Carb

[Highlander]

I have a question about the carbs on one of my cars. If you were looking down the throat of the carb the part of the air horn in the center has a hole that goes down into the carb. This is only on one carb the other one is blocked off. What is the hole for?

Carb

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[bbodie52]

You might be describing a Float Bowl Vent. There were several different types of vents over the model years, and you may have two different carburetors from different years. See the description under FLOAT BOWL VENTING on page 3 of the attached DELCO ROCHESTER - Models H, HV Carburetor Service Manual

[Highlander]

Yes Brad thank you! It is the vent. Do you for see any issues with using carbs with different style vents? I looked and do have more that will match will just need to rebuild. Is one style better then the Other

[terribleted]

carbs should match period. The 2 bases you are using might match, maybe only the tops do not match. Tops and bottoms should match in other words both carbs should be identical for best function.

[Highlander]

I guess I’ll use these for the time being less I have issues. This set came from Clark’s years ago. I will have to go through the carbs and find good matching tops, bottoms and rebuild them. Would it be worth putting a newer style carb with a power valve on instead of the 64 style?

[terribleted]

small difference if you have them I would.

[Eddddie]

My lM corvair clean tank rebuilt carbs from grant young.idle is fine increase speed left carb keeps popping This happens.in.neutral not driven yet Any thoughts?

small difference if you have them I would.

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[Eddddie]

9

My lM corvair clean tank rebuilt carbs from grant young.idle is fine increase speed left carb keeps popping This happens.in.neutral not driven yet Any thoughts?

small difference if you have them I would.

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Also compression good 110 engine

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[terribleted]

My lM corvair clean tank rebuilt carbs from grant young.idle is fine increase speed left carb keeps popping This happens.in.neutral not driven yet Any thoughts?

small difference if you have them I would.

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Popping sounds might be a sticking valve. Could also be a valve or valves adjusted too tight on the left side. Could also be poor carburation on that side (rich most likely). Are you sure the compression tests are good all over 110 and even within 20PSI (so 110-130 Minimum)? Could be a carb issue if compression, ignition timing, idle speed, etc. are all good. Given Carbmeister carbs I would certainly take them apart and re-rebuild them (starting with the left one) early in my troubleshooting...like right after verifying timing, and compression. I have had many poor carbs that supposedly have come from this source.

[Eddddie]

Thanks it is out of my league to do this I did not mention.my car has. Electronic ignition. crane now fast the timing was set before I have vacuum gauge I have a the uny s guage left carb adjusted ball in the middle on right carb put it on rh side.it stays at the bottom put my palm on top of left carb strong suction not so on rh carb its hard to find any one that knowes these cars

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[Eddddie]

Also compression is good 135 to150 on a cold engine that was not started for 4 years. Used a wrench engine could be turned

Thanks it is out of my league to do this I did not mention.my car has. Electronic ignition. crane now fast the timing was set before I have vacuum gauge I have a the uny s guage left carb adjusted ball in the middle on right carb put it on rh side.it stays at the bottom put my palm on top of left carb strong suction not so on rh carb its hard to find any one that knowes these cars

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[terribleted]

Either the carbs are adjusted way differently from each other (right side idle speed set way below the left side) or there is a blockage or problem in the right carb so that it is not flowing fuel and there fore does not have strong pull.

When using the Unisyn carb synchronizer you do the following. With the engine warm and idling (chokes should be fully open), First disconnect the adjustable carb to linkage rod from the linkage on the left carb. Next set Unisyn gauge on top of right carb. Adjust the Unisyn tool so that the bubble is in the middle of the tube. Next place the Unisyn on top of the Left carb. Adjust the left carb idle speed screw until the bubble is in the middle of the tube. Next adjust the linkage rod disconnected in the first step to cleanly enter the hole in the cross shaft and reinstall the clip. Idle speed at this point may be too high or too low. Next adjust idle speed screws on both carbs the exact same amount to obtain the desired idle speed of the engine. (Lets say the idle speed after Unisyn was too high...you would adjust the right carb and then the left carb idle speed screws down a little...perhaps 1/4 turn each...how is the idle speed still too high? Adjust both down another 1/4 turn...uh oh now the engine idle is a little too low.....adjust both idle screws up 1/8 turn...OHHH just right:) ) As long as the idle speed screws are adjusted evenly the carbs should still be balanced. You can repeat the Unisyn procedure to double check or refine the balance a little more perhaps, but, after this the 2 carbs should be pretty close unless there is an internal issue with one.

If the idle speed screw of a carb has little or no influence on the engines idle speed (in your case maybe the R carb?) then there is an internal carb issue either, very bad internal adjustment or blocked idle passages.

Redo the Unison balancing the correct way and if you are lucky it will be fixed.

[Eddddie]

Either the carbs are adjusted way differently from each other (right side idle speed set way below the left side) or there is a blockage or problem in the right carb so that it is not flowing fuel and there fore does not have strong pull.

When using the Unisyn carb synchronizer you do the following. With the engine warm and idling (chokes should be fully open), First disconnect the adjustable carb to linkage rod from the linkage on the left carb. Next set Unisyn gauge on top of right carb. Adjust the Unisyn tool so that the bubble is in the middle of the tube. Next place the Unisyn on top of the Left carb. Adjust the left carb idle speed screw until the bubble is in the middle of the tube. Next adjust the linkage rod disconnected in the first step to cleanly enter the hole in the cross shaft and reinstall the clip. Idle speed at this point may be too high or too low. Next adjust idle speed screws on both carbs the exact same amount to obtain the desired idle speed of the engine. (Lets say the idle speed after Unisyn was too high...you would adjust the right carb and then the left carb idle speed screws down a little...perhaps 1/4 turn each...how is the idle speed still too high? Adjust both down another 1/4 turn...uh oh now the engine idle is a little too low.....adjust both idle screws up 1/8 turn...OHHH just right:) ) As long as the idle speed screws are adjusted evenly the carbs should still be balanced. You can repeat the Unisyn procedure to double check or refine the balance a little more perhaps, but, after this the 2 carbs should be pretty close unless there is an internal issue with one.

If the idle speed screw of a carb has little or no influence on the engines idle speed (in your case maybe the R carb?) then there is an internal carb issue either, very bad internal adjustment or blocked idle passages.

Redo the Unison balancing the correct way and if you are lucky it will be fixed.

Thanks that seems easy enough

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