'68 Fuel Pumps / Carb Line - ClassicOldsmobile.com

Tech Editor's Desk Projects, papers, writings, thoughts, musings of our technical editor Joe Padavano. To begin with, he will be making threads and can approve posts to it if he wishes. This can be changed in the future if it does not work out well.

'68 Fuel Pumps / Carb Line

Old August 17th, 2012, 02:35 PM
  #1  
Registered User
Thread Starter
 
Indy_68_S's Avatar
 
Join Date: Oct 2009
Location: Central IN
Posts: 1,207
'68 Fuel Pumps / Carb Line

Thought I'd post an issue I discovered during my resto.... Please chime in if anything is incorrect....

Common replacement fuel pumps are Carter M6108 (no return) & M6109 (has return). I tried to use a M6109 (I added a return) and discovered that the '68 is a bit different from the common '69 & up.

The '69 & up carb line screws directly into the pump and the flare block is angled up.

The outlet for the '68 is clocked a bit different, is not flared, outputs parallel to the top of the pump, and requires a 90 brass fitting to receive the carb hard line.

The M6108 & M6109 are the later style ...aka '69 & up

The Carter (or NAPA) M4871 (no return) and M4516 (has return) are the proper replacements for a '68 that uses the brass 90 fitting.

Also, if you order a so-called '68-'72 hard line, you will probably get the later style... I know the 6802 line from Fusick or ILT is for the later style. You can make this line work with some massaging but its a pain.

Pics:
1 - ILT 6802 hard line (unmolested) w/ M4516
2 - Orig OEM fuel line w/M4516
3 - Massaged 6802 line
4 - Carter M6108 (later style - no return)
5 - Carter M4871 ('68 style - no return)
Attached Images
File Type: jpg
DSC04753.jpg (41.4 KB, 95 views)
File Type: jpg
DSC04751.jpg (55.5 KB, 90 views)
File Type: jpg
DSC04754.jpg (47.4 KB, 94 views)
File Type: jpg
180-M4871.jpg (11.0 KB, 79 views)

Last edited by Indy_68_S; November 24th, 2015 at 05:28 AM. Reason: corrected part numbers
Indy_68_S is offline  
Old November 23rd, 2015, 06:10 PM
  #2  
Registered User
 
Leadfoot's Avatar
 
Join Date: Feb 2014
Location: Indiana, USA
Posts: 191
This is great info. I'm surprised nobody had commented on it before. I've found that Right Stuff makes the lines for ILT, Fusick, Parts Place, and probably Summit, among others. If you check, those vendors use almost the exact same part number as Right Stuff. And it seems that even Right Stuff doesn't always know what they're selling for these engines. I sent them an email over the weekend asking if their 6801 line was bent for pumps with 90 degree or 45 degree outlet fitting, and their answer was that it was for the 45 degree and the #6802 was bent for the 90 degree. I checked the photos of both, and they look not at all alike (maybe the photo is wrong?). The 6802 is listed for 350's with 4bbl carbs, while the 6801 is for 2bbl. Both are listed for '68-'72.

What threw me is that the '68-'69 pumps had the 90 degree outlet fitting, while the '70+ had the 45 degree outlet. I think I also heard that the style change happened sometime during the late '69 production year. But almost nobody makes a 45 degree outlet pump -- I think Carter is the only manufacturer I found that still makes one. So I needed a line for the 90 degree outlet, couldn't find one anywhere, and finally had it confirmed by your info that I just need a 90 degree flare elbow. Thanks for solving that mystery for me...
Leadfoot is offline  
Old November 24th, 2015, 03:36 AM
  #3  
Registered User
 
Join Date: Dec 2011
Posts: 7,286
adding to database for easy reference

4615 or 4516 ??



Originally Posted by Indy_68_S View Post
Thought I'd post an issue I discovered during my resto.... Please chime in if anything is incorrect....

Common replacement fuel pumps are Carter M6108 (no return) & M6109 (has return). I tried to use a M6109 (I added a return) and discovered that the '68 is a bit different from the common '69 & up.

The M6108 & M6109 are the later style ...aka '69 & up

The Carter (or NAPA) M4871 (no return) and M4516 (has return) are the proper replacements for a '68 that uses the brass 90 fitting.

