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PostPosted: Tue Feb 19, 2019 9:53 am 
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Location: Salem, Oregon
Car Model*: 58 Plymouth Plaza 2dr, 63 Valiant Signet 200 2dr
It's not uncommon to have the outer ring of the damper slip a few degrees. To verify whether the outer ring has slipped requires the use of a piston stop installed through the #1 spark plug hole, rotating the crank towards TDC on compression stroke for #1 and mark where it stops, then turning the crank counter-clockwise until it hits the piston again and mark that location.

The point halfway between the 2 marks you made is TDC. If halfway between those points isn't 0 degrees on the original markings, the outer ring has slipped. Fortunately, you can remark the damper by making new marks on it using the built in template of the original marks.

There doesn't need to be obvious signs of failure for the outer ring to slip.

~THOR~

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1958 Plymouth Plaza 2 door Club Sedan
1963 Plymouth Valiant Signet 200 HT - "CL4P-TP"
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PostPosted: Tue Feb 19, 2019 10:16 am 
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3 Deuce Webber

Joined: Mon Feb 11, 2019 9:15 am
Posts: 53
Car Model*: 1965 Dodge Dart, 225 Slant Six
THOR wrote:
It's not uncommon to have the outer ring of the damper slip a few degrees. To verify whether the outer ring has slipped requires the use of a piston stop installed through the #1 spark plug hole, rotating the crank towards TDC on compression stroke for #1 and mark where it stops, then turning the crank counter-clockwise until it hits the piston again and mark that location.

The point halfway between the 2 marks you made is TDC. If halfway between those points isn't 0 degrees on the original markings, the outer ring has slipped. Fortunately, you can remark the damper by making new marks on it using the built in template of the original marks.

There doesn't need to be obvious signs of failure for the outer ring to slip.

~THOR~

Really? Well thanks for the information! I don't have a piston stop tool but I have an endoscope at my disposal so I can check it somewhat accurately with that.


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PostPosted: Tue Feb 19, 2019 5:46 pm 
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Location: Sonoma, Calif.
Car Model*: Many Darts and a Dacuda
Quote:
- Valvetrain doesn't seem to be noisy...

All this carb work...

I may have missed this but... did you ever actually check the valve lash adjustment?

Tight valve lash will cause the engine to run poorly.
Pull the valve cover and confirm the the valve lash is set correctly... before doing anything else.
DD


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PostPosted: Tue Feb 19, 2019 6:11 pm 
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Joined: Sat Feb 18, 2006 2:19 pm
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One thing I wonder is how much the float bowl vent valve adjustment matters? A lot, if that is open or leaks when is supposed be closed, atmosphere pressure will enter carb bowl, forces carb to run rich. Balance tube between carb bowl and venturi keeps air pressure equal inside carb. Venturi pressure is always slightly lower than atmosphere pressure and as load increases lower still. That bowl vent lets vapor escape at curb idle, prevents hard starts after heat soak, fuel gets to hot after shut down turns to vapor.


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PostPosted: Tue Feb 19, 2019 6:18 pm 
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http://imperialclub.org/Repair/Lit/Master/ Go here and go down to 1966 there 2 carb movies and articles


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PostPosted: Tue Feb 19, 2019 7:52 pm 
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Good call, Doug. That is usually the first thing I suggest and it slipped by me too. Not to say this will fix it, but if you haven't done it (or not lately) it can really help the running condition.

Lou

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PostPosted: Tue Feb 19, 2019 8:49 pm 
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3 Deuce Webber

Joined: Mon Feb 11, 2019 9:15 am
Posts: 53
Car Model*: 1965 Dodge Dart, 225 Slant Six
Doctor Dodge wrote:
Quote:
- Valvetrain doesn't seem to be noisy...

All this carb work...

I may have missed this but... did you ever actually check the valve lash adjustment?

Tight valve lash will cause the engine to run poorly.
Pull the valve cover and confirm the the valve lash is set correctly... before doing anything else.
DD


No I didn't check it. I got the car quite recently an actually am not even sure if this car has hydraulic or solid lifters.


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PostPosted: Tue Feb 19, 2019 8:54 pm 
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3 Deuce Webber

Joined: Mon Feb 11, 2019 9:15 am
Posts: 53
Car Model*: 1965 Dodge Dart, 225 Slant Six
matv91 wrote:
http://imperialclub.org/Repair/Lit/Master/ Go here and go down to 1966 there 2 carb movies and articles

Thanks! What a great site, went straight to my bookmarks.


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PostPosted: Thu Feb 21, 2019 8:31 am 
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3 Deuce Webber

Joined: Mon Feb 11, 2019 9:15 am
Posts: 53
Car Model*: 1965 Dodge Dart, 225 Slant Six
THOR wrote:
Greetings from Oregon!

