63 Fuel Pump

[Jon R.]

Re: 63 Fuel Pump

Doug,

Interesting photos! Not to add to the confusion, but there appear to be 2 different size "AC"s on the top of the casting. Your 'regular' pump has the smaller "AC" and your 'frog pad' pump has the larger "AC". My 'frog pad' pump matches your regular pump with the smaller "AC".

Also as you stated, your 'regular' pump has the '4657' upside down and larger than your 'frog pad' pump. My 'frog pad' also appears to match your 'regular' in this regard!

It appears that there are at least three different '63 castings......

Jon

[Frederick W.]

Re: 63 Fuel Pump

My 63 is a mid May build very close to Jon Rubel's car, his is 15193 and mine is 15054.
My pump is a frog pad like his, so perhaps it will be correct after all.

[Bob J.]

Re: 63 Fuel Pump

Bob,

The fuel pump is on the car. I took the picture with the camera between the radiator and the pump facing the rear of the car from the bottom side. So, I guess that would be the bottom front flange? The attached photo is the one that I cut the date 'hole' detail image and the number detail image from. It also shows more detail of the front lower side of the pump.

Does this help?

Jon

Clarification - the picture is upside down!

Jon,
yes that will do just fine. You take nice pics !
I would not change it but your pump does not follow the norm for 63 pumps in the stamp size or location. Later 63 pumps have been seen without the pads.
Since all three sections are simply screwed together, any conbination is possible.
Your pump has the correct looking rocker pin but the pics don't show if it has a stapled diaphragm (original). One picture shows what looks like a plated assembly screw which usually is seen blackened. Its really hard to say without seeing it in person or off the car.
Your car sounds like a very nice car, so I agree with others as to not changing things,Bob

[Jon R.]

Re: 63 Fuel Pump

Hello Harry, Bob, Doug and Frederick,

Thanks for the comments. I will be leaving it as is.

Bob,

What is a stapled diaphragm? That is another new one on me!

Maybe some other 'late' '63 owners will respond with their fuel pump details....

Regards,

Jon

[Harry S.]

Re: 63 Fuel Pump

Some photos of a new in the box 4657 dated January, 1964.

[Jon R.]

Re: 63 Fuel Pump

Bob,

Attached is a photo of the fuel pump from the bottom. The screws (except the two in holding the center cover) do appear to be blackened. The diaphram is shown - is it 'stapled'? It does appear similar to the one that Harry has shown.

Thanks,

Jon

[David L.]

Re: 63 Fuel Pump

Sorry, I need to disagree with the GF as a date.

Harry,

Have you seen the thread that I started entitled "AC fuel pump date code research data". Based on my research I would say that the "GF" represents July 1966 but that is just my opinion.

Dave

[Ronald L.]

Re: 63 Fuel Pump

To those that choose to disbelieve, one thing I did last week was talk directly to the AC fuel pump engineer for these things - they were dated, not 63, but as Dave's reseach has shown, """starting"""" in '65 they """"""Started""""" dating pumps. By the time all the rebuildable pumps went by-by for the non rebuildable kind, dating was SOP. Only things open on the question list are when did they stop 2 letter or 1 letter 1 number for the the "up to 3 numbers 1 letter system and if that transition was seamless.

You will find, as a general trend that AC products had dates on the boxes in the 60's up, and by the mid 60's most GM parts had dates on the parts themselves of one type or another.

[Jon R.]

Re: 63 Fuel Pump

Ronald,

I do not believe or disbelieve the fuel pump dating issue, I am just trying to understand and learn about the AC pump that is on my 1963 car. My question is this: If the 1963 AC fuel pumps were not dated, how do you explain the "63" in the recessed hole on my fuel pump and Jeff's fuel pump as well as the "64" in the recessed hole on Harry's pump? These 3 examples are shown in this thread.

I am the first to admit that I not an expert on Corvettes, I have only owned my car (my first Corvette) for a little over a year. I appreciate the experience and knowledge of those that have decades of involvement with these cars and am trying to take advantage of that experience and learn some of the minutia that is not available in the books.

Regards,

Jon

[Ronald L.]

Re: 63 Fuel Pump

Jon,
The statement wasn't directed your way, its clear you are trying to learn about your car. Dave is the best resource for data on the pre 66 2-piece pumps with casting dates inside.

My focus will continue to be the dating methodology used by ACSP for the 'unitised' pumps, where the date stamping was done during the assembly operations.

[Bob J.]

Re: 63 Fuel Pump

Bob,

Attached is a photo of the fuel pump from the bottom. The screws (except the two in holding the center cover) do appear to be blackened. The diaphram is shown - is it 'stapled'? It does appear similar to the one that Harry has shown.

Thanks,

Jon

Hi Jon,
really hard to tell from the pic.
I'm putting a pic on that shows the tab / staple so you can see if your pump has it.Bob

[Gerald L.]

Re: 63 Fuel Pump

So what do I have ... not original to a late April 63 car .... large font "4657", no subscript, frogpads, and nothing in the hole that I can identify as a number. Service replacement?

[David L.]

Re: 63 Fuel Pump

So what do I have ... not original to a late April 63 car .... large font "4657", no subscript, frogpads, and nothing in the hole that I can identify as a number. Service replacement?

I believe that the 4657 pump was used as early as 1958 on passenger cars. I don't think that the early 4657 pumps had the 2-digit casting year w/hash marks but I'm not 100% sure.

[Andy C.]

Re: 63 Fuel Pump

What Is The Correct Gm Part Number For Hi Performance Engine...

Hello; I would like to put my 2 cents in on the 63 Fuel pumps. I have been restoring them for some 20 years and have had quite a few. Base on what i know every #4657 AC pump made before March of 1963 did not have the 2 frog pads on the top casting. I have 3 pumps dated march and april of 63 that i took apart and rebuilt and they all have the pads. All #4657 pumps made in 63 and 64 only had the #4657 on the flange. I have seen the number stamped on the bottom as well as the top of the flange. I have seen 2 different size fonts used to stamp the 4657 number. All 3 castings are date coded! The bottom cover has the date code on the inside, the center section has the date code on the bottom of the hole by the fuel inlet. The top casting has the date on the inside at the top of the tower. Original main diaphrams have a tab that sticks out with a staple in it. the bottom diaphram has white or yellow zig-zag lines on it. The original screws are Black Oxide with the letter S on the heads. The 2 bottom cover screws have captured lock washers and mauy be Zinc or black plated.

[Jon R.]

Re: 63 Fuel Pump

Andy,

Thanks for your input. Based on your info and the remainder of the info in this thread, I conclude that the fuel pump on my mid-May car is original:

1) '4657' only (no suffix) stamped on the flange,
2) the two 'frog pads' for a later/post March pump,
3) the '63' in the hole in the middle casting,
4) the main diaphram has the tab with the staple - actually visible just behind the front pump mounting screw into the engine block in the photo attachment in post #36 above,
5) black oxide screws (can't see the letter "S" - must be really small!)
6) bottom diaphram has the white zig-zag lines
7) bottom cover screws appear to be zinc plated (can't see the captured washer)

Until I have to rebuild my fuel pump, I will not know what the two interior dates are. However, I will try to verify the letter "S" on the screws and the captured washer on the bottom cover screws.

Thanks to all for their input and help on this issue!

Regards,

Jon