3/8” mechanical pump question

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Syleng1

Syleng1

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Does anyone know of a factory appearance looking mechanical fuel pump but with 3/8” inlet and outlet? I’m not looking for high flow or anything crazy. Mopar small block.

I converted a car to 3/8” from tank pick up all the way forward to carb 3/8”… because I could. I had the s/s 3/8” line and it kinda snow balled from there. Now I need a factory style pump that looks factory but is 3/8”

okay- go….
 
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Looking like an OE pump, no.
I use the Carter pump that resembles the Edelbrock pump. There fine for the street strip cars and a quick run at the track.
 
You want one with 3/8" NPT size fittings (not 1/4") or you are restricting down from your 3/8 line . JMO
 
Syleng1 said:
Does anyone know of a factory appearance looking mechanical fuel pump but with 3/8” inlet and outlet? I’m not looking for high flow or anything crazy. Mopar small block.

I converted a car to 3/8” from tank pick up all the way forward to carb 3/8”… because I could. I had the s/s 3/8” line and it kinda snow balled from there. Now I need a factory style pump that looks factory but is 3/8”

okay- go….
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You would need a NOS or used fuel pump for a 70 AAR Cuda or Challenger T/A. They used 3/8 fuel lines. Maybe try Nappa or Rock Auto for replacements for this engine as they were the only small block to use it due to the Six Pack /Six Barrell setup . 1350 CFM ! It needed higher flow LOL !!
 
Kendog 170 said:
You want one with 3/8" NPT size fittings (not 1/4") or you are restricting down from your 3/8 line . JMO
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Different measurements, to a degree.
A 1/4" NPT Pipe/fitting has about a 5/16" passage; a 3/8" barb fitting, on the other hand, only has about 1/4".
NPT, hose, flares, and lines are all measured differently. Makes piecing things together a convoluted mess sometimes... :)
 
AAndrews said:
You would need a NOS or used fuel pump for a 70 AAR Cuda or Challenger T/A. They used 3/8 fuel lines. Maybe try Nappa or Rock Auto for replacements for this engine as they were the only small block to use it due to the Six Pack /Six Barrell setup . 1350 CFM ! It needed higher flow LOL !!
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I don't believe the six pack 340's used 3/8 line. All fuel filters for those and other 70 340's are listed as 5/16.
 
That’s what the repop places sell for the 6 pack..
5/16 lines.
 
A56 said:
I don't believe the six pack 340's used 3/8 line. All fuel filters for those and other 70 340's are listed as 5/16.
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Hey A56,

Here's the info on the fuel lines from ALLPAR.COM. Check it out. Says the T/A and AAR were built with 3/8 fuel lines.

I can't say for certain that the fuel pump is different as it could have had some sort of adapter to use 3/8 lines.

I would think the mechanical fuel pump would be built the same as a 440 HP or a 426 Hemi as the 3- 2barrel carburation system was rated at 1320 cfm for the 340 T/A engines.

1970 Dodge Challenger R/T and Challenger T/A

Cheers!!
 
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Professor Fate said:
Different measurements, to a degree.
A 1/4" NPT Pipe/fitting has about a 5/16" passage; a 3/8" barb fitting, on the other hand, only has about 1/4".
NPT, hose, flares, and lines are all measured differently. Makes piecing things together a convoluted mess sometimes... :)
Click to expand...

Yup! Where high flow resistance is a concern I will check the inside diameter and ease or chamfer any internal steps.
Syleng1 said:
Does anyone know of a factory appearance looking mechanical fuel pump but with 3/8” inlet and outlet? I’m not looking for high flow or anything crazy. Mopar small block.

I converted a car to 3/8” from tank pick up all the way forward to carb 3/8”… because I could. I had the s/s 3/8” line and it kinda snow balled from there. Now I need a factory style pump that looks factory but is 3/8”

okay- go….
Click to expand...

How stock looking?
The Holley '110' 'Keith Dorton' will work - that's what I'm using on a LA with later passenger side water pump.
The 6 valve mechanical pumps I tried from MP and Edlebrock do not fit driver side water pump LA engines without mods.
The Edelbrock linked above may be smaller.
M6902 used to be OK in terms of fit a pump pressure. M6270 the pressure was too high for use without a regulator. Ryan Brown confirmed that by actually testing one for me.


As far as T/A and AAR passenger car models go, so far not seeing any documentation.
Would think such a change would show up in the TSBs if not in the FSM and parts books at the start of the year.
The 1970 Hamtramck Registry - 1970 T/A Challenger / AAR Cuda TSBs
 
Somebody got it wrong over on Allpar. None of the small blocks ever came with 3/8 line. Not even the AAR and T/A. Only the 440 Six Pack and the Hemi cars got it.
 
RustyRatRod said:
Somebody got it wrong over on Allpar. None of the small blocks ever came with 3/8 line. Not even the AAR and T/A. Only the 440 Six Pack and the Hemi cars got it.
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That's what I always thought . However, the T/A's were limited production homologated race cars so maybe they got something different. I just sent an email to Tony D'Agostino asking about this. If anyone knows the answer to this, he does.
 
AAndrews said:
That's what I always thought . However, the T/A's were limited production homologated race cars so maybe they got something different. I just sent an email to Tony D'Agostino asking about this. If anyone knows the answer to this, he does.
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Yup, I agree. I like Tony. Always done me right.
 
OP here: I understand all about diameters of the barbs and tubing flow rates and before I come across as harsh or a “Richard” because I’m not. I just figured with all the factory stuff being repopped as “modified” some company I was unaware of made a old style mechanical pump that was 3/8 inlet and outlet. Honestly I don’t need more flow. I wanted the pump and filter and rubber lines to match. I already had the 3/8 long s/s frame line so I had to buy a new sender so I went 3/8” then I made a very factory looking line from pump to carb at 5/16” and used a brass 3/8” to 5/16” barb to go from frame line to pump and it looks awkward as heck. So 70% of the job is 3/8 so I want to finish the job to make it 100% but don’t really need a HP Holley or carter fuel pump. If that’s what I need to do I will. Thanks everyone for your help!
 
Professor Fate said:
Yup, like that- the barb itself is sized to fit INSIDE of a 3/8 ID hose, so the barb OD is sized a hair over 3/8 (for a snug interference fit into the hose). If you figure a nominal wall thickness (of the barb) of 1/16", that knocks down the ID of the barb section of the fitting to 1/4". Fun, eh?
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I stand corrected.
 
Ok , just to follow up on the fuel pump with 3/8 lines. Here's the response from Tony D'Agostino .

You were dead on RustyRatrod !! AllPar was incorrect.


".....Al
fuel pumps are the same as a regular 340
and the fuel lines were 5/16"
only 440hps + hemis got the 3/8" fuel line with a vapor return..."

Cheers!!
 
Just to try to help out the OP,

Would there be enough material left in the 5/16 fuel pump inlet and outlet to tap it for a 3/8 fitting??

Just a thought...
 
AAndrews said:
Just to try to help out the OP,

Would there be enough material left in the 5/16 fuel pump inlet and outlet to tap it for a 3/8 fitting??

Just a thought...
Click to expand...

Great thought. If someone goes this route please post it. I wonder if it will lower the PSI ?
 
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