CRG Discussion Forum

Camaro Research Group Discussion => Decoding/Numbers => Topic started by: Northstar on July 30, 2008, 04:02:11 PM

Title: Q-Jet Date Codes
Post by: Northstar on July 30, 2008, 04:02:11 PM
I have been looking for a Q-Jet carb for my '69 Camaro.  I have been looking for a 7029202 model.  Some of the carbs have the julian calendar date coding (e.g. 1249 = 124th day of '69), some have a letter number code (e.g. A9= January of '69) and some apparently have no date code.  Where all of the above date coding versions used on 1969 Camaros?  What is the correct date coding information that I should be looking for?
Title: Re: Q-Jet Date Codes
Post by: crobjones2 on July 30, 2008, 04:15:30 PM
Take a look at this link
http://www.camaros.org/carb.shtml

If you have the Protect-o-Plate, it will tell you if you need either a Carter or a Rochester carb

A Carter Q used the Alphanumeric date code i.e A9
A Rochester Q used the Julian date
Title: Re: Q-Jet Date Codes
Post by: Northstar on July 31, 2008, 10:52:57 AM
I have contacted several sellers of 7029202 Q-jet carbs that claim there is no date code on the carb.  They do say that there is a double letter code like"DH" near/after the model number but no date code.  Does anyone know what the story is there?
Title: Re: Q-Jet Date Codes
Post by: bertfam on July 31, 2008, 05:02:52 PM
They all had date codes, but after many years (and several rebuildings), a lot have been sandblasted or ground off. Not so much for the ones with the dates on the bodies, but for sure on the ones with the dates on the base plate. If they use a jewlers loop, they might still be able to see the code.

Ed
Title: Re: Q-Jet Date Codes
Post by: opelitis1 on August 01, 2008, 10:23:30 AM
Bertfam is correct.. I have 2 in front of me with the 2 Alphae followed by 2 different Julian date codes...   If you'd like a pic.  let me know and I'll PM....   Ted
Title: Re: Q-Jet Date Codes
Post by: Camaro Billy on August 01, 2008, 07:01:12 PM
Here is ashot of the part number and date code on my 202 carb. I understand that the Julian date 0169 decodes as the 16th day of 1969.
Billy
Title: Re: Q-Jet Date Codes
Post by: Marty on August 01, 2008, 11:10:46 PM
If you have a Rochester built carb with the date code on the baseplate and the baseplate is replaced, you can loose the date code.

Martin
Title: Re: Q-Jet Date Codes
Post by: MyRed67 on November 03, 2010, 04:09:29 AM
I am also looking at a couple of #7029202 DH carbs. ,  the date supposedly is on the base plate.  One is 032   2,  the other is 2   22G.  I'm assuming the first is julian date 032 or 1 st. of Feb., what's the extra 2?   The second I'm assuming the date 22G is the 22 nd. of July, again, what's that first 2 for?  Thanks for any help!
Title: Re: Q-Jet Date Codes
Post by: opelitis1 on November 05, 2010, 10:29:43 AM
Why are some carbs punched 29202 and others 7029202 especially for year 1969?
What does a GM Line code or customer coding signify ?   
Title: Re: Q-Jet Date Codes
Post by: jeff68 on November 05, 2010, 12:41:19 PM
I have contacted several sellers of 7029202 Q-jet carbs that claim there is no date code on the carb.  They do say that there is a double letter code like"DH" near/after the model number but no date code.  Does anyone know what the story is there?
The letters are the plant code.
Title: Re: Q-Jet Date Codes
Post by: IZRSSS on November 05, 2010, 01:37:50 PM
I have been looking for a Q-Jet carb for my '69 Camaro.  I have been looking for a 7029202 model.  Some of the carbs have the julian calendar date coding (e.g. 1249 = 124th day of '69), some have a letter number code (e.g. A9= January of '69) and some apparently have no date code.  Where all of the above date coding versions used on 1969 Camaros?  What is the correct date coding information that I should be looking for?

7029202= Carter ID#
L8= Month & year (Dec. 68)

Earlier Carter Carbs had the date stamped on the base plate. It is located on the back left hand corner (driver side). These are the only two date code locations for a '68 or '69 Carter.
                                
Its all right here.        http://www.camaros.org/carb.shtml
 
Title: Re: Q-Jet Date Codes
Post by: bertfam on November 05, 2010, 04:17:18 PM
For the most part (and this ISN'T a hard and fast rule), all 1967 and very early 1968 production Q-jets will be in the two digit (letter/number) format. (For example, C7 would be March, 1967.)

For 1968 and early 1969 production, Q-jet date codes will be in the four digit (Julian code) format. (For example, 0339 would be February 2nd, 1969.)

Later 1969 Q-jets will have either the two digit code (if it was built by Carter), or the four digit code (if it was built by Rochester).

Again though, exceptions to the above have been observed in numberous carburetors, so you can't always go by these "rules". Also note that after many, MANY years of rebuilds, parts have been replaced and exchanged with other carburetors, so the body you have may not necessarily be attached to its original base plate.

