65 corvette original fuel pump identification

[Loren L.]

Re: 65 corvette original fuel pump identification

Loren,
is that pump a rebuildable unit that is screwed together, or like the later units crimped for life?

Joe is correct, again. Perhaps it would help a lot if it is pointed out that the recent Restorer article on these pumps used a 197? pump as its basis.

[David L.]

Re: 65 corvette original fuel pump identification

Dave, I talked to the AC SP fuel pump engineer (in this c2 c3 era) today...

Ron,

What did you talk about? Did he work for AC in the 1960's?

Dave

[Ronald L.]

Re: 65 corvette original fuel pump identification

Yes.

His idea was the rebuildable type had one set of codes and the unitized another, I sent him a couple of pictures, 65 396 66 427 pumps.

I could use some of your date from 67--70? when the date code went to three.

And in that time frame I recall there was a low mileage C3 that did not fit your theory - if the pump was original - as the owner felt it was.

By the mid 70's all the pumps were unitized.

[Joe L.]

Re: 65 corvette original fuel pump identification

Yes.



By the mid 70's all the pumps were unitized.

Ronald-----


If you're talking about fuel pumps used in PRODUCTION, after about 1966 all pumps were of the crimped, non-rebuildable style.

If you're talking about SERVICE fuel pumps, the screw-type, rebuildable pumps for 1966 and older applications have been available continuously and right up to the present.

I know of no case in which a crimped type pump replaced a screw type pump for SERVICE of an application originally using a screw type pump. Of course, a crimped type pump can be installed and used on any 55+ small block but such pumps are not GM-cataloged replacements for original pumps.

[David L.]

Re: 65 corvette original fuel pump identification

Yes.

I could use some of your date from 67--70?

Ron,

Is this a question to me? Use whatever is necessary.

Dave

[Ronald L.]

Re: 65 corvette original fuel pump identification

Dave,


I only had a couple of data points pictures of pumps, etc for the mid 60's was thinking it would be good have a matrix of this, especially in the time the coding switched to 3 digits.

[Loren L.]

Re: 65 corvette original fuel pump identification

Loren,
is that pump a rebuildable unit that is screwed together, or like the later units crimped for life?

It is screwed together; if not, I would not be able to tell you the internal date code.

[David L.]

Re: 65 corvette original fuel pump identification

I know of no case in which a crimped type pump replaced a screw type pump for SERVICE of an application originally using a screw type pump.

Joe,

I know of one case.

The 59-63 Chevrolet (283) used a "4701" screw type pump (GM # 5621682 in 63 parts catalog).
GM # 5621682 was replaced by GM # 6415047* (a "6942" screw type pump) in March 1964 which was then replaced with GM # 6415824 (AC 40254), a crimped type pump in July 1966.

I know this because many years ago I bought a NOS AC 40254 pump (GM # 6415824) stamped "008R40510" ("008R = the 8th day of 1976, I believe). Buying the pump turned out to be a mistake but that's how we learn sometimes.

Dave

* as noted in the parts catalog "When installing part 6415047 it will be necessary to rework the fuel line from the pump to the carburetor."
I have a "6942 GF" pump ("GF" = July 1966) in my collection.

[David L.]

Re: 65 corvette original fuel pump identification

Ron,

I am currently compiling a list of AC crimped type fuel pumps (1967 and newer) with stampings and the source of the fuel pump (if available). There are quite a few on the Nasty Z28 website (most are from very original 1970 Z28's) where anyone can look.

After that I will do a list of the screw-type AC pumps.

I hope that I am not just wasting my time. After I finish if there is anyone that does not believe that AC pumps have a stamped date code then they should take a course at any college about LOGIC.

Dave

[David L.]

Re: 65 corvette original fuel pump identification

Dave,


I only had a couple of data points pictures of pumps, etc for the mid 60's was thinking it would be good have a matrix of this, especially in the time the coding switched to 3 digits.

Ron,

I started a new thread this morning, "AC fuel pump date code research data".

Dave

[Scott S.]

Re: 65 corvette original fuel pump identification

Perhaps it would help a lot if it is pointed out that the recent Restorer article on these pumps used a 197? pump as its basis.

Loren,

How is an original 1965 6440083 fuel pump distinguished from a 1966 (if different), and/or how is 1965-66 different from later service replacements?

Do you have pictures of your fuel pump?

[David L.]

Re: 65 corvette original fuel pump identification

Scott,

I had a couple of 40083 pumps back in the 1990's. I sketched them before I sold them.

One of them was stamped "40083" on the flange. The base was a stamped metal plate (yellow/bronze color) attached with 4 screws. Over the years I have seen other "40083" pumps with cast bases. Photo on left is of the top view of this pump. Note the 3 ribs.

The other one was stamped "40083 IJ" (dated Sept. 1970). This pump had a stamped steel base. Photo on right is of the bottom view of this pump.

Dave

[Alan D.]

Re: 65 corvette original fuel pump identification

And some more visual help see FuelPumpRestored3.jpg

Original from Mar64 car.

[David L.]

Re: 65 corvette original fuel pump identification

And some more visual help see FuelPumpRestored3.jpg

Original from Mar64 car.

Alan,

I notice that your original "40083" pump only has one rib at the front and one rib at the back (on top at the flange), an "early" version, I assume. The "40083" pump that I once owned had 2 ribs at the front as shown in my sketch (photo on left). Your base is also the stamped steel type, like mine. I have seen cast bases on "40083" pumps at swap meets over the years. I always assumed that the cast bases were on the "early" pumps but maybe not.

Dave

[Alan D.]

Re: 65 corvette original fuel pump identification

Hi Dave, the pump shown does have the 2 ribs & the second as per your sketch. The date code inside is 64. Then the other one I have is a 67 date build again with the same details as your sketch. Have lots of pictures, email if you would like some more. See FuelPumpMid1.jpg

I purchased the car in August 1967 and that pump was on it then. Know the 2nd owner (spring 66 - August 67) and what he replaced, not the pump. Then the first owner who ordered car also said pump was not replaced, he's a current NCRS member with a beautiful green BB coupe.
So my confidence is high on the pump being original.

Know when I first had car judged, 2007, one of the top engine guys felt only the cast base was real however as time went on more credible information came out to confirm the stamped bottom was also used.