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View Full Version : correct carburetor and bell housing #'s 57 Bel Air 283, 3-speed manual


bowtie2
02-17-2013, 03:19 PM
Does anyone know the correct make and numbers of the 4 barrel carburetor and the bell housing numbers that go with/came with 1957 Bel Air 2 dr sedan, 283, w 3 speed manual (engine suffix code E)?

stoveboltgeek
02-17-2013, 05:13 PM
Carter WCFB #2555S.

57 4dr
02-17-2013, 05:57 PM
Does anyone know the correct make and numbers of the 4 barrel carburetor and the bell housing numbers that go with/came with 1957 Bel Air 2 dr sedan, 283, w 3 speed manual (engine suffix code E)?

If you want a Rochester Carb, and your 57 is a very early build, you want 7008737 and if it is a later build and you want a Rochester you want 7009846.

I assume you already have a 1957 4bbl intake manifold? If not there was only one made for the 57 Chevy, there are many date codes, but all have the same number for 57 which is 3731398. As for the bell housing, I will have to look into my charts and get back to you, unless someone else chimes in with that number.

Don57BA
02-17-2013, 06:20 PM
I was under the impression that a Rochester 7009846 is for the early 57's.
My 9846 has the date tag on it and it is dated A7 for January 7th.

stoveboltgeek
02-17-2013, 08:31 PM
I was under the impression that a Rochester 7009846 is for the early 57's.
My 9846 has the date tag on it and it is dated A7 for January 7th.

7009846 is only used on automatic cars. 7009846 were used until about March.

The 7 is the year, not day.

57 4dr
02-17-2013, 08:45 PM
From wha I understand, The 8737 was a 1956 carb for the 265. It was rejetted for the early 57's. After that the 9846 was produced (After March) and there was not another Rochester built for 57 that year. The 9846 was used on the power pack's. I do not know what carb was used in 58. If there was another Rochester used after the 9846, in 1957, I would love to know what it was.

stoveboltgeek
02-17-2013, 09:18 PM
From wha I understand, The 8737 was a 1956 carb for the 265. It was rejetted for the early 57's. After that the 9846 was produced (After March) and there was not another Rochester built for 57 that year. The 9846 was used on the power pack's. I do not know what carb was used in 58. If there was another Rochester used after the 9846, in 1957, I would love to know what it was.

Early 57 production is 7009846, late production is 7012126.

http://chevy.oldcarmanualproject.com/carb/Rochester/9C330p01.htm

57 4dr
02-18-2013, 11:32 AM
7009846 is only used on automatic cars. 7009846 were used until about March.

The 7 is the year, not day.

You were correct on the 9846 being earlier and the 2126 being later, but I am going to have to disagree on the use. Both the 7009846 and the 7012126 57 Carburetors were used in both Automatic and Manuel Transmissions. I have GM service data sheets that list carbs 7009846 and the 7012126 as Power Pack carbs with service info on how to set the idle for BOTH carbs for a Syncro-mesh transmissions and Power Glide & Turbo glide Auto Transmissions.

The service sheet also lists the 8737 as a 1956 V8 Power pack Carb. I think they did put that carb into the earliest of the 57's being built, but most likely changed the jets for the 283 engine.

stoveboltgeek
02-18-2013, 01:24 PM
You were correct on the 9846 being earlier and the 2126 being later, but I am going to have to disagree on the use. Both the 7009846 and the 7012126 57 Carburetors were used in both Automatic and Manuel Transmissions. I have GM service data sheets that list carbs 7009846 and the 7012126 as Power Pack carbs with service info on how to set the idle for BOTH carbs for a Syncro-mesh transmissions and Power Glide & Turbo glide Auto Transmissions.

The service sheet also lists the 8737 as a 1956 V8 Power pack Carb. I think they did put that carb into the earliest of the 57's being built, but most likely changed the jets for the 283 engine.

Based on my research a couple of years ago, '57 4 bbl PG cars used Rochester 4GC 7009846, 7012626 or Carter WCFB 2505S. Rochester and Carter were used interchangeably on PG on the assembly line. The stick shift cars used Carter 25555S exclusively - no 4GCs.

Here is my documentation:

http://www.55-57chevys.com/coccc/tech/57/410-2.gif indicates that Rochesters were not used on stick shift cars in 1957. Note this drawing was "redrawn and revised" on 3/25/57, and references the later 7012126.

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0289.htm does not say specifically where 4GCs were used. The United Motors Service division of GM literature from December 1957 (referenced above) indicates PG only for 4GC. http://chevy.oldcarmanualproject.com/carb/Rochester/9C330p01.htm .

