Fuel pump date code? David Liukkonen

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

David, you got great feedback fast over there, encouraging.

I do think you have to split the study into two parts, late 60's and early 70's where the difference is a two digit code versus a 4 digit code.

Give that - under normal circumstances, look at the dates and make sure they make sense - meaning that 6H if it is to imply Jan 6 68 is a Saturday. Could be someone worked some OT, but back then doubtful that it was the norm.

How many dates do you have on C2 pumps? And how to they fit with the days of the week?

[Gerard F.]

Re: Fuel pump date code? David Liukkonen

David,

Just a thought here. Your date coding theory on fuel pumps and the change in date coding seems to run parallel to Holley carb date coding, although the breakpoint may be different.

65 to 72 GM production Holley carburators were date coded with a 3 digit date code of year-month-week. After the 72 production year, Holley carbs switched to the 4 digit julian date coding of day of the year followed by the year.

Maybe there was some GM directive or other regulation that made the date coding specific to the day on fuel systems.

As I said above and for what it is worth, the FG on my 67 40433 fuel pump fits your theory and all other engine drivetrain parts on my late June 67 Corvette (VIN 22049).

[Tom F.]

Re: Fuel pump date code? David Liukkonen

Jerry:

I just checked out an Airtex electric fuel pump that I have. On the front label and also on the pump itself there is a three didgit number 378. I know for a fact that the pump was manufactured the 37 week of 2008. I can't say it holds true for mechanical pumps, but just a thought.

[David L.]

Re: Fuel pump date code? David Liukkonen

The Camaro Research Group Forum has a post about a "HH40669" fuel pump (where "HH"= August 1968, I believe) on a 1969 Z28 with a October 1968 body build date and a 0912DZ engine stamp (September 12, 1968).
The original post was on 12/04/2007.

[Terry M.]

Re: Fuel pump date code? David Liukkonen

I was quoting what I thought I saw for numbers and letters in this photo. I'll clean up the fuel pump and see what I can find.

The engine assembly date is V0114CTU (January 14, 1970) Since the fuel pump was installed on the engine at St Louis the body build date of A29 (January 29, 1970) might be more significant.

I bought the car new, so I am as sure as I can be that this is the original fuel pump installed at St. Louis.

OK, let's try the cleaned up version:

I think it is LN, but even looking at it under magnification I can't tell for sure. I still maintain judging this stamp ont he car would be a crap shoot at best.
Neat diamond shape stamped on the bottom.
If you could call it November of 1969 it would work perfectly.

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

Terry, can you post a pic with the PN and code - and - the diamond together, I want to compare to the 65 BB pump I have.

"IF" the letter "L" referred to a year - what is the alpha sequence?

"IF" the letter "L" referred to a month - what is the alpha sequence?

David - and those stamped with one number and one letter?
Coincidentally all "H"???

I say H has nothing to do with date coding as we are accustomed...

My 2 cents is H is one of the plants that made these, and that Diamond is real intriguing.

[David L.]

Re: Fuel pump date code? David Liukkonen

OK, let's try the cleaned up version:

I think it is LN, but even looking at it under magnification I can't tell for sure. I still maintain judging this stamp ont he car would be a crap shoot at best.
Neat diamond shape stamped on the bottom.
If you could call it November of 1969 it would work perfectly.

Terry,

It looks like "LH 40709" to me which I believe would be dated Dec. 1968 ("LH").

On Feb. 10, 2010, I posted information about a "HH40669" pump (where I believe "HH" = August 1968) that was originally on an early 69 Z28 (engine code "0912DZ", Sept.12, 1968).

I may be right or I may be wrong but I really think that I am right but only time will tell.

Dave

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

David -

With all your data 1970 and prior I bet if you shared that we could crack the code.

But - theory time:
#1. Assume that for each year the PN was changing on motor & application.
The data I have:
1965 427 40248
1966 427 40366
1967??? 427 40482*** need to see the pump and car data

#2. The L on the data point of one says L = November, a common parts identifying scheme back then.

#3. The H that shows up a number of places has to do with the plant,
Plant H in Flint or the Line on which these pumps were run.

Why would they need to put the year on there when they were changing the part number every year anyway???

The issue is we have no back correlation to the numbers I have seen on 66 pumps, 6H, 4H.

So if you have data from known original owner cars...

[David L.]

Re: Fuel pump date code? David Liukkonen

Another example from the nasty Z28 website:

"DJ40726" fuel pump where I believe "DJ" = April 1970
Body build date of 1970 Z28 is "04D" (4th week of April 1970).

I give up with those who wear blindfolds.

[Mark D.]

Re: Fuel pump date code? David Liukkonen

I still maintain judging this stamp ont he car would be a crap shoot at best.

Terry,

I think myself and my buddy Bosselman need to start trying to pull these numbers during judging. It would give us something to do (keep us out of the bars) and perhaps we could build a database although I'm sure David is WAY out in front of me on that idea.

I'm thinking I need to judge the driver's side...

Mark

[Terry M.]

Re: Fuel pump date code? David Liukkonen

David -

With all your data 1970 and prior I bet if you shared that we could crack the code.

But - theory time:
#1. Assume that for each year the PN was changing on motor & application.
The data I have:
1965 427 40248
1966 427 40366
1967??? 427 40482*** need to see the pump and car data

#2. The L on the data point of one says L = November, a common parts identifying scheme back then.

#3. The H that shows up a number of places has to do with the plant,
Plant H in Flint or the Line on which these pumps were run.

Why would they need to put the year on there when they were changing the part number every year anyway???

The issue is we have no back correlation to the numbers I have seen on 66 pumps, 6H, 4H.

So if you have data from known original owner cars...

The pump for the LT1 ran for three years in PRODUCTION, and was available in service for many more years, so the "changing numbers every year" doesn't hold water. I would imagine there are a lot of other fuel pumps with multi-year PRODUCTION runs also.

[Terry M.]

Re: Fuel pump date code? David Liukkonen

Terry,

I think myself and my buddy Bosselman need to start trying to pull these numbers during judging. It would give us something to do (keep us out of the bars) and perhaps we could build a database although I'm sure David is WAY out in front of me on that idea.

If either of you guys think you can get under there to even see these numbers, you have already been in the bar too long. I've got this one in my hand and if you want I'll bring it to Gettysburg, and you will not be able to read it any better than from these pictures.

I'm thinking I need to judge the driver's side...

Mark

Lots of luck.

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

We just need data guys, if we had the numbers off 50 pumps per year from 64 - up to the time they went to the 4 digit code, we could solve this in a matter of hours, if not minutes.

So those guys that volunteer to get pics, write down the data from car build dates and motor type, send it over, I'll start an excel file.

[Ronald L.]

Re: Fuel pump date code? David Liukkonen

The folks at AC were card players, Terry has a Diamond, and while up at Paragon the other day, their 66 40366 pump has a ---heart shape---stamp over in that same area. I think the two digit was AF...

[Dave S.]

Re: Fuel pump date code? David Liukkonen

The Camaro Research Group Forum has a post about a "HH40669" fuel pump (where "HH"= August 1968, I believe) on a 1969 Z28 with a October 1968 body build date and a 0912DZ engine stamp (September 12, 1968).
The original post was on 12/04/2007.

This 709 fuel pump came off my 71 LT-1. As you can see it is stamped 8K40709. The motor has a 330CGZ stamp so it was assembled on March 30, 1971.