Pics:
1 - ILT 6802 hard line (unmolested) w/ M4615
2 - Orig OEM fuel line w/M4615
3 - Massaged 6802 line
4 - Carter M6108 (later style - no return)
5 - Carter M4871 ('68 style - no return)
Octania is offline  
Old November 24th, 2015, 03:58 AM
  #4  
Registered User
 
Leadfoot's Avatar
 
Join Date: Feb 2014
Location: Indiana, USA
Posts: 191
The correct Carter number is M4516.

http://carter.opticatonline.com/part...ical-fuel-pump
Leadfoot is offline  
Old November 24th, 2015, 05:27 AM
  #5  
Registered User
Thread Starter
 
Indy_68_S's Avatar
 
Join Date: Oct 2009
Location: Central IN
Posts: 1,207
Good catch, Octania.
Originally Posted by Leadfoot View Post
The correct Carter number is M4516.

http://carter.opticatonline.com/part...ical-fuel-pump
Yes. Leadfoot is correct. I must've dyslex'd out for a few seconds there.

Original post has now been corrected.
Indy_68_S is offline  
Old November 24th, 2015, 06:19 AM
  #6  
Registered User
 
Join Date: Dec 2011
Posts: 7,286
M4871 "Pump, Fuel pump, 2-line, no return. Carter / NAPA PN's
64?-mid '69?, Horizontal NPT outlet requires 90 degree adapter to inverted flare
Use xxx line"

M4516 "Pump, Fuel pump, 3-line, with return, typically AC/HDC or W31 cars
64?-mid '69?, Horizontal NPT outlet requires 90 degree adapter to inverted flare
Use yyy line"

M6108 "Pump, Fuel pump, 2-line, no return
mid '69? &+, inverted flare outlet is angled up ~45 degrees
Use 6802 pump to carb line for this later style pump, with some massaging. "

M6109 "Pump, Fuel pump, 3-line, with return, typically AC/HDC or W31 cars
mid '69? &+, inverted flare outlet is angled up ~45 degrees
Use 6802 pump to carb line for this later style pump, with some massaging."

Is more or less what I have now.
Unknown fuel line PN for early pump requiring 90' adapter.
Maybe I missed it or deleted it


corrections appreciated.
Octania is offline  
Old November 25th, 2015, 03:36 AM
  #7  
Registered User
 
Leadfoot's Avatar
 
Join Date: Feb 2014
Location: Indiana, USA
Posts: 191
Originally Posted by Octania View Post
M4871 "Pump, Fuel pump, 2-line, no return. Carter / NAPA PN's
64?-mid '69?, Horizontal NPT outlet requires 90 degree adapter to inverted flare
Use xxx line"
According to Right Stuff Detailing, this application should use their #APC6802 pump to carb line without an angled adaptor. Not verified.

M4516 "Pump, Fuel pump, 3-line, with return, typically AC/HDC or W31 cars 64?-mid '69?, Horizontal NPT outlet requires 90 degree adapter to inverted flare
Use yyy line"

Again, according to Right Stuff Detailing, this application should use their #APC6802 pump to carb line without an angled adaptor. Not verified.

M6108 "Pump, Fuel pump, 2-line, no return
mid '69? &+, inverted flare outlet is angled up ~45 degrees
Use 6802 pump to carb line for this later style pump, with some massaging."

According to Right Stuff Detailing, this application should use their #APC6801 pump to carb line without an angled adaptor. Not yet verified.

M6109 "Pump, Fuel pump, 3-line, with return, typically AC/HDC or W31 cars mid '69? &+, inverted flare outlet is angled up ~45 degrees
Use 6802 pump to carb line for this later style pump, with some massaging."

According to Right Stuff Detailing, this application should use their #APC6801 pump to carb line without an angled adaptor. Not yet verified, but will be.

Is more or less what I have now.
Unknown fuel line PN for early pump requiring 90' adapter.
Maybe I missed it or deleted it


corrections appreciated.

It should be noted that what Right Stuff lists on their web site/catalog differs from what I was told on the phone. Their site lists the #APC6802 line for 1970-71 4bbl applications. On the phone I was told it was the correct line for 90 deg. outlet pumps and 2bbl carb. Aren't the carb inlets located differently between the 2bbl and 4bbl carbs? I only have the 2bbl.

Right Stuff lists the #APC6801 line for the 45 degree outlet pumps used in '70-71 and with 2bbl carbs. I have one of these lines ordered, so I'll see how it fits with both types of pumps and report back. I may end up ordering a #APC6802 line as well to see for myself which line will work better.

