Carburetor float drop

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Corsa bill
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Carburetor float drop

Post by Corsa bill »

Can any one tell me the float drop of a 65 carb. The owners manual tells me one number and the kit I’ve got tells me another.
Also I’m assuming my secondary carburetors floats will be the same.
The book calls for a 1 1/2 drop. The kit says 13/32
Which one should I use for the float drop.

Corsa bill
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Re: Carburetor float drop

Post by Corsa bill »

Also the float laying upside down calls for a 1 1/6 measurement. Does this sound right?

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terribleted
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Re: Carburetor float drop

Post by terribleted »

Corsa bill wrote:
Sun Jun 21, 2020 12:01 pm
Also the float laying upside down calls for a 1 1/6 measurement. Does this sound right?
No the manual states in the fuel section a float level of 1 13/64” and drop of 1.5”. 1 1/16 will likely continuously flood the engine. Float drop is not that critical and is specified to keep the float from contacting the bottom of the fuel bowl all the time.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
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Corsa bill
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Re: Carburetor float drop

Post by Corsa bill »

ok, what set my Floats at is 1 1/16 level. I turn the carb upside down and measure from the gasket to the top of the float. I then turned the carb right side up and measure the drop and set it at 1 13/16.
I think I’ve got it right.
Is that right Terribled?
Thank you for getting back to me.

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terribleted
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Re: Carburetor float drop

Post by terribleted »

NO The drop is 1 1/2 set with the float hanging under the carb top. The float level is set at 1 13/64" measured from the gasket to the top of the floats with the carb top inverted on the bench. The manual specifies no measurement of 1 13/16" nor 1 1/16. You said something about 1 1/6" above which is also not any specified measurement. You need to use the factory shop manuals when doing repairs. You do not specify what year car you are working on so I can not provide links to the manual for your year. Most early model manuals are here https://www.corvair.org/chapters/corvan ... anuals.php Some late model manuals are here http://www.1969corvair.com/techpages/Co ... Index.html I really suggest you buy paper copies of the primary GM shop manual for your year group and the supplement for your specific year if there is one (61 and 65 had no supplemental manual)\
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia

Corsa bill
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Joined: Sun Feb 14, 2016 5:41 pm
Location: Placerville Ca.

Re: Carburetor float drop

Post by Corsa bill »

Ok, I’m going to the manual. This shouldn’t be this hard. My car is a 65 corsa. I was wrong stating 1 13/64. It’s 1 13/16 that’s what the instruction sheet says with the carburetor kit I bought. I’ll go with what the manual says, nothing like doing the same thing 6 times. Well at least I’ve left the screws loose on the carbs.

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terribleted
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Re: Carburetor float drop

Post by terribleted »

I have found to never trust a carb kit sheet. Also note that if you look at float level specs in the specifications section of some of the GM shop manuals they list 1 1/8" This setting leaves the float too high and likely to flood. Turbo carbs use this setting perhaps that is where the printed error occurred. Every fuel section in every GM Corvair shop manual says 1 13/64" in the rebuilding instructions. I have always used 1 7/32 which is 1/64 more (lower in operation) simply because I have a nice sliding rule that is incremented in 32's. This setting has never given me any issues. At some point making this measurement too large will not allow enough fuel to collect in the bowl. Making it shorter will increase chances of flooding as the needles valve will not have enough pressure on it (when the float is floating in a full carb) to overpower the fuel pressure and stop the flow. If the flow does not stop when the carb is full, the carb overflows fuel into the intake...flooding.

I have been rebuilding these carbs for over 30 years. I still have the manual at my side and follow the step by step carb adjustment procedures listed as I build one, even though I know the steps and measurements by heart. Every now and again the manual reminds me no to forget a step or sub step.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia

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Re: Carburetor float drop

Post by bbodie52 »

:think:
FLOAT LEVEL: 1-1/16"
FLOAT DROP: 1-13/16"

According to the specs in the attached DELCO ROCHESTER - Models H, HV Carburetor Service Guide.