Ed
Title: Re: Q-Jet Date Codes
Post by: crobjones2 on November 05, 2010, 07:51:32 PM
Ed
Is there a specific date in 1969 in which the q-jet changed from a julian to an alpha-numeric date code?
Title: Re: Q-Jet Date Codes
Post by: bertfam on November 06, 2010, 03:42:12 AM
I couldn't get enough data to pin it down to an exact date, but I suspect it occured early in 1969. Maybe January?

Sorry I can't be more specific.

Ed
Title: Re: Q-Jet Date Codes
Post by: opelitis1 on November 07, 2010, 01:21:08 AM
Gotta ask Q again.. Why are there some 29202 carbs and why are there some 702902 carbs.. I have 2 of the 29202 variety and the date and customer codes are DH 086 9
and the other is DH 098 9  ..  Have another carb for 1969 but this time it is Oldsmobile and the number is 29251 RJ 114 9 ..  Something must've happened in '69 or thereabouts as the carbs that I have dropped the "70" . question is why? ?
Went on and on re. the Olds carb as it has the line code and correct Julian date to be a real 1969 H/O Rochester.  Hard to either prove or dis-prove this fact, but again it was because of something that happened in a specific time frame in 1969 making Rochester drop the first 2 numerics of the carbs.. Happened sooo long ago and maybe records were not kept updated or whatever???
T.
T
Title: Re: Q-Jet Date Codes
Post by: bertfam on November 07, 2010, 02:28:58 AM
70 = Rochester products division and since it's not really needed, some carbs were produced without it.

Ed
Title: Re: Q-Jet Date Codes
Post by: crobjones2 on November 07, 2010, 02:54:25 AM
Begs the question - if 70 is a rochester plant code, why do the Carter manufactured carbs contain the 70?
Title: Re: Q-Jet Date Codes
Post by: bertfam on November 07, 2010, 03:55:18 AM
Carter was commissioned to produce the Rochester Q-Jet as a secondary source and therefore they would have the same ID markings.
Title: Re: Q-Jet Date Codes
Post by: Boston14 on November 07, 2010, 04:24:19 AM
Here's a picture of my early 69 carb number.  The car is an RS/SS 350 (L48 w/M38) built in Norwood with an 11D (1968) Fisher body date. The carb was manufactured by Carter under license from Rochester. The date is L8 which translates to NOVEMBER 1968. GM parts with stamped date codes do not use the letter i therefore L is for November (L is December for cast parts).

boston14
Title: Re: Q-Jet Date Codes
Post by: IZRSSS on November 07, 2010, 12:43:01 PM
Boston14,

Our cars were built around the same time and are both L48's. What is your cars build date? Mine is 12A (Van Nuys). Can you also elaborate on your last two sentences...I don't really follow the L part?
Title: Re: Q-Jet Date Codes
Post by: Boston14 on November 07, 2010, 03:03:54 PM
GM parts with date codes applied after manufacture (carbs, alternators, starters, etc.), if they have a date code using letters for the month, are as follows; JAN = A, FEB = B, MAR = C, APR = D, MAY = E, JUN = F, JUL = G, AUG = H, SEP = J, OCT = K, NOV = L, DEC = M.  The letter I is NOT used.  GM parts with the date codes cast in them at manufacture (engine blocks, heads, intake manifolds, etc.), if they have a date codes using letters for the month, are as follows; JAN = A, FEB = B, MAR = C, APR = D, MAY = E, JUN = F, JUL = G, AUG = H, SEP = I, OCT = J, NOV = K, DEC = L.  Hope this helps.  My build date is 11D (Norwood).

boston14
Title: Re: Q-Jet Date Codes
Post by: JohnZ on November 07, 2010, 05:51:13 PM
Can you also elaborate on your last two sentences...I don't really follow the L part?

It's discussed here:

http://www.camaros.org/forum/index.php?topic=7276.0
Title: Re: Q-Jet Date Codes
Post by: IZRSSS on November 07, 2010, 07:57:01 PM
Boston14 & John,
You had lost me with the I. Amazing...why the heck would they leave out the I. Makes no sense at all. You'd think they would have found a better way to distinguish between manufacture and post manufacture. Thanks for going to the trouble of printing it out. Now this senseless method makes sense.

Our cars were only days apart on build...cool.
Title: Re: Q-Jet Date Codes
Post by: Mark on November 07, 2010, 08:11:34 PM
Its an engineering thing.  Letters I's and O's can be confused with numbers 1 and 0, so they are not typically used when using letters to identify components where letters and numbers are used together.
Title: Re: Q-Jet Date Codes
Post by: IZRSSS on November 07, 2010, 09:26:55 PM
Now it makes perfect sense.

Thanks Mark
Title: Re: Q-Jet Date Codes
Post by: crobjones2 on November 07, 2010, 11:39:20 PM
Here's a picture of my early 69 carb number.  The car is an RS/SS 350 (L48 w/M38) built in Norwood with an 11D (1968) Fisher body date. The carb was manufactured by Carter under license from Rochester. The date is L8 which translates to NOVEMBER 1968. GM parts with stamped date codes do not use the letter i therefore L is for November (L is December for cast parts).

boston14


Looks just like mine ( except yours seems to be a little more golden in color) made E9