Fuel Pump Rebuild Kits

[Joe L.]

Re: Fuel Pump Rebuild Kits

Joe,

AC # 40193 = GM # 6415961 as per AC Delco fuel pump conversion chart dated 1987

The 6440193 (AC 40193) pump is listed for the following as per the AIM's:
65-66 Chevrolet 396 (L36 & L78)
66 Chevelle 396 (L36, L34 & L78)

The 6440248 (AC 40248) pump is listed for the following as per the AIM's:
65 Chevelle 396 (L37)
65 Corvette 396 (L78)
I believe that AC # 40248 = GM # 6415962

6440248 was replaced with 6440193 theoretically on 8/7/65 as per 66 Chevelle AIM.

The 6440366 (AC 40366) pump is listed for the following as per the 66 Corvette AIM:
66 Corvette 427 (L36 & L72)
AC # 40366 = GM # 6416245

GM # 6415962 was replaced with GM # 6416245 in Aug. 1967 as per Chev. Parts History.

Dave

Dave-----


The information I found regarding the applicability of the 40170 to 65-66 passenger car with 396/427 and 66 Chevelle with 396 came out of a 1989 edition of the AC Fuel Pump Catalog (excerpt attached). I find it hard to believe that this fuel pump, at least the screw-type "version" of it, was ever originally used for these applications and I don't see why it would ever even have been specified in SERVICE for these applications. As I mentioned previously, I am aware of no Mark IV big block applications that ever originally used a screw-type pump. The type 40193 as well as the type 40248 and 40366 you mention were all sealed type pumps.

I still find it hard to believe that the 40170 was converted from a screw type pump to a sealed type pump without a change in AC type number. I've never seen that much of a configuration change of any GM part without a change in part number and I've never seen an AC fuel pump change from a screw-type pump to a sealed type pump without a change in type number. If it actually happened here, it's the first and only time it ever happened. There's something "fishy" about this.

ACfuelpumpcatalogpage 001.jpg

[Michael M.]

Re: Fuel Pump Rebuild Kits

It is odd, if you Google the part #, you come up with both the screw type and sealed style pumps. One site specs this as an original ZL-1, L-88 fuel pump and wants big money for it. Some of the sites have the original box with the pump and the 40170 is listed on the box along with the 6415748 part number and it's a sealed type pump. I can assure you I bought this pump using the part number listing out of the Chevy Power catalog over 20 years ago and it is a screw type re-buildable pump. Very weird, but of course, just my luck since I would like to rebuild this pump.

[David L.]

Re: Fuel Pump Rebuild Kits

My 1987 issue of "AC-DELCO FUEL PUMPS & FLEXIBLE LINES" also lists the 40170 pump for the following:
65 396 Caprice, Impala
66 396 Chevelle
66 427 Caprice, Impala

It lists the 40193 pump for the following:
66 427 396 w/390 H.P. (Exc. Corvette)
66 396 w/325,360 H.P.

My "CHEVROLET POWER" catalog (5th edition, 1984) lists 6415748 as a "Fuel Pump High Capacity" as MARK IV service parts for iron block engine 396 to 454 CID and aluminum block engines 427 to 510 CID.

My 1967 Chev. Dealer Parts and Accessories Price Schedule (effective October 1, 1966) lists "+ 6415748" for $18.70 (list price), catalog code "AX"

code "A" = Master Parts and Accessories Catalog (P & A 30).
Nothing is listed for code "X".

"+" = Heavy Duty Parts see (P&A 30) Parts Catalog pages 59-60-61 for particulars.

Page 59-62 in my 1967 Chev. Parts Catalog (April 1967) is for "HEAVY DUTY OPERATION PARTS FOR PASSENGER AND CORVETTE (396 and 427 Engines with 4-Bolt Main Bearing caps)". Page 62 lists 6415748 for usage on 396 & 427 engines.

It appears that fuel pump # 6415748 (AC 40170) was only sold over the counter for high performance 396 & 427 engines.

Dave

[Joe L.]

Re: Fuel Pump Rebuild Kits

All------


Well, I acquired (not from eBay) one of these sealed (Unitec) type "GM #6415748" aka Delco type "40170" fuel pumps and it's just as I surmised---these are NOT what's labeled on the box. Obviously, this is an Airtex or Carter-manufactured pump (AC ceased the manufacture of mechanical fuel pumps in the mid-80's). However, it does have an AC type number stamped into the flange (later, these outsourced AC pumps had the type number laser-printed on the periphery of the cast pump body, but this one still had the stamped type number on the flange). The type number stamped is 40358. So, these are AC type 40358 fuel pumps packaged in a box that is labeled GM #6415748 and AC type 40170.

I'm sure this pump will meet the important performance specifications of the 40170 or it would not be so-packaged. No way is this some sort of GM/ACDelco mistake. Why did this happen? Well, I expect the pump's "metamorphosis" was somehow related to the transition from AC manufacture to Airtex or Carter manufacture. For some reason, probably arcane, the "substitution" of the 40358 for the 40170 occurred.