For some early model years the manual says...
FLOAT LEVEL: 1-7/32"
FLOAT DROP: 1-3/4"

FLOAT LEVEL: 1-3/16"
FLOAT DROP: 1-3/4"
:confused: :fishing:


:chevy:
Attachments
DELCO ROCHESTER - Models H, HV Carburetor Service Guide.pdf
(1.79 MiB) Downloaded 5 times
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible

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terribleted
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Re: Carburetor float drop

Post by terribleted »

bbodie52 wrote:
Mon Jun 22, 2020 8:00 pm
:think:
FLOAT LEVEL: 1-1/16"
FLOAT DROP: 1-13/16"

According to the specs in the attached DELCO ROCHESTER - Models H, HV Carburetor Service Guide.

For some early model years the manual says...
FLOAT LEVEL: 1-7/32"
FLOAT DROP: 1-3/4"

FLOAT LEVEL: 1-3/16"
FLOAT DROP: 1-3/4"
:confused: :fishing:


:chevy:
OK Brad what spec should we pay attention to? the 61 main book on page 9-11 clearly states 1 13/64" float level and says 1 3/4" drop (the drop measurement shown in these manuals actually changes to 1 1/2" at the 65 model year). The 65 Gm Chassis Shop Manual says on page 6M-6 (Primary carbs) and page 6M-10 secondary carbs 1 13/64". The other supplements are the same. Any time I have seen 1 1/8 or something like 1 1/16 there have been flooding issues. I have never had starvation or any flooding using this measurement from the main manual.../shrug.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia

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bbodie52
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Re: Carburetor float drop

Post by bbodie52 »

con·sen·sus
/kənˈsensəs/

noun
a general agreement.
"a consensus view"
:think: :dontknow: :helpsos: :idea:

The Corvair Shop Manuals (1960,1961, and 1965) and the supplements for other model years often suffer from inconsistencies, internal disagreements, errors, etc. The specifications and settings in the GM publication DELCO ROCHESTER - Models H, HV Carburetor Service Manual (Bulletin 9D-6, dated Dept. 1966) — copy attached, also has some conflicts with the information published in the shop manuals and supplements. You can read the manuals and supplements and the Delco publication and then try to draw a consensus. You can listen carefully to opinions voiced on the Corvair Forum and other Corvair websites, and possibly also invest in aftermarket books written by experienced Corvair Gurus [an influential teacher or popular expert] like Bob Helt to add to the mix. Trial and error comes to mind...

...or, I might invest in Electronic Fuel Injection and give that a try!
Image :link: http://www.corvair-efi.com/


Image
:link: http://www.corvair.com/user-cgi/catalog ... w_page=245

Image :link: http://www.corvair.com/user-cgi/catalog ... w_page=248

Image :link: http://www.corvair.com/user-cgi/catalog ... w_page=246
CARBURETOR TRAINING BOOKLET
All Corvair carburetors (exc. Turbo). Originally designed for training Dealer Mechanics. 28 pictures More detailed steps and theory than in a Shop Manual.
:chevy:
Attachments
DELCO ROCHESTER - Models H, HV Carburetor Service Manual.pdf
DELCO ROCHESTER - Models H, HV Carburetor Service Manual
(1.79 MiB) Downloaded 4 times
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible

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terribleted
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Re: Carburetor float drop

Post by terribleted »

Trial and error is precisely why I always suggest staying very close what is in the basic shop manuals as these measurements have always worked for me:)
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia

Corsa bill
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Joined: Sun Feb 14, 2016 5:41 pm
Location: Placerville Ca.

Re: Carburetor float drop

Post by Corsa bill »

Well I’ve changed the floats back to a 1 1/2 float drop. I’m still have them on the bench do I could change them again but I’ll just give it a try with this setting. If I have any issues I’ll change them again. I’m gettin really good now at taking them apart and putting them back together, I’ve been smart enough to not tighten them up till I’m sure they are adjusted to the specs I want.
I’ll the pumps rubber grommets we’re toast. I’m not sure if the there was any grommet left in any of the four of them.

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terribleted
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Re: Carburetor float drop

Post by terribleted »

So what float level did you set? Level is much more relevant than drop/
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia

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