Tell me more about the large orange "R" on Rochester carbs

[Mike E.]

I've seen several of these. The picture attached is of a 70 that has 62k miles and was purchased from the original owner a year ago. The picture attached is of the side of the carb before any cleaning has been done. Sorry it is not clear. Was this "R" an inspection mark? Was it on all Quadrajets before they were cleaned or rebuilt? PC151602.JPG

[Mike E.]

Re: Tell me more about the large orange "R" on Rochester carbs

Anyone with input?

[Patrick H.]

Re: Tell me more about the large orange "R" on Rochester carbs

I always thought it meant Rebuilt, but if you think the carb is original to the car then it throws that theory out the window.
It may mean repaired or similar, yet after repair it may have been good enough to reuse.

Just a thought.

[Terry M.]

Re: Tell me more about the large orange "R" on Rochester carbs

I've seen several of these. The picture attached is of a 70 that has 62k miles and was purchased from the original owner a year ago. The picture attached is of the side of the carb before any cleaning has been done. Sorry it is not clear. Was this "R" an inspection mark? Was it on all Quadrajets before they were cleaned or rebuilt? [ATTACH=CONFIG]51082[/ATTACH]

Mike,
I have seen it on every unmolested 1970 Corvette Rochester carburetor I have seen. Since I have not seen ALL of the 1970 Rocheaters, in spite of my best efforts, I can not tell you it was on ALL of them -- but I strongly believe it was.

I think it means R = Rochester, but I have nothing to support that belief. On the other hand I have recently acquired a set of AC Delco carburetor books (three of them about six inches thick each). I hope I have time to go through them in the time I have remaining.

[Joe L.]

Re: Tell me more about the large orange "R" on Rochester carbs

I've seen several of these. The picture attached is of a 70 that has 62k miles and was purchased from the original owner a year ago. The picture attached is of the side of the carb before any cleaning has been done. Sorry it is not clear. Was this "R" an inspection mark? Was it on all Quadrajets before they were cleaned or rebuilt? [ATTACH=CONFIG]51082[/ATTACH]

Mike------


I can tell you I've never seen it on a 68-69 Q-Jet and can say, for certain, that it was not on my original 1969 Q-Jet.

Was the carb pictured a Rochester Q-Jet manufactured by Carter?

[Sal C.]

Re: Tell me more about the large orange "R" on Rochester carbs

As Joe is suggesting, it may be a way to quickly to distinguish between a Carter and Rochester built Q-jet.

[Chris H.]

Re: Tell me more about the large orange "R" on Rochester carbs

Here's my "R" from my 70 LS5, VIN 531.

[David L.]

Re: Tell me more about the large orange "R" on Rochester carbs

Chris,

I assume that your carb is a Rochester Q-Jet since it has a Julian date. The Carter Q-Jet carbs all seem to have the 2-digit month & year date code.

In my collection I have a 7040203 Rochester Q-Jet dated "2619" (Sept. 18, 1969) and a 7040203 Carter Q-Jet dated "A0" (Jan. 1970). I bought both carbs at swap meets and neither has a large painted letter. I believe I have a few 7040202 carbs (for A.T. cars) somewhere as well.

Dave

[Mike E.]

Re: Tell me more about the large orange "R" on Rochester carbs

The carb I photoed is dated 0140. The car isn't here right now, but I'm almost sure that I recall that it's a Rochester-built Quadrajet.

[Terry M.]

Re: Tell me more about the large orange "R" on Rochester carbs

The carb I photoed is dated 0140. The car isn't here right now, but I'm almost sure that I recall that it's a Rochester-built Quadrajet.

With that date code it IS Rochester. As someone above mentioned, Rochester uses a year & Julian date -- Carter built Q-Jets use a letter for the month and a single number for the year.

[Mike E.]

Re: Tell me more about the large orange "R" on Rochester carbs

With that date code it IS Rochester. As someone above mentioned, Rochester uses a year & Julian date -- Carter built Q-Jets use a letter for the month and a single number for the year.

I was pretty sure about that-I know that's what the present JG says. What do you think about the "R"? 70-only?

[Joe L.]

Re: Tell me more about the large orange "R" on Rochester carbs

I was pretty sure about that-I know that's what the present JG says. What do you think about the "R"? 70-only?

Mike------


There's another possibility I thought of here. There are three main components to a Rochester carb----the air horn assembly, the float bowl assembly, and the throttle body assembly. The float bowl is the most complex and there were many different float bowls used for different applications. It might be that the "R" was a form of a broadcast code which helped ensure that Rochester assembly line workers used the right float bowl for the right application. "R" may have been the code for the float bowl used for Corvette carburetors (and, possibly, others, too).

[Terry M.]

Re: Tell me more about the large orange "R" on Rochester carbs

I was pretty sure about that-I know that's what the present JG says. What do you think about the "R"? 70-only?

I have only seen it on 1970s, but I have not done a real thorough job of researching it. I have to admit I never thought of the Rochester v Carter idea that Joe and Sal brought up, and I kept no records of what I have seen so I can offer nothing about early/late cars either. I do remember seeing it on a big block built right at or around Feb 1, but that is the only one I can remember the sn on, and that is only because that car was one of the first Torx door strikers I have noticed. I haven't seen or heard from that owner in a long time Tom Puckelwertz.