaced the coil: instant repair. Red was sharp...

 

I learned that from an old hand as well Mike