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0289.htm is the parts catalog as of November 1957. Note it lists a separate Carter carburetor 2505SA for Turboglide cars.

My May 1957 parts catalog lists 2505S for both Powerglide and Turboglide. My 1962 parts catalog lists the 2505SA as service replacement carburetor for both Powerglide and Turboglide.

My original Carter documentation - found both in an old Carter catalog and an NOS Carter rebuild kit - says 2555S was for stick and 2505S was for automatics, but the 2505 could be used on a stick by readjusting the choke.

I'm at work right now (it's lunch time), so I don't have my '57 shop manual handy. But, I'm pretty certain it too lists the 4GC as used only on PG cars.

Would you post the factory documentation you have that states the 4GC was used on stick shifts in 1957? If I'm wrong, I'm happy to change my position in light of new evidence.

Big Bob
02-18-2013, 03:13 PM
Here you go,the late 56-59 bellhousing p/n is 3733365 cast iron,10.5 clutch with 168 tooth flywheel. The earlier bellhousing for 55-56 is p/n 3704922 and 10.5 clutch,168 tooth flywheel also.Hope this helps,good luck.
Big Bob:flag4::bowtier:

57 4dr
02-18-2013, 07:06 PM
Based on my research a couple of years ago, '57 4 bbl PG cars used Rochester 4GC 7009846, 7012626 or Carter WCFB 2505S. Rochester and Carter were used interchangeably on PG on the assembly line. The stick shift cars used Carter 25555S exclusively - no 4GCs.

Here is my documentation:

http://www.55-57chevys.com/coccc/tech/57/410-2.gif indicates that Rochesters were not used on stick shift cars in 1957. Note this drawing was "redrawn and revised" on 3/25/57, and references the later 7012126.

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0289.htm does not say specifically where 4GCs were used. The United Motors Service division of GM literature from December 1957 (referenced above) indicates PG only for 4GC. http://chevy.oldcarmanualproject.com/carb/Rochester/9C330p01.htm .

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0289.htm is the parts catalog as of November 1957. Note it lists a separate Carter carburetor 2505SA for Turboglide cars.

My May 1957 parts catalog lists 2505S for both Powerglide and Turboglide. My 1962 parts catalog lists the 2505SA as service replacement carburetor for both Powerglide and Turboglide.

My original Carter documentation - found both in an old Carter catalog and an NOS Carter rebuild kit - says 2555S was for stick and 2505S was for automatics, but the 2505 could be used on a stick by readjusting the choke.

I'm at work right now (it's lunch time), so I don't have my '57 shop manual handy. But, I'm pretty certain it too lists the 4GC as used only on PG cars.

Would you post the factory documentation you have that states the 4GC was used on stick shifts in 1957? If I'm wrong, I'm happy to change my position in light of new evidence.

Hi Stovebolt, I am in the start of sugaring season, and I am in the woods from sunrise to sunset tapping trees. I have several items to dig up for you showing that 7009846 and 7012126 Rochester carbs were not excusivly used on auto Transmissions. I will get back to you very soon.
Dennis

f.i.57chevynut
02-19-2013, 01:31 AM
Here you go,the late 56-59 bellhousing p/n is 3733365 cast iron,10.5 clutch with 168 tooth flywheel. The earlier bellhousing for 55-56 is p/n 3704922 and 10.5 clutch,168 tooth flywheel also.Hope this helps,good luck.
Big Bob:flag4::bowtier:

Those numbers are the casting numbers on the bellhousing. The powerpack cars in 56 and 57 used a 3 finger Borg and Beck clutch. To facilitate clutch service GM used the allen- wrench removeable fork pivot so the fork could be pulled back in the bellhousing allowing enough clearance to drop out the disc and plate together. the 55 and 56-57 2 barrel cars used a pivot ball that had a hex shouldered stud the threaded in from the clutch side. The diaphragm clutch was shorter in height and didn't need the fork to be pulled back in the bellhousing to drop out the bottom. In 58 all the bellhousings used the allen style pivot.

57 4dr
02-19-2013, 10:43 AM
Based on my research a couple of years ago, '57 4 bbl PG cars used Rochester 4GC 7009846, 7012626 or Carter WCFB 2505S. Rochester and Carter were used interchangeably on PG on the assembly line. The stick shift cars used Carter 25555S exclusively - no 4GCs.

Here is my documentation:

http://www.55-57chevys.com/coccc/tech/57/410-2.gif indicates that Rochesters were not used on stick shift cars in 1957. Note this drawing was "redrawn and revised" on 3/25/57, and references the later 7012126.