First issue that I am noticing is your "remanufactured" Holley 1920. That immediately makes me wonder what size Jet is installed in the carb. In addition, if plug 1 is lean and 6 is showing rich, I would be taking a look at plug wires and checking resistance. Typically, 1 and 6 are similar, 2 and 5 are similar, and 3 and 4 are similar.

I suggest pulling the fuel bowl, removing the brass jet carefully from the metering block, and letting us know what the 2 digit number is.

Timing wise, I typically run mine at about 12-14 BTDC. Also, your rocker arms should produce a slight ticking noise if they are properly adjusted. If you hear absolutely no noise, they are likely too tight, which will cause the idle to be rough.

~THOR~

The problem was quite simple and the answer lies in this text by THOR. I wanted to check the spark plugs because I've been messing with the jet size etc. While in there I decided to measure the spark plug wire resistances, one of them was bad (in the pic).

I bought a new one and it works like it should. I also ordered the whole set of new spark plugs and a complete set of spark plug wires, this cheap wire is just a temporary fix. Spark plug color was black so I think I'll set the float level to the spec when I install new plugs and after a while I'll check the spark plugs and if they're black I'll go back to the size 58 jet.

I feel a bit stupid for not checking the wires earlier since I was suggested to do it right from the beginning. But I'm not bummed out by this experience because I learned a lot about carburetors and got familiar with my car.

Thank you all who wrote to me and helped!


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PostPosted: Thu Feb 21, 2019 8:50 am 
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Location: Rome, GA
Car Model*: 1963 Dart 270, 1980 D150
Good job man!

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PostPosted: Fri Feb 22, 2019 11:15 am 
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Joined: Fri Feb 29, 2008 10:49 pm
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Location: Salem, Oregon
Car Model*: 58 Plymouth Plaza 2dr, 63 Valiant Signet 200 2dr
Fantastic! :D

~THOR~

_________________
1958 Plymouth Plaza 2 door Club Sedan
1963 Plymouth Valiant Signet 200 HT - "CL4P-TP"
Licensed Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing


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PostPosted: Sun Feb 24, 2019 12:03 pm 
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This is from older holley info pre dates the 1920


3. MAIN METERING SYSTEM When the engine is running, the intake stroke of each piston draws air through the carburetor. As this air passes through the venturi of the carburetor, the drop in pressure in the venturi creates what is commonly called a vacuum. The strength of that vacuum varies in proportion to the velocity of the air flow through the venturi. This, in turn, is governed by the speed and power output of the engine. At normal cruising speeds, the difference between the normal, atmospheric air pressure in the float chamber and the vacuum in the venturi is used to operate the main metering system. This pressure differential draws a metered flow of fuel from the float chamber through the main metering system and out the main nozzle into the air stream in the venturi. When the fuel passes out of the float chamber, it is metered (or measured) by the main jet as it flows into the bottom of the main well. The fuel moves up the main well past the two narrow air bleed passages and enters the main nozzle. Filtered air from the carburetor air inlet enters the air speed bleed and passing out the two narrow air bleed passages is mixed with the fuel flow in the main well. The high speed bleed meters a properly increasing amount of air into the fuel as speeds increase, stabilizing the fuel discharge and main-taining the required mixture ratios. This emulsion of fuel and air, being lighter than the raw fuel, has a more instantaneous response to any change in venturi vacuum and is more readily vaporized than raw fuel upon being discharged into the air stream. The fuel flows through the main nozzle and is sprayed onto the open choke plate in the venturi. Airstream turbulence over the distribution pin and choke plate distributes the fuel over the lower portion of the choke plate where it is vaporized and mixed with the air flowing through the carburetor. The throttle plate controls the amount of fuel-air mixture admitted to the intake manifold, regulating the engine speed and power output in accordance with accelerator pedal movement. The distribution pin extending perpendicularly from both sides of the choke plate creates a turbulence as an aid to the proper distribution of the mixture to all cylinders of IDLE SYSTEM


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PostPosted: Sun Feb 24, 2019 2:11 pm 
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I also checked the fuel level in the bowl by measuring from the economizer hole. It is kinda hard to measure it that precisely because my engine mounts are very worn and the engine shakes a bit. But from the outer surface of the economizer hole to the fuel the distance is about 26/32 inches, this is the right way to measure it, right? Yes, shut engine off then measure again. 27/32 inches puts fuel level even with top air hole. So in theory as main system starts to flow a mixture of fuel and air is in the main well. At 26/32 inches top air hole is covered by fuel. Again in theory at the start of main system flow only fuel will be in main well. How much difference this makes on a 1920 carb ? just theory


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PostPosted: Sun Feb 24, 2019 2:35 pm 
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Turbo Slant 6

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PostPosted: Sun Feb 24, 2019 2:47 pm 
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Thats older holley carb. Does not have fuel feed into main air well. Information only, this may not apply to 1920 carb.


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