Topic: 66 T Code Thermactor Backfire number stamped

[Josep]

Hello, can anybody put some light on what this numbers means..?

I6 anti-backfire valve body stamped: C6DE-C L 3555

Thanks,

Josep

[J_Speegle]

Just a supplier code identifying the part number for their in house purposes. All these valves had that or one of the other numbers depending on what the design/model was


To the right of that you may find a stamped date code

[Josep]

Thanks Jeff.!
Did find 841 for date code, and I checked for 8A1 but definitely is 841, any sense..?

Thanks,

Josep

[Josep]

Hello,

I'm asking for the date code of this part in case it's a date code.
Part in question is the anti-backfire valve coming from a 66 SJ Thermactor system.
On the side we can read C6DE C-L 3555 841 What's this 841 means..? It's not 8A1 which I can understand,
but such number is new to me. On the picture attached shows something like 850 or 851, any help.?

[Josep]

Could be but I really do not agree with that. I have seen 3 different valves and all 3 starts with 8.
Could be that all those 3 valves are from 68..? Hmmmm I don't think so.. but we'll see..

Josep

[J_Speegle]

Could be but I really do not agree with that. I have seen 3 different valves and all 3 starts with 8.
Could be that all those 3 valves are from 68..? Hmmmm I don't think so.. but we'll see..

Considering they made possibly millions of these valves you might just have gotten "lucky" and from all the same period. Consider that there are also a fair number of service replacements made into the 70's and possibly into the 80's out there in boxes and on cars. Since the applications for Ford for these valves stopped in 67 I believe its not a streach that they would produce a fair number for repair and replacement purposes in 1968 if that is indeed what the coding is.

Without going out and digging out a handful of valves and posting all the numbers found - maybe latter - the couple I have pictures of show two patterns - one with just the number system as you have (in fact another starting with and another that used letters and numbers (3FD in this example)

Now I can't tell from looking at the pictures if they are from different suppliers (which could explain the different in house coding practice) - we have seen service replacements identified from Carter and from Holley.  Or it could be different coding for different time periods. Not enough information to base anything on at this point that I know of

[Josep]

I've been told that this is a date code used by Holley in the 60s and early 70s, but my valve has the FoMoCo brand stamped on the top.!

What are the numbers you already have Jeff..?

Thanks,

Josep

[jstefanick]

How about this theory for your 841 code, taken from another Mustang decoding website, that this valve was made by Holley, 8 is for 1968, 4 is for April, 1 is for the first week of April 1968. Take a look at this site, about halfway down, Holley carb date decode, could be the same for a Antibackfire valve made by them?  http://www.mustangtek.com/FordDateDecoding.html

Here is a pic of my AntiBackfire valve code, mine is installed on the car, so tough to get a pic, but mine is somewhat different, C6DE-9B289-CL3555.

This one on eBay has a similar part number, but not the 9B289 part of the code, it appears to be a service part.

I believe all the Thermactor related parts were in the 9Bxxx engineering number group part of the code.

http://www.ebay.com/itm/NOS-Smog-Valve-66-67-Ford-Mustang-Fairlane-Falcon-Bronco-4x4-Econoline-170-200-/401188214444?vxp=mtr

[Josep]

You're more than right jstefanick, 841 corresponds to 1968 April 1st week as seen in the link you've provided.
My backfire valve has the following numbers;
C6DE C L3555 841, so assume that was a replacement part due to damage or breakage in the original.
It's fine for me, just wanted to know what those numbers mean.!
Thanks very much.!

Josep

[J_Speegle]

How about this theory for your 841 code, taken from another Mustang decoding website, that this valve was made by Holley, 8 is for 1968, 4 is for April, 1 is for the first week of April 1968. Take a look at this site, about halfway down, Holley carb date decode, could be the same for a Antibackfire valve made by them? 

Would make sense that Holley would use their dating pattern on parts they made, for internal tracking and Carter would use theirs. That would explain the other style dating we see on the others

WIll include the dating of these valves next time I up date the Article (where the Holley and Carter date patterns is shown presently) 

[Josep]

This one on eBay has a similar part number, but not the 9B289 part of the code, it appears to be a service part.
http://www.ebay.com/itm/NOS-Smog-Valve-66-67-Ford-Mustang-Fairlane-Falcon-Bronco-4x4-Econoline-170-200-/401188214444?vxp=mtr

Just reviewing the part again and I notice that numbers casted on valve doesn't match with what states in the box. Box says C6DZ 9B298 B and valve is C6DE - C L -3555 and I believe there's a number at the far right, but I can't read it.
Just guessing...could be that valves marked with 9B289 etc.. would be for Ford parts reference and C-L 3555 or any other number would be for Holley or Carter reference part numbers...?
How do you identify it's a Holley or Carter valve..?

Josep

[J_Speegle]

Just reviewing the part again and I notice that numbers casted on valve doesn't match with what states in the box. Box says C6DZ 9B298 B and valve is C6DE - C L -3555 and I believe there's a number at the far right, but I can't read it.
Just guessing...could be that valves marked with 9B289 etc.. would be for Ford parts reference and C-L 3555 or any other number would be for Holley or Carter reference part numbers...?

Remember that you have the Ford part number (one used to inventory and order from), sometimes a supplier number and Ford engineering (one that is on the part)

Believe you'll find that the "C" in your "C-L 3555' above is the last letter in the Ford engineering number

How do you identify it's a Holley or Carter valve..?

If they are factory or though Ford originally I think we're (for the moment) thinking it comes down to the date code if the part has one. Seems that there are plenty of later service parts out there. This might be due to poor doagnostic skill and knowledge of the system in the service bays. Replacing parts rather than doing other things.  This would explain some of the booklets Ford put out to educate trouble shooting and other related tasks for these systems in the first two years.

[J_Speegle]

To add to the discussion looked in a 67 MPC and offer the following (Mustang applications only shown)

9B289 Valve assembly - Anti Back fire

66/67 - 170 & 200 Except intake manifold type C6DZ - 9B289-B
66/67 - 289 Except intake manifold type C6AZ - 9B289-E


Grabbed some used ones from the parts - don't know if these came on 66 or 67's  but appear to be 67s since there are no early dates

The variations produced with mixing in all the service replacements and multiple suppliers seem to add to the confusion at figuring out this sort of thing But I think we're getting there. Would like to see a few 1966 dated ones to complete the exercise. Lookign at two and three port versions to increase the available data points for review and consideration


First - what an over the counter service replacement top looked like during some later year - not from the factory. Don't recall seeing a Carter marked this way





Two port - C6AE-9B289-E

Marked with short engineering number, makers code and a date of 712 So possibly/likely an original from a 1967 Mustang





Marked with LONG engineering number, makers code and no date. Could this be an early 66 version or some odd ball later service replacement?





Marked with NO engineering number, only makers code and a date of 3HB. Ford oval on top/Lid. Would guess service replacement made in 1973 or possibly 1983





Three port - C6AE-9B289-E

Marked with short engineering number, makers code and a date of 736 Likely an original for a 67 Mustang/Shelby




Marked with short engineering number, makers code and a date of 854

[Josep]

Hi Jeff, many thanks for the great information you've provided.!
Notice that some markers says C6AE but is referred to C6OE, (first in the three port), are they different reference numbers for the same part..?

Josep

[J_Speegle]

Hi Jeff, many thanks for the great information you've provided.!
Notice that some markers says C6AE but is referred to C6OE, (first in the three port), are they different reference numbers for the same part..?

Last three (with the three ports) are a different part than the first set (all two ports) so they are stamped with C6OE - C (three port) rather than the C6AE- E