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0289.htm does not say specifically where 4GCs were used. The United Motors Service division of GM literature from December 1957 (referenced above) indicates PG only for 4GC. http://chevy.oldcarmanualproject.com/carb/Rochester/9C330p01.htm .

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0289.htm is the parts catalog as of November 1957. Note it lists a separate Carter carburetor 2505SA for Turboglide cars.

My May 1957 parts catalog lists 2505S for both Powerglide and Turboglide. My 1962 parts catalog lists the 2505SA as service replacement carburetor for both Powerglide and Turboglide.

My original Carter documentation - found both in an old Carter catalog and an NOS Carter rebuild kit - says 2555S was for stick and 2505S was for automatics, but the 2505 could be used on a stick by readjusting the choke.

I'm at work right now (it's lunch time), so I don't have my '57 shop manual handy. But, I'm pretty certain it too lists the 4GC as used only on PG cars.

Would you post the factory documentation you have that states the 4GC was used on stick shifts in 1957? If I'm wrong, I'm happy to change my position in light of new evidence.

Hi Stovebolt,

As promissed;

In the link below, page 1652 of the National Service Data Manual for Rochester Carburetors 1956-1958. You will note that the carbs listed for 1956, and 1957 make no distinction to Transmission, but it does for 1958.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=14665

In the link below, page 260 of the National Service Data Manual for Rochester 4-Barrel Carburetors 1957. Of note is that there is no distinction for transmission for Chevy.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=10322

In the link below, page 268 of the National Service Data Manual for 1957 Rochester 4 Barrel Jet Specifications. Of not once again they do not specify transmission type as in other carbs on the page.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=10330

This the link below, page 826 of the National Service Data Manual for General Motors, Chevrolet V8 Cars and Corvette 1957. Of note is the adjustment of Idle adjustment for 7009846 & 7012126 Carbs for both the Synchro-mesh (Standard Trans) and for the Powerglide & Turbglide.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=12510

In the link below, page 1668 of the National Service Data Manual for 1957-58 Rochester 4-Barrel Carburetor Jet Specifications. Of note is that in 57 the carbs are not transmission specific, but they are in 1958 for Auto Transmissions.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=14681

Also, you mentioned the 1957 Chevrolet Passenger car manual. This book was written and printed in 1956, and talks about carb 7008737 only. Carbs 7009846 and 7012126 were not even made yet.

I also own "Servicing the Rochester Four Barrel Carburetor". This Manual is "T-O-P 57-26-S&M", a "Super Chevrolet Service" Logo booklet Published "May 1957 SI-7275-3 by the Chevrolet Motor Division, General Motors Corp, Detroit Michigan. Page 2 " The Rochester four barrel carburetor is supplied with the factory installed Powerpack option on various 1956 and 1957 models, Mainly with automatic transmissions. It is also supplied in dealer-installed Powerpack units." Note the use of the word "Mainly". It does not say "exclusively used", or "only used".

In fact on page 8 you will find the directions on setting the "Idle speed and mixture". "Install the air cleaner. Warm engine until the choke valve opens. Connect Tachometer and vacuum gauges. Adjust idle speed to 425 RPM, with selector lever in "Drive" position with the parking brake applied. (450 RPM on conventional Transmissions).

If you would like, I can scan the above service booklet and send it to you via e-mail. It is only about 40 pages. I have never seen this booklet on line, I got my original copy on e-bay.

What do you think? I say they did use these carbs on standard Transmissions.
Dennis

57 4dr
02-19-2013, 04:08 PM
Does anyone know the correct make and numbers of the 4 barrel carburetor and the bell housing numbers that go with/came with 1957 Bel Air 2 dr sedan, 283, w 3 speed manual (engine suffix code E)?

Bowtie2, I did not wish to hijack your thread, and I hope your questions were answered? Your question was great, and I think it caused a lot of deep research, conversation and thought on the Carbs to use. Did all your questions get answered, and did it raise any other questions?

stoveboltgeek
02-19-2013, 06:23 PM
Hi Stovebolt,

As promissed;

In the link below, page 1652 of the National Service Data Manual for Rochester Carburetors 1956-1958. You will note that the carbs listed for 1956, and 1957 make no distinction to Transmission, but it does for 1958.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=14665

In the link below, page 260 of the National Service Data Manual for Rochester 4-Barrel Carburetors 1957. Of note is that there is no distinction for transmission for Chevy.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=10322

In the link below, page 268 of the National Service Data Manual for 1957 Rochester 4 Barrel Jet Specifications. Of not once again they do not specify transmission type as in other carbs on the page.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=10330

This the link below, page 826 of the National Service Data Manual for General Motors, Chevrolet V8 Cars and Corvette 1957. Of note is the adjustment of Idle adjustment for 7009846 & 7012126 Carbs for both the Synchro-mesh (Standard Trans) and for the Powerglide & Turbglide.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=12510

In the link below, page 1668 of the National Service Data Manual for 1957-58 Rochester 4-Barrel Carburetor Jet Specifications. Of note is that in 57 the carbs are not transmission specific, but they are in 1958 for Auto Transmissions.