Now this is important: If you need an adapter, you can't use just any old adapter fitting. Because the (pump to carb) hard line is flared on both ends, the pump's outlet port should be a reverse flare configuration (just like the carb inlet/filter fitting), but not all are. Some are just threaded (should be FPTF, 'Female Pipe Taper Fuel, but may be FPS, Female Pipe Straight). The manufacturers and retailers don't tell you what the thread is in their basic specs. Some also are threaded with a tapered seat for SAE male flare fittings. Adaptors for the threaded outlets are pretty readily available in straight or 90 degree (street) ells (see Eaton Weatherhead #
402X6X6, available at Fastenal and elsewhere).
If the pump has an inverted flare outlet, it's designed to connect directly to the line with no adapter, and requires a flared fitting to seal; and there is no single 90 degree ell fitting made that will mate and seal at both the pump and the line flares. It would require a male flare x female inverted flare which nobody makes in a 90 degree (or 45, as far as I can tell) ell.

The most important thing is to look at the pump outlet to see what connection is required. If it is not an inverted flare, then you MUST use an adapter of some kind (with an inverted flare) to mate with the line flare. Then figure out if you can get the adapter you need, if any.

I hope that helps some.

Once I get the Right Stuff #6801 line, I'll report back on how it works with either style of pump.

Leadfoot is offline  
Old November 25th, 2015, 03:46 AM
  #8  
Registered User
 
Leadfoot's Avatar
 
Join Date: Feb 2014
Location: Indiana, USA
Posts: 191
I meant to post this link for reference and forgot. It's a good quick reference for basic threaded fitting standards and what works with what.

http://pipeandhose.com/node/1

If that link becomes dead in the future, just try pipeandhose.com in your browser.

JP
Leadfoot is offline  
Old November 28th, 2015, 05:02 AM
  #9  
Registered User
 
Leadfoot's Avatar
 
Join Date: Feb 2014
Location: Indiana, USA
Posts: 191
Just for comparison... Here is the original pump from my '69 next to the replacement Airtex/NAPA #40523, which looks, for all fitment purposes, identical to the Carter M4516. Note that the fuel outlet, in addition to being 90 degrees vs 45 degrees, is clocked differently, as Indy_68_S mentioned.




From a different angle, you can see that the original pump has an inverted flare fitting, so no adapter fitting is necessary or desirable. The Carter and Airtex pumps have a threaded-only outlet (no inverted flare), so an adapter of some kind with an inverted flare will be necessary.

Leadfoot is offline  
Old November 28th, 2015, 05:14 AM
  #10  
Registered User
 
Leadfoot's Avatar
 
Join Date: Feb 2014
Location: Indiana, USA
Posts: 191
My original hard line (pump to Rochester 2bbl carb), next to the equivalent replacement Right Stuff Detailing #APC6801 line. The bends are in different locations, but similar enough that this may work well.





The biggest difference between the two lines is that the 6801 line has the double 90 degree bends much closer to the carb. But the overall length and the angles at the ends are pretty close. I don't know if my original line had ever been 'adjusted', but based on the 90 degree bends, I think it had.
Leadfoot is offline  
Old December 7th, 2015, 01:52 AM
  #11  
Registered User
 
Leadfoot's Avatar
 
Join Date: Feb 2014
Location: Indiana, USA
Posts: 191
Below is the Right Stuff Detailing #APC6801 line installed. The fit was actually pretty good. Some adjustments were necessary, particularly to get things to align at the carb end, but I managed to achieve a perfect fit with minor massaging. Note again that this is the NAPA/Airtex #40523 pump, '69 350 with a/c and the original 2bbl Rochester carb.
The brass adapter I found in stock at a local O'Reilly Auto. It is Edelmann part #122640, 3/8" female inverted flare x 1/4" MPT, 90 degrees. I used teflon tape on the adapter male thread for the final assembly. Do nut use a liquid thread sealer, as they are not suitable for use with liquid fuels. Always dry fit everything first. Then note and accurately mark the orientation/rotation of the adapter fitting. You want to final install that adapter by tightening only - if you need to loosen it to get it into the right orientation, you are inviting leaks.

Leadfoot is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
70 ctls
General Questions
3
March 17th, 2015 09:18 AM
Del70
General Discussion
22
November 15th, 2013 02:24 PM
RAMBOW
Racing and High Performance
4
July 30th, 2013 03:40 PM
davepnola
Chassis/Body/Frame
4
December 2nd, 2010 09:00 PM
68conv455
Other
3
May 20th, 2008 02:03 PM


Thread Tools
Search this Thread
Quick Reply: '68 Fuel Pumps / Carb Line


Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.