So, what's an AC type 40358? I don't know, for sure. However, as best I can tell (NOT confirmed) it was a fuel pump singularly used for 1966 Chevelle with L-78 (a rare application).


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[Timothy B.]

Re: Fuel Pump Rebuild Kits

Joe, I don't want to confuse things but that pump looks exactly like the AC 40509 service pump on my 67 corvette 300hp car.

[Joe L.]

Re: Fuel Pump Rebuild Kits

Joe, I don't want to confuse things but that pump looks exactly like the AC 40509 service pump on my 67 corvette 300hp car.

Timothy-----


A lot of Unitec-style pumps appear similar. However, there may be internal differences. In this case, though, there's more than internal differences. If one tried to install this pump on a small block, one would get into big trouble. That's because the pump rocker arm is different for small block and big block and this one has the big block arm.

[David L.]

Re: Fuel Pump Rebuild Kits

All------


Well, I acquired (not from eBay) one of these sealed (Unitec) type "GM #6415748" aka Delco type "40170" fuel pumps and it's just as I surmised---these are NOT what's labeled on the box. Obviously, this is an Airtex or Carter-manufactured pump (AC ceased the manufacture of mechanical fuel pumps in the mid-80's). However, it does have an AC type number stamped into the flange (later, these outsourced AC pumps had the type number laser-printed on the periphery of the cast pump body, but this one still had the stamped type number on the flange). The type number stamped is 40358. So, these are AC type 40358 fuel pumps packaged in a box that is labeled GM #6415748 and AC type 40170.

I'm sure this pump will meet the important performance specifications of the 40170 or it would not be so-packaged. No way is this some sort of GM/ACDelco mistake. Why did this happen? Well, I expect the pump's "metamorphosis" was somehow related to the transition from AC manufacture to Airtex or Carter manufacture. For some reason, probably arcane, the "substitution" of the 40358 for the 40170 occurred.

So, what's an AC type 40358? I don't know, for sure. However, as best I can tell (NOT confirmed) it was a fuel pump singularly used for 1966 Chevelle with L-78 (a rare application).


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Joe,

I did not notice this before (old age, I guess) but your 40170 pump that is stamped "40358" has a casting date of November 1966
("66" encircled with 11 dots in a clock like fashion).

Dave

[Richard M.]

Re: Fuel Pump Rebuild Kits

My NCRS member friend Chuck brought this over so we could photograph. Early magnesium pump stamped 40170 with a '66 date code under the bottom cover. Note the gussets on the upper magnesium casting, not shown in pics but has the "S" stamped screws. The number under the mount boss is PT 5623145

Chuck's not sure if this is OTC or TFP or ??.

Pics here and the next post, 4 at a time.

[Richard M.]

Re: Fuel Pump Rebuild Kits

DSCN0316.jpg DSCN0319.jpg DSCN0320.jpg DSCN0323.jpg

Note in main body date code 66 with 7 dots(2nd photo), and the "MADE IN USA" location on the flange.

[Timothy B.]

Re: Fuel Pump Rebuild Kits

I hope it's OK to ask this question about fuel pumps but what's the best way to test a pump. I have a pump to test for pressure and leaks but how does a fuel pump pressure relieve itself when the carburetor bowl needle and seat is closed.

If the camshaft rod is moving the pump lever but the fuel is not needed in the carburetor (like at idle), my thinking is that one of the fuel pump valves opens to let the fuel back into the other area of the pump, is that correct?

[Joe L.]

Re: Fuel Pump Rebuild Kits

Joe,

I did not notice this before (old age, I guess) but your 40170 pump that is stamped "40358" has a casting date of November 1966
("66" encircled with 11 dots in a clock like fashion).

Dave

Dave------


I believe it's actually 1999 which is also what the box flap indicates. If it had been manufactured in 1966 it would likely have had an "AC" embossed on the side of the casting. I believe this is either an Airtex or Carter manufactured pump. Most likely Airtex since Airtex uses the same type numbers as AC. They must have some sort of agreement with GM to use the same numbers. Also, this pump is configured slightly different than original AC-manufactured pumps. However, its general configuration (inlet valve style, inlet angle, outlet angle, etc.) is virtually identical to the 40358 in the eBay item.

[David L.]

Re: Fuel Pump Rebuild Kits

Joe,

I thought that it was a bit unusual. I have never seen a casting date on the side on a fuel pump made in 1966. I guess my mind as well as my eye sight are both going down hill.

Dave

[John D.]

Re: Fuel Pump Rebuild Kits

As I have mentioned numerous times most if not all the pump rebuild kits in the catalogs and local stores are not any good for ethanol.
Try: Jacksons Old Time Auto Parts sales@oldtimeparts.com 888-399-PART
They have a kit for ethanol but the gaskets don't come close to original appearance.
Once of the troublesome gaskets in a typical rebuild kit you will buy is the bottom cover gasket. The ethanol just eats the crap out of that gasket. Wrinkles it all up and the cover starts leaking. Resurfacing the cover and the bottom of the pump on a surface plate does not solve the problem. The problem is the gasket material.
Now if you have an old time NOS fuel pump the material in those gaskets will hold up longer than a repro fuel pump kit from various catalogs.