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=14681

Also, you mentioned the 1957 Chevrolet Passenger car manual. This book was written and printed in 1956, and talks about carb 7008737 only. Carbs 7009846 and 7012126 were not even made yet.

I also own "Servicing the Rochester Four Barrel Carburetor". This Manual is "T-O-P 57-26-S&M", a "Super Chevrolet Service" Logo booklet Published "May 1957 SI-7275-3 by the Chevrolet Motor Division, General Motors Corp, Detroit Michigan. Page 2 " The Rochester four barrel carburetor is supplied with the factory installed Powerpack option on various 1956 and 1957 models, Mainly with automatic transmissions. It is also supplied in dealer-installed Powerpack units." Note the use of the word "Mainly". It does not say "exclusively used", or "only used".

In fact on page 8 you will find the directions on setting the "Idle speed and mixture". "Install the air cleaner. Warm engine until the choke valve opens. Connect Tachometer and vacuum gauges. Adjust idle speed to 425 RPM, with selector lever in "Drive" position with the parking brake applied. (450 RPM on conventional Transmissions).

If you would like, I can scan the above service booklet and send it to you via e-mail. It is only about 40 pages. I have never seen this booklet on line, I got my original copy on e-bay.

What do you think? I say they did use these carbs on standard Transmissions.
Dennis

I'm sorry, Dennis - my mind is made up, so don't confuse me with the facts. :sign0020:

What the heck IS this thing? I have never seen it before. Is it published by GM or an "aftermarket" company? It looks GM-ish, but like I said - I've never seen it before.

Page 826 is strong evidence in favor of 4GCs being used on manual transmissions - or at least that it was planned to do so. Also, it discusses both early and late '57 4GCs, so it clearly isn't a pre-production document.

Page 1652 is also interesting, as it covers '58 as well as '57. If page 826 was preliminary '57 data, it could be argued that 4GC use was planned but not actually implemented. The fact that 1652 does not say "automatic only" (like it does for '58) lends credibility to 826.

(BTW - I think "planned but not actually implemented" is what actually happened with 4 speeds in '57 passenger cars. There was an announcement of it in the Chevrolet Service News around April or May 1957, but no GM parts catalogs list 4 speed parts for '57 passenger cars - only '57 Corvettes and '58 passenger cars. It's a perfect example of a documentation discrepancy.)

Then, of course, there's TOP 57-26. I too have this book, but usually use the online copy http://chevy.oldcarmanualproject.com/booklets/5726topindex.htm . As far as pages 2 and 8, well - you're right. Hmm...how am I going to talk my way out of this one? :) I've already discussed "planned but not implemented"...

"It is also supplied in dealer installed Powerpak units" is an important clue as well. Of course, we have "factory authorized and dealer installed", "dealer installed without factory authorization", and "factory installed" - each of which are very different. The assembly drawing and Rochester bulletin appear to focus on factory installed.

Your book's data and TOP 57-26 clearly conflict with the 4 bbl assembly drawing and Rochester bulletin I cited. So - which ones are right?

The assembly drawing was redrawn in March. The previous version was undoubtedly destroyed, so we have no way of knowing if it specified 7009846 as optional for early production stick shift. If it did, your book is right, the Rochester bulletin I cited is wrong, and the assembly drawing we have simply reflects late-production usage.

Or, it's possible that 4GC stick shift use was planned but not implemented, and your book's editors didn't catch the mistake. (Remember that humans had to review this data - no computer databases to automatically perform data integrity checks.) In that case, the assembly drawing and Rochester bulletin would be right.

As you mentioned - the '57 shop manual is pre-production (or very early production). And, I have found errors in the shop manual. One of the more embarassing places is in the ignition section, where spark plug wires are mis-numbered. Oops. :)

I'd like to see some more information (title page, etc.) on your book.

I may need to change my stance from "no 4GCs on stick shifts" to "it appears we have conflicting data